Water flowed from the cistern through the 1.5 miles of piping and dropped 700 feet in elevation en route to the site. Once water reached the grow site, the large PVC fed into progressively smaller tubing that connected drip irrigation lines to each plant. This system utilized control valves to prevent overwatering and to regulate watering schedules. In the case of small operations, the water is sometimes stored at the site in large plastic lined reservoirs or large storage tanks. The water is then pumped from the reservoir on regular schedules through drip irrigation lines in quantities that optimize growth. Water diversion practices create adverse effects for humans and the environment alike. When the natural flow of water from springs or ephemeral creeks is modified, the preexisting flora and fauna that rely on it are deprived. As surface level water disappears, riparian vegetation and animals have limited access to the water that they depend on. More seriously, keystone fish species die from degradation and loss of habitat. As one species cannot sustain its diet, it dies off, leading to the death of other species that predate upon it. Water diversion practices significantly impact human society as well. The state of California has abundant water resources that are necessary to sustain its vast population,economy, and natural environments. Though the overall fresh water supply from precipitation is immense, the public demand for fresh water far exceeds the natural supply. The consequence is that California is effectively experiencing a water crisis resulting in agricultural drought, dry racks for weed economic and natural devastation, and limiting water availability for California residents. Water diversion practices for marijuana cultivation serves only to further exacerbate the issue during the most critical drought months.

Water flow assessments estimate that an average of 650,000 gallons of water goes unaccounted for in California every day throughout the year. Estimates of unaccounted water during the summer months can reach numbers as high as 3.6 million gallons per day. This over consumption depletes groundwater resources causing lowlands to subside below sea level, rivers to dry up, and salt water from the ocean to intrude and contaminate California’s primary fresh water source the Sacramento San-Joaquin River Delta. Changes in water quantity cause the temperatures, pH, and salinity of lakes, rivers, and canals to increase. These decreases in water flow and reductions in water quality reduce the amount of viable breeding habitat for the sustenance and restoration of aquatic species. The direct correlation between water consumption and marijuana bud production creates a large incentive for marijuana cultivators to heavily irrigate their crops. Remote cultivators extract water in mass quantities, blatantly “degrading the public water trust because they are divorced from the foundation of [American] laws.” Due to the illegal status of marijuana cultivation, growers experience limited liability for their diversion practices within the state of California, because they are outside of the realm of institutional oversight. Their access to water is difficult to obstruct because they extract water from the top of watersheds. Thus, they act in disregard for human communities, flora, and fauna that depend on reliable sources of fresh water. When Cannabis cultivators exploit over-extended water supplies, California is forced to extract increasing amounts of water from the Colorado River and other sources, for which the citizens of California and other areas foot the bill.As in industrial agriculture, chemicals are applied in order to create plants that are fast growing, develop specific desired traits, and have an optimized yield. For the Cannabis plant, this means maximizing bud production, increasing THC levels and preventing any damages from deer, rodents, mites or mold.

An average cultivation site of about 5 acres and 7,000 plants can contain 20 pounds of rat poison, 30 bags of fertilizer, plant growth hormones, insecticides, herbicides, fungicides, and a variety of other chemical inputs. The key difference between industrial agriculture and marijuana cultivation is that Cannabis cultivators are not subject to government or industry regulations. DTO’s import banned chemicals from Mexico which they apply in unrestricted amounts, causing extensive harm to the laborers and to the ecosystems exposed. It is estimated that 1.5 pounds of fertilizer is used for every 10 plants. Excess nutrients not taken up by plants are washed into lakes, rivers, streams and the ocean during periods of precipitation. These fertilizers cause nutrient imbalances with varying effects. Residual toxic compounds “enter and contaminate groundwater, pollute watersheds, kill fish and other wildlife, and eventually enter residential water supplies.”61 The marijuana mono-cultures that Mexican DTOs create are especially susceptible to damage and infestation, causing cultivators to take preemptive measures to protect their plants. Four of the foremost threats to Cannabis plants are mold, mites, rats and Deer. Cultivators spray sulfur dioxide and pesticides directly onto Cannabis plants in order to combat mold and mite problems. Excess sulfur gas and sulfate particles diffuse into the atmosphere, high exposure to which can cause respiratory effects in humans and animals ranging from shortness of breath to respiratory diseases and premature death. In the environment, sulfur dioxide is the leading source of haze in national parks. More importantly, sulfur dioxide in the atmosphere leads to acid rain that “damages forests and crops, changes the makeup of soil, and turns lakes and streams acidic which causes unsuitable” conditions for aquatic life. Acidic precipitation occurs in the form of rain, fog, snow, and particulates that can travel in winds for hundreds of miles, causing damage to plants, buildings, and monuments along the way. One of the most notable chemicals that is used to combat mite infestations is Dichloro-Diphenyl-Trichloroethane .

DDT was banned in the United States in 1973 after scientific research led to public outcry over its adverse effects on human health and the environment. DDT can persist in the environment for up to fifteen years because it binds to soil and bioaccumulates in plant materials and the fatty tissues of animals such as fish and birds. DDT is a carcinogen that damages the nervous system , reduces reproductive success, and causes cancer to the liver. Despite the known health hazards posed by DDT, people throughout the world have been subjected to acute exposures through food consumption and inhalation. Another commonly used pesticide is Malathion, which is a synthesized organophosphate insecticide. 64 When Malathion enters the environment it has little harmful effects because it is broken down rapidly by bacteria in soil and water, and by UV radiation when it enters the atmosphere. However, direct “exposure to high amounts of Malathion can cause difficulty breathing, tightness in the chest, vomiting, cramps, diarrhea, blurred vision, sweating, headaches, dizziness, loss of consciousness, and possibly death,” all symptoms which are most likely to be experienced by on-site laborers who do not wear proper respiratory protection. The methods that cultivators use to apply chemicals are especially hazardous. At best, cultivators wear long sleeves, pants, and thin polypropylene masks as protection, all of which are inadequate for preventing significant exposure to chemical toxins. Laborers use hand held spray systems to administer chemicals in liquid or gaseous form. They are subjected to concentrated chemicals for prolonged periods, causing high rates of exposure through inhalation and contact with clothing and exposed body parts. However, cultivators are not the only group risking exposure through direct contact. Chemical residues can persist on marijuana buds, resulting in exposure when buds are consumed. Another threat to marijuana plantations is that “marijuana stalks are very appetizing to deer and rodents that chew the stalks of the plants.” To combat this problem, drying rack weed growers use rat poison pellets to kill rodents, and rifles to kill large mammals. Chemical repellents and poisons are applied at or near the base of the Cannabis plants and around the perimeter of plantations to kill rats, deer, and other animals that could cause crop damage. “The poison kills the animals close by, and when the bodies decompose,” these poisons enter into the water table and contaminate soil and wildlife that come into contact with the polluted water. Contaminants accumulate in small biotic creatures, which are then eaten by larger animals causing progressively concentrated levels of toxins within the tissue of large predators. Ultimately, this can lead to the death of large animals and the consumption of toxins by humans.Sustained inhabitance at remote locations is one of the crucial distinctions between outdoor marijuana cultivation sites operated by Mexican DTOs and those operated by other groups. Mexican nationals inhabit sites over a period of three to five months in order to prepare the landscapes, maintain plants, and aggressively protect their plantations. On average, two to five people live on the site throughout the season while a total of ten to fifteen actively aid in supplying materials and preparing grow systems. These men ensure that the site is properly equipped, concealed by camouflage, and guarded against detection and seizure.Cultivators rely on sufficient tree canopy as the primary camouflage for Cannabis plantations. They plant marijuana in areas where the sunlight reaches through the holes in the trees, but the tree cover is sufficient to obstruct the view of plants from an aerial perspective.

Cultivators cut down trees strategically in order to let in more sunlight while maintaining obstruction to aerial detection. They then spray green spray paint and other colorings on stumps to mask the reflectivity of freshly cut wood. In more exposed areas, marijuana is sometimes interspersed with legitimate commercial agriculture to prevent visual detection. In addition, inhabitants paint camouflage patterns and netting to hide camp equipment and tents that do not blend in with the natural environment. Cultivator concern for concealing their activity is limited to arboreal camouflage. Inhabitants contaminate sites by littering the ground with garbage including cook ware, stoves, empty propane tanks, extendable pruning saws, excess plastic irrigation hose, tarps, beer cans, plastic wrappers and many other forms of refuse. Dug out latrines contain months worth of excrement and excess chemicals. In Sequoia National Park in 2007, the California Army National Guard and the California Air National Guard cleaned up resident-camp infrastructure from 11 grow sites and 9 camps that were occupied by growers. In this effort they removed 5,600 pounds of garbage, including 75 propane canisters and 5.8 miles of irrigation hose.68 In addition to leaving trash, some cultivators construct and leave fences around cultivation plots. They build deer fences that are 6-10 feet tall around planted areas with standard chicken wire, cattle fence, plastic netting, or livestock wire. These fences act as barriers to faunal migratory pathways and tangle animals in the netting or micro-filaments. Wildlife is also impacted directly through cultivators’ use of high powered weaponry. Many sites have scattered carcasses of deer and bears that were poached by laborers, who shoot almost anything that comes near their site. This aggressive behavior protects the plants and provides supplemental protein in the laborers diet. However, the vast majority of these carcasses are left to rot and to be eaten by vultures because growers cannot viably consume or preserve all of the meat from large mammals before it rots. The scavengers that successfully feed on carcasses have an increased risk of developing lead poisoning because they begin eating at the point of bullet entry where inner flesh is the most exposed and easily accessible. By eating from a gunshot wound, scavengers consume bullets containing lead. Over time, lead can accumulate in their bodies and cause lead poisoning. Lead poisoning caused by hunting is cited as the number one killer of the California condor, an endangered species, and poses one of the most significant threats to wild scavengers in California. Sustained inhabitance poses a significant hazard to fire prone areas throughout California. Cultivator activity can cause wildfires and the presence of a marijuana garden obstructs firefighting efforts due to safety issues. “On the Hume Lake Ranger District of the Sequoia National Forest, a wildfire in 1999 was started by a campfire in a marijuana garden. Firefighters found the garden and had to stop fire suppression activities in the area until law enforcement secured the area. This problem occurs several times every year.” Cultivators use campfires and burn volatile gases for cooking during the dry season in areas vulnerable to fire. Under prime fire conditions, a stray spark, improperly connected tank, or overturned stove can initiate an out of control fire with drastic and widespread consequences.

Upon arrival to the ED, her vital signs were temperature of 36.4°C, heart rate of 96bpm, blood pressure 148/111mmHg, and respiratory rate of 11. She was difficult to redirect and her mental status revealed a thin, “nervous,” well-groomed woman with a labile affect and pressured speech. The patient’s thought process was loose and disorganized with thought blocking. She was paranoid, grandiose, hyper-religious, and endorsed auditory hallucinations. She denied suicidal or homicidal ideation. Her attention and memory were considered impaired though not formally tested.The patient admitted to using cannabis lip balm and consuming edible cannabis chocolate bars daily over the past week, most recently the day of presentation. She could not quantify her consumption. She believed her paranoia and insomnia onset coincided with her THC ingestion last week. The patient denied other recent substance or alcohol use. She denied any falls or history of traumatic brain injuries. A friend of the patient confirmed this history. Her other medications included propranolol 20mg twice a day for hypertension and infrequent sumatriptan as needed for migraines. Family history of mental illness was unknown since the patient was adopted. For this presentation of acute psychosis, emergency medical providers conducted a comprehensive work-up to exclude organic etiologies of psychosis or concurrent medical morbidity. A basic metabolic panel was significant for a potassium level of 3.2mg/dL ; her electrocardiogram demonstrated a prolonged QTc of 508ms, a pulse of 86, curing weed and no U waves or T wave changes. A 9-carboxy-THC level was over 500ng/mL; her urine toxicology screen was negative for cocaine, amphetamines, benzodiazepines, and opioids. A B12 level was elevated at 1186pg/mL. Her complete blood count and a noncontrast head computerized tomography study were unremarkable.

The patient refused supplemental potassium, and it was thought that her EKG findings did not warrant emergent, forcible repletion. She also removed her intravenous line while agitated. She was placed in two-point soft restraints for her safety. After consultation with psychiatry, the patient was deemed medically appropriate for transfer to the ED’s psychiatric emergency service for further evaluation and treatment. In the PES, the patient was hypersexual, hyperactive, and intrusive, entering other patients’ rooms and touching them. As she could not be safely re-directed, physical restraints were again ordered for the patient’s and others’ safety. Risperidone 0.5mg PO q6hr and lorazepam 1mg PO q6hr were ordered as needed for management of psychosis and anxiety; the patient required one dose of each during her PES stay. Twenty-four hours after presentation, her psychotic symptoms and anxiety persisted: she suggested that her food was poisoned and asked whether she was African-American . The patient claimed to have forgotten her father’s name, did not know where she was currently living, and was oriented only to person and place. She received her scheduled propranolol for hypertension and 40meq of oral potassium chloride . Her consciousness and attention were intact. Forty-eight hours after presentation, the patient’s paranoia and hallucinations improved dramatically. The patient was able to reflect on the unreality of her paranoia and “odd thoughts” of being African-American. With improved insight, she confirmed heavy use of multiple edible THC products in addition to frequent coffee and energy drink consumption, which she had difficulty quantifying. The patient was diagnosed with cannabis-induced psychotic disorder and severe marijuana use disorder; she was instructed to follow up with outpatient mental health to ensure resolution of her psychosis and begin substance abuse treatment.New-onset psychosis is a medical emergency with a broad differential. 

Signs and symptoms concerning for a medical etiology of psychiatric symptoms include abnormal vital signs, altered consciousness, or lack of prior psychiatric history in a patient over 40 years old. The acute onset of symptoms with marijuana use, high serum marijuana metabolite levels, and symptomatic resolution with detoxification suggest these symptoms were secondary to marijuana use. Cannabis-induced psychotic disorder is diagnosed when psychotic symptoms persist beyond acute intoxication and may require clinical management. Psychiatric symptoms include paranoia, derealization, disorganized thinking, persecutory and grandiose delusions, hallucinations, and cognitive impairment. Patients pose a danger to others and themselves due to their altered sense of reality. Safe cannabis detoxification typically requires 24 hours, but sometimes longer for patients with unstable vital signs and persistent psychosis. Benzodiazepines are recommended for agitation related to stimulant intoxication – unless psychosis is present, in which case oral atypical antipsychotics are considered first-line. Cannabis blood levels reflect the extent and chronicity of marijuana use. A free THC level below 3ng/mL suggests occasional consumption while a concentration higher than 40ng/mL corresponds to heavy use . Levels above 10ng/mL impair motor function, leading two states with legal recreational marijuana to establish the legal limit for driving at 5ng/mL. In clinical practice, measuring an inactive metabolite of THC, 9-carboxy THC, is preferred due to the rapid decrease in free serum THC levels. In a prior case report, oral cannabis-induced psychosis resolved within 24 hours after recorded serum THC levels below 20ng/mL, or 9-carboxy-THC levels below 50ng/mL; the authors suggested that oral administration may not achieve high serum THC levels. Our patient’s 9-carboxy-THC level over 500ng/mL demonstrates that oral administration can achieve high serum THC levels and suggests a dose-response relationship between serum metabolite levels and the severity of psychosis. Moreover, serum drug levels may anticipate a patient’s clinical course. THC enhances sympathetic tone, thereby increasing heart rate and blood pressure. Marijuana increases the risk of myocardial infarction within one hour of use, and cardiovascular events have been reported in otherwise healthy patients. 

A Norwegian autopsy study suspected THC-induced arrhythmias as the culprit in six patients who died suddenly.  Electrocardiograms should be obtained for patients with severe cannabis intoxication; telemetry monitoring may be considered for patients with known cardiac pathology. Electrolyte abnormalities reported in marijuana users contribute to this cardiac pathology. Chronic marijuana users have lower serum sodium and potassium than non-users. The heavy consumption of carbohydrates while intoxicated leads to an increase in serum insulin levels, driving potassium into cells and causing serum hypokalemia. This hypokalemia can produce reentrant arrhythmias by decreasing conductivity and increasing the resting membrane potential, duration of the action potential, and duration of the refractory period. EKG changes include the decrease in T-wave amplitude, presence of U waves and a prolonged QTc. This patient’s very high THC metabolite level, prolonged QTc, and hypokalemia increased her risk for an arrhythmia. The hypokalemia observed in this case was likely related to acute intracellular potassium shifts superimposed on chronic hypokalemia. Clinicians must manage other, non-vascular risks of acute marijuana use. Respiratory symptoms include shortness of breath, wheezing, and even respiratory failure when marijuana has been smoked “wet” with phenylcyclidine or embalming fluid. Patients with pre-disposing genetic vulnerabilities may develop hypokalemic periodic paralysis. And, marijuana use correlates with fatal motor vehicle collisions – clinicians should educate patients and ensure a safe transportation plan on discharge. Patients with toxic ingestion must be screened for coingestion. The persistence and intensity of the patient’s symptoms warranted consideration of multiple involved substances. Co-ingestion may also be signaled by an abnormal osmolar or anion gap, air racking positive urine toxicology screen, or QTc or QRS prolongation . However, in many cases, the presence of co-ingestion may only be detected once the patient is able to provide a reliable history. In this case, an elevated B12 level was found on work up of the patient’s psychiatric symptoms and suspected to have been caused by energy drink consumption; only later did the patient confirm this suspicion. By its effects on mesolimbic dopamine activity, caffeine may precipitate psychosis, exacerbate chronic psychosis, or worsen affective lability and mood states. This patient’s high THC metabolite level and medical course are consistent with cannabis psychosis; however, we cannot exclude excessive caffeine use as a contributor to this presentation. What is this patient’s prognosis? Marijuana correlates with the onset of psychosis in patients with schizophrenia and perhaps bipolar disorder as well. About half of patients with cannabis psychosis will later be diagnosed with a primary psychotic disorder. This high rate may reflect high rates of marijuana use among patients with schizophrenia. Younger age, greater frequency of marijuana use, family history of psychosis, trauma history, and schizotypal personality correlate with higher risk of a later diagnosis of primary psychosis. ED providers can mitigate the risk of psychopathology by addressing the patient’s substance use disorder. Safe detoxification is a primary goal and was accomplished here; brief interventions like motivational interviewing and referral for treatment in the ED may reduce use on discharge. Cannabis is an adaptive and highly successful annual with the ability to grow in most climates across the globe. Cannabis belongs to the Cannabaceae family, “has a life cycle of only three to five months and germinates within six days.” Cannabis can occur in a wild, reproducing state throughout the California floristic provinces, and is cultivated even outside of areas where it may naturally reproduce. 

Cannabis planting, growing, and harvesting seasons are similar throughout California and typically take place April through October. “Exposed river banks, meadows, and agricultural lands are ideal habitats for Cannabis” since these ecosystems provide “an open sunny environment, light well-drained composted soil,and ample irrigation.” The Cannabis plant has been utilized to produce a diverse set of products with various applications. Today, Cannabis is most commonly produced for its psychoactive properties, though historically it has been used for agricultural production, nutritional value, and industrial purposes. The two species of Cannabis cultivated for psychoactive and physiological effects are Cannabis sativa and Cannabis indica. Marijuana is the most common name referring to varieties of Cannabis produced for mind altering affects. Marijuana contains high levels of chemical cannabinoid compounds including delta-9 tetrahydracannabinol, or THC, the primary psychoactive component of Cannabis. Cannabis has a long history of use in the United States. During the 17th century, the government encouraged hemp production, a fibrous form of Cannabis, for use as rope, clothing, and sails. In the early 20th century after the Mexican Revolution, the recreational use of marijuana was introduced by Mexican immigrants. In 1937, the Marijuana Tax Act was enacted to effectively criminalize marijuana consumption as a result of an anti-marijuana propaganda campaign led by the commissioner of the Federal Bureau of Narcotics, Harry J. Anslinger. During World War II the U.S. Department of Agriculture provided incentives, including draft deferment, for farmers to grow hemp to meet wartime fiber needs. In the 1950s, a series of federal laws were enacted to create mandatory sentencing for people convicted of using drugs classified as illegal, including marijuana. Despite stricter regulation, marijuana was embraced by popular counter-culture movements in the 1960s. This act classified marijuana as a Schedule I controlled substance, the most restrictive schedule of illegal drugs “found by the government to have a high abuse potential, a lack of accepted safety under medical supervision, and no currently accepted medical use.” In fact, the whole Cannabis plant was classified as Schedule I, which means that possession of any portion of the Cannabis plant became illegal under federal law. Petitions to reclassify Cannabis have been proposed since the 1970s based on an ever increasing literature of clinical studies and scientific research that disputes the vague classifications of “high abuse potential, a lack of accepted safety under medical supervision and no currently accepted medical use.” This article of the Comprehensive Drug Abuse Prevention and Control Act was brought to the forefront of legal and political debate in 1996 when the Compassionate Use Act, or Proposition 215, passed in California, followed by 13 other states, to legalize the medical use of marijuana. Criteria for the legal possession of medical marijuana vary from the state to county levels, but Cannabis possession and consumption remain illegal at the federal level. In the pivotal Supreme Court decision of Gonzales v. Raich, the court ruled that the federal ban on cannabis may be enforced at all levels of jurisdiction based on the Commerce Clause of the United States Constitution. Their basis was that “incidents of the traffic which are not an integral part of the interstate or foreign flow, such as manufacture, local distribution, and possession, nonetheless have a substantial and direct effect upon interstate commerce.” Despite the precedent set by this case, the development of legalized medical marijuana has led to significant changes in domestic Cannabis cultivation. In California, marijuana is cultivated in various amounts ranging from a single plant grown for personal consumption to thousands of plants per plot cultivated for commercial distribution.

However, rather than precipitating the global circulation of new models of cannabis-liberalization reform, this early crisis stimulated new cycles of recursive transnational lawmaking, leading to the entrenchment of the prohibitionist approach. In the US, calls to reintroduce tougher drug laws resonated with the wider conservative offensive against the putative “soft on crime” inclinations of liberal policymakers in the post-civil rights era. Opponents of legalization sought to challenge the public health frame that gained increasing influence in the wake of the Shafer Commission’s Report and to contextualize the issue of cannabis use as yet another symptom of a putative law and order crisis in American cities. The proliferation of grassroots parents’ movements lobbying for the stricter regulation of marijuana provided considerable political momentum for the introduction of tougher penalties for trafficking and possession offenses. The process by which cannabis prohibition norms again became settled at the national level in the US provided facilitative conditions for the increasing involvement of the federal government in exporting its drug policies to other countries. This effort became increasingly consequential in an historical moment in which the US came to perceive itself “not just as a powerful state operating in a world of anarchy” but as “a producer of world order.” With the end of the Cold War, new discourses of “securitization” emerged as part of the search for a new way of grounding America’s internationalist engagement. Drug policy became increasingly aligned with national security issues pertaining to the activities of insurgent and terrorist groups in Latin American countries and to the risks posed by these groups to the democratic stability and peace in the region.

This new frame of diagnosing the implications of the illegal drug trade led to the development of new modes of defining the goals of US counternarcotic policies as well as the strategies through which such goals should be pursued. These new strategies have sought to reduce drug production at the source, to combat drug trafficking en route to US borders, dry racking to dismantle international illicit drug networks, to reduce drug demand at home and abroad, and to incentivize foreign governments to cooperate with US counternarcotic goals. The institutionalization of these strategies necessitated strengthening the capacity of the US government to influence the drug policies of other countries and to dominate the transnational agenda of cannabis control. From the mid-1980s onwards, the US government institutionalized an array of multilateral, bilateral, and unilateral measures intended to coerce, induce, and socialize other countries to cooperate with its counternarcotic strategies. Its multilateral efforts have largely been based on the extensive funding and support of international and regional organizations that are committed to the prohibitionist approach. In this context, the US has consistently pushed for an expansion of the International Narcotic Control Board’s monitoring authority and has served as a staunchest defender of its prohibitionist policies.38Building on and expanding the scope of the international obligations enshrined in the Vienna Convention and the INCB recommendations, the US has made extensive use of bilateral treaties to create an issue-linkage between states’ willingness to adopt zero-tolerance models of drug policy and their eligibility for foreign aid. Over the next decades, such bilateral agreements provided a basis for the operation of extensive cooperation and capacity-building projects in countries as diverse as Afghanistan, Colombia, Mexico, Nigeria, Peru, Ghana, Thailand, and many others. Along with these multilateral and bilateral instruments used to influence the drug policies of other countries, the US government has had an extensive reliance on unilateral tools of imposing economic and reputational sanctions on non-compliant states. In 1986, Congress introduced the Omnibus Drug Enforcement, Education, and Control Act, which created a certification process fordrug-producing and drug-transit countries. 

The certification process requires the president to withdraw financial assistance and support in multilateral lending institutions from countries that fail to comply with requisite benchmarks of antidrug policy. To enable congressional deliberations over such sanctions, the US Department of State submits an annual International Narcotic Control Strategy Report that identifies the major illicit drug-producing and drug-transit countries and evaluates the extent to which their domestic policies are in compliance with the US counternarcotic agenda. The INCSR narrative explores a wide range of countries . The certification process is applied to countries included in what came to be known as the Majors List . The success of the US to coerce and to induce dozens of countries to adopt its preferred models of implementing cannabis prohibitions promoted convergence of drug laws across jurisdictions and thus increased the degree of concordance between the transnational and the national levels of this TLO. However, the global diffusion of tougher cannabis laws cannot be sufficiently explained by focusing on the coercive mechanisms employed by the US alone. This diffusion was also a product of broader social transformations stimulating increasing political mobilization around law and order issues during the final decades of the twentieth century. Illustrating Durkheim’s observation that societies have a functional need to construct categories of deviance, the instigation of moral panics concerning drug abuse epidemics provide a useful tool of identifying “suitable enemies” and scoring political points. In an era during which a broader shift from welfare oriented to punitive-focused approaches to governing social marginality took place, strengthening state capacities to condemn and to penalize drug dealers and users proved to be a far more attractive project for politicians than undertaking to address the public health implications of drug use.

As the primary international organization responsible for monitoring the implementation of the UN drug conventions, the INCB played an important role in facilitating the concordance between the transnational and national levels of the cannabis prohibition TLO. In its annual reports, the INCB has repeatedly supported the “gateway drug thesis,” according to which the use of cannabis serves as a risk factor in increasing the user’s probability of using harder illicit substances, such as amphetamine, cocaine, or heroin. Based on this thesis , the Board’s 1983 Report criticized those “circles in certain countries” that “apparently assume that to permit unrestricted use of some drug, regarded by them as less harmful, would permit better control of other drugs which they deem more perilous to health.” This criticism was leveled at supporters of the separation of markets strategy, which came to be endorsed by Dutch policymakers at the time. In its later reports throughout the 1980s and 90s, the Board adopted an increasingly critical stance toward the Dutch attempts to depenalize cannabis usage. In its 1997 Report, the selling of cannabis in coffee shops was depicted as “an activity that might be described as indirect incitement.” The focus on the Netherlands and its singling out for disapprobation reflects the rarity of open contestations of the prohibitionist imperatives enforced by the Board during that period.The extensive institutionalization of the cannabis prohibition TLO throughout the 1980s and 1990s facilitated the international spread of tougher laws, severer penalties, and more aggressive policing strategies. However, the very success of this TLO to propagate its policy models highlighted its failure to deliver on its own promise to reduce the prevalence of cannabis use and to eliminate its illicit supply chains. The intensification of enforcement activities also brought into focus the adverse human rights impacts of implementing the prohibitionist cannabis policies. The increasing criticisms of the failures and boomerang effects of the cannabis prohibition TLO prompted both internal and external processes that eroded its legitimacy and compromised its ability to continue guiding the practices of legal actors at the national and local levels. From the early stages of the institutionalization of the cannabis prohibition TLO, it became vulnerable to criticism of its inherent input legitimacy deficiencies. As discussed earlier, the central role played by the US in shaping the goals and strategies of this TLO has largely depended on the exercise of unilateral measures of coercion and inducement. The degree to which the certification process has realized basic standards of transparency, inclusiveness, cannabis curing and accountability is obviously limited. The procedures by which the INCB defines and applies its compliance criteria seem conspicuously insulated from ongoing public debates regarding the impact of cannabis prohibition laws on marginalized populations. These legitimacy deficits are conveniently set aside by proponents of the war on drugs, who tend to focus more on the ability of these measures to promote global public goods than on the quality of the processes through which these measures are created.

As Niko Krisch observes, such tendency to prioritize output legitimacy considerations is pronounced in various contexts of global governance and often produces pressure to move toward more informal and hierarchical modes of transnational governance in these issue-areas. However, this view is becoming increasingly difficult to maintain in the issue-area of cannabis policy given the mounting evidence on the failure of this TLO to achieve its regulatory goals. Despite billions of dollars of investment and extensive law enforcement resources, a sizable body of scholarship has documented the growing availability of the drug during the 1990s, the widespread prevalence of its usage among adolescents, and the increasingly tolerant attitudes toward cannabis consumption among both users and non-users. Drawing analogies to the failure of the “Noble Experiment” of the alcohol prohibition period, criminologists developed thorough critiques of the underlying assumptions of the cannabis prohibition TLO. The assumption that the availability of cannabis can be meaningfully reduced by the deployment of militarized policing strategies has been criticized for overlooking the resilience of cannabis markets and their high levels of adaptability to changes in their regulatory environments. Studies have shown that rather than eliminating supply chains, such interventions served to disperse, displace, and fragment supply sources and distribution routes. In turn, such interventions precipitated a spillover of armed violence to new geographical areas and exposed otherwise uninvolved indigenous populations to new risks and insecurities. The inherent flaws of this dimension of the cannabis prohibition TLO are often illustrated by referencing the “balloon effect” metaphor, depicting the ways in which efforts to suppress the cultivation of cannabis in one geographical area causes a convenient shift of its production elsewhere. The legitimacy of the cannabis prohibition TLO has also been damaged by evidence regarding the immense human rights violations that the implementation of war on drugs policies has entailed. Advocacy networks led by prominent transnational NGOs, such as Amnesty International and Human Rights Watch, have exposed the disproportionate punishments imposed under the banner of the war on drugs in various countries. In the US, such criticism focused on the contribution of marijuana prohibitions to the nation’s internationally unparalleled incarceration rates and its distinctive patterns of racially-skewed law enforcement. A recent ACLU report using data extracted from the FBI’s Uniform Crime Reporting Program indicates that between 2001 and 2010, there were over eight million marijuana arrests in the US, of which 88% were for marijuana possession. In 2010, there were more than 20,000 people incarcerated for the sole charge of cannabis possession. Outside of the US, human rights activists focused on the increasing use of capital punishments for drug offenses from the late 1980s onward, as part of the broader escalation of enforcement efforts during the war on drugs era. In China, Saudi Arabia, and the Philippines, the death penalty is exercised regularly for cannabis trafficking offenses. By the mid-1990s, the criticism leveled at the cannabis prohibition TLO began to stimulate increasing advocacy activity in favor of reform. These activities failed to change the direction of drug policy making at the international level. Indeed, the “outcome document” issued in the wake of the 2016 UN General Assembly Special Session on drugs kept in place the existing framework of cannabis prohibition and did not endorse the calls to reclassify cannabis as a less dangerous drug. However, the criticism of the prohibitionist approach had a considerable transformative impact on the development of drug policies at the national and subnational levels. Before long, the diffusion of liberal cannabis policies across national borders began to jeopardize the normative settlements institutionalized by the cannabis prohibition TLO in previous decades. The efforts to liberalize cannabis regulations have focused on three distinct models of reform: depenalization, decriminalization, and legalization. Under formal depenalization regimes, the possession of cannabis is still formally prohibited; however, such prohibitions are enforced through intermediate justice measures rather than through conventional penal sanctions such as incarceration.

Physical activity was assessed using self-report to several questions . For the physical activity variable, subjects were classified as inactive if they did not report engaging in any of the following activities during the previous month: walking, jogging, bike riding, swimming, aerobics, dancing, calisthenics, gardening, lifting weights or other physical activity outside their occupation. Individuals were considered to fulfil national recommendations for physical activity if they reported five or more episodesper week of moderate-intensity physical activity or three or more episodes per week of vigorous-intensity physical activity.Descriptive statistics were used to characterise the subjects . To test the statistical difference between the groups, we used c2 test for categorical variables and two-sided t tests for continuous variables. A p value of <0.05 was considered significant. Univariate and multivariate logistic regression analyses were used to determine the relationship between DM and marijuana use. We used multivariate logistic regression to adjust for confounding variables and reported the OR and the 95% CI. Variables considered as possible confounders in the multivariate analysis were age, gender, race/ ethnicity, BMI, education level, cigarette smoking, alcohol use, physical activity, serum total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, vitamin D, CRP, ferritin, fibrinogen, WBC count and uric acid. In order to confirm that marijuana use was associated with DM and not due to confounders, we analysed how each potential confounder changed the OR of having DM. Variables that changed the OR by $10% were considered as confounders and included in the multivariate model. We performed stratified analysis to test for effect modification. For effect modifier variable, multivariate logistic regression model was constructed for each subgroup. In addition, to help adjust for selection bias, we analysed the data using the propensity score matching and estimated the average treatment effect for the treated, cannabis racks bootstrap SE and t statistics. We added the propensity score to the logistic regression model as inverse weight, blocks that satisfy the balancing property and quartiles.

Data were analysed using SAS and the survey module of STATA . Sample weights, provided by the National Center for Health Statistics, were used to correct for differential selection probabilities and to adjust for non-coverage and non-response.13Our analyses of adults aged 20e59 years in the NHANES III database showed that participants who used marijuana had lower prevalence of DM and had lower odds of DM relative to non-marijuana users. We did not find an association between the use of marijuana and other chronic diseases, such as hypertension, stroke, myocardial infarction and heart failure. This could be due to the smaller prevalence of stroke, myocardial infarction and heart failure in the examined age group. We noted the lowest prevalence of DM in current light marijuana users, with current heavy marijuana users and past users also having a lower prevalence of DM than non-marijuana users. The finding that past marijuana users had lower odds of prevalent DM than non-users suggests that early exposure to marijuana may affect the development of DM and a window of time of marijuana exposure earlier in life could be a factor to study. Similarly, our findings of a significant association between marijuana use and DM was only found in those aged $40 years suggest that the possibility of some protection from marijuana use may require many years before they become manifested. By contrast, it could reflect the increased prevalence of DM with age and the ability to detect an association with a lesser sample size when there is a greater cohort at risk for DM. The possible association of light marijuana use with decreased DM is similar to that of alcohol on DM and the metabolic syndrome, in which mild alcohol use was associated with lower prevalence of DM and the metabolic syndrome, and higher alcohol use associated with higher prevalence of DM and the metabolic syndrome. Smit and Crespo9 used the NHANES III population to examine dietary factors of non-marijuana users and marijuana users among adults aged 20e59 years. Similar to our data, they found that 45% reported used marijuana in their lifetime and 8.7% used marijuana in the past month.

Current marijuana users had higher intakes of energy and nutrients and consumed more soft drinks but had slightly lower BMI than non-current marijuana users. Thus, it is unlikely that a healthier diet contributed to the decreased prevalence of DM among marijuana users found in our study. In our study, all marijuana users had lower BMI than non-users, with heavy marijuana users having the lowest BMI. The lower BMI may be protective for DM, although when we controlled for BMI, the prevalence of DM was not significantly changed suggesting additional BMI-independent pathways. Smit and Crespo9 did not record glycaemic parameters or prevalence of DM. Using NHANES III data, marijuana users had lower rates of obesity and lower mean BMI, with current heavy marijuana users having the lowest BMI, in agreement with a recent report using National Epidemiologic Survey on Alcohol and the National Comorbidity Surveye Replication databases. Correcting for the effect of BMI, the association between marijuana use and DM was reduced by 17% but remained highly significant. We postulate that the decreased prevalence of DM and marijuana use may be due to the anti-inflammatory properties of marijuana. CBs found in marijuana favourably modify inflammation probably through the inhibitory actions on prostaglandins and COX-2.18 Hu and colleagues reported that CRP, but not interleukin-6 and tumour necrosis factor-a receptor-2, was associated with the risk of developing DM. In our study, serum level of CRP, fibrinogen ferritin, uric acid and WBC counts revealed varied associations with marijuana use. Of note, the CRP assay used in NHANES III was not a highly sensitive assay and is unlikely to pick up small changes in an inflammatory state in a single individual; however, it is still a robust measure of inflammation and is useful in population studies. However, we did find a U-shaped association between the CRP levels and marijuana use groups. Rodent studies using CBs have shown significant benefits against diabetic complications and atherosclerosis.19 20 Additionally, lower doses of CBs appear to be anti-inflammatory in rodents.19 CBs, including the non-psychoactive cannabidiol, have also been shown to attenuate progression of type 1 DM in animal models. We have not identified any study in human subjects or animals examining marijuana or its active ingredients and the incidence of type 2 DM, although one study found similar glucose levels in marijuana users as non-users.8 In a prospective study using a cannabis based medicinal extract compared to placebo to treat diabetic neuropathy, glycaemic indices were not mentioned. We examined physical activity in patients using marijuana and found that it did not confound the association between marijuana and DM. Although the CB1 antagonist, rimonabant has been used successfully to treat DM, we are not surprisedat the association between marijuana use and decreased prevalence of DM. Marijuana contains a variety of CBs, of which some, such as cannabidiol and delta9- tetrahydrocannabivarin, have antagonist properties that may mediate the anti-inflammatory properties of marijuana.

A limitation of our study was its cross-sectional nature. Despite the efforts of NHANES to enrol a random representative sample of the US population, persons attending the study visits may differ from those not attending in subtle ways that may affect the results of this study. We are unable to conclude that marijuana use does not lead to DM nor do we suggest that marijuana should be a treatment for DM. Although we controlled for major confounders, it is possible that non-marijuana users and subjects with DM share some, as yet unknown, cannabis drying rack ideas characteristic accounting for the relationship between DM and non-marijuana use. An additional limitation is that the marijuana use was based on self-report and self-report of illicit substances is often underestimated on self-reports. Self-report is subjected to recall bias. However, we expect that recall bias would be similar in those with DM as those without DM and would be unlikely to bias our results. Although current marijuana users were divided into heavy and light users based on the number of times they reported using marijuana per month, the amount of marijuana consumed, route of consumption , duration of use and time when they quit were not reported. A potential limitation was that most patients with DM were identified by self-report, with a smaller number of patients identified by having an elevated fasting blood glucose levels. Because some patients with DM receiving treatment are euglycaemic, blood glucose levels alone cannot be used to identify those patients with DM. However, the percentage of marijuana user was similar in those patients with DM identified by self-report as that of those with DM identified by fasting glucose testing. While we analysed all patients with DM together, we estimated that over 98% of the patients had type 2 DM, and therefore, our results are likely to apply only to patients with type 2 DM. Another limitation is the possibility of a cohort effect since those who use marijuana may have other factors that may predispose decreased prevalence of diabetes compared to non-users besides lower BMI. In conclusion, marijuana use was associated with a decreased prevalence of DM. Prospective studies in rodents and humans are needed to determine a potential causal relationship between cannabinoid receptor activation and DM. Until those studies are performed, we do not advocate the use of marijuana in patients at risk for DM.Marijuana is the most commonly used “illicit” drug in the U.S. with approximately 12 million people over age 12 reporting past month use , and marijuana use disorder nearly doubling from 2001– 2002 to 2012–2013 . The addictiveness of marijuana continues to be debated as the landscape regarding marijuana legalization changes , but the evidence largely indicates that excessive use can lead to adverse consequences and diagnoses of MUD . In 2014, 4.1 million people 12 years of age or older met the DSM-IV criteria for MUD nationally . In addition, most people who develop MUD have comorbid conditions that can worsen prognosis and contribute to poor health outcomes . Regular and heavy marijuana use is associated with increased risk of anxiety, depression, and psychoses, although causality has not been established . In addition, heavy use, high potency, and exposure at younger ages can all negatively affect the course of mental illness . Marijuana use among adolescents also predicts increased risk of MUD in adulthood , which, in turn predicts, high risk of other drug use and escalation to co-occurring substance use disorder . Marijuana frequently is used by persons who drink in excess and use other illicit drugs , which compounds risk to health and safety. Marijuana is associated with increased risk of several medical conditions. Regular and heavy marijuana use can contribute to respiratory deficits such as airway resistance, large airway inflammation, lung hyperinflation, and can lead to chronic bronchitis . Marijuana use is also related to a high risk of respiratory infections and pneumonia , vascular conditions that raise the risk of cardio/ cerebrovascular events, such as stroke and myocardial infarction , and an increased risk of lung and digestive track cancers . Not surprisingly, these medical conditions are even more prominent among those with MUDs and contribute considerably to the burden of disease . Marijuana has also been associated with increased risk of motor vehicle accidents, and other acute health events . Despite the adverse health effects of MUD, few studies have examined the relationship of MUD to emergency and inpatient service utilization. These are among the most costly health services, and may indicate inappropriate use of health care and/or unmet need. The few studies in this area have focused on any marijuana use rather than on higher severity users with MUD; although MUD patients are likely at the highest risk for utilizing ED and inpatient resources, given the disorder’s consistent association with adverse outcomes and poor health. One recent study found marijuana, either used alone or in combination with other drugs, is often reported by those who have ED visits, and this number has increased over the past decade . Results are mixed regarding the effect of substance use on inpatient use ; and one study found no evidence of an association between frequency of marijuana use and hospital admissions . The degree to which such findings are specific to marijuana use or persist over time in persons with MUD, who likely have more complex clinical presentation and service needs than those with subdiagnostic use, is largely unknown. This study addresses this important question by examining emergency and hospitalization utilization trends and trajectories in a large sample of 2,752 patients with MUD and 2,752 healthy controls in a large integrated health care system.

Participants who felt that they did not look or act like members of their racial/ethnic group demonstrated increased odds of marijuana use. Young adults who feel marginalized by family members or friends may seek to find a way to belong and connect with other young adults and marijuana use may be a way to find belonging within a group. This parallels research, which suggests that the decision to engage in marijuana use comes from an internal need for emotional connection and friendship and as an opportunity to connect and create a sense of belonging . Other research has identified marijuana as a more acceptable substance viewed as superior and safer than other substances . Marijuana may be the substance of choice to build connection with others and combat feelings of intragroup marginalization. If marijuana use is perceived as a means for social connection, it may help to explain the findings between Factor 1 and cigar use. When controlling for demographic characteristics, participants who felt as though they did not look or act like members of their racial/ethnic group had decreased odds of cigar use. Cigars were the least frequently used product within the sample retained for analysis.National averages parallel this trend with current cigar use having lower prevalence than to cigarettes and marijuana for young adults .If marginalized young adults seek to connect with others via substance use, cigar use may not be the best mechanism by which to connect with others and therefore they may be less likely to use cigars. The combination of low rates of use and potential lack of opportunity to build social connection may help explain the decreased odds of cigar use. This finding is unexpected and further research is needed to better understand the relationship between intragroup marginalization and cigar use. Similarly, cigarette, e-cigarette, blunt use, pipp racking system and hookah use had lower rates compared to marijuana use. While unexpected, cigarette, e-cigarette, and blunt use were not associated with experiences of intragroup marginalization.This may be due in part to the lower rates of use.

It is worth noting that blunt use was examined independently, although it is often associated with marijuana use and in this sample most blunt users also reported concurrent marijuana use .Additionally, the use of these substances may be less tied to social use and therefore their use may not be linked to developing ways of belonging. Past research has differentiated between ‘social smoking’ and smoking alone . Studies have suggested that young adults not in college may be less likely to be social smokers and social smoking may not be prevalent across racial/ethnic groups .This study did not differentiate between social smoking and smoking alone and may be another important factor to better understand the role of intragroup marginalization and tobacco use. Intragroup marginalization was associated with higher hookah use; however, when controlling for race/ethnicity this association was no longer significant due to racial/ethnic differences. While hookah use has been noted as a means for socializing and is often smoked in a group setting , this may be population specific. Hookah use is common in Middle Eastern countries and has strong cultural underpinnings . Middle Eastern young adults experiencing intragroup marginalization may use hookah as a means to connect and fit in within their cultural group. Furthermore, African Americans have been found to have lower rates of use compared to other ethnic/racial groups . Additional research may be needed to further investigate differential impacts of intragroup marginalization on hookah use ethnic/racial group. Factor 1 captures the challenges young adults face when they feel they do not fit in with members of their ethnic/racial group. While Factor 1 focuses on difficulties in belonging and membership, Factor 2 centered on shared values and dreams. Feeling marginalized due to a lack of similar hopes and dreams was not associated with tobacco or marijuana use. This finding supports the theory that young adults use these substances as a means of building belonging and connection . While having dissimilar hopes and dreams may be stressful, it may not necessarily indicate one does have any connection to others.

Given these findings, the scale may be able to be further abbreviated by dropping Factor 2, particular when examining tobacco and marijuana use. Future research may be needed to further investigate impacts of Factor 2 on other health outcomes. Despite the strengths of this research, there are important limitations to note.This study focused on young adults in the San Francisco Bay Area, and findings may be not be generalizable to all young adults. However by using population-based sampling, we were able to obtain a representative sample, which past research has noted the difficulty in reaching urban young adults . This study also utilized a cross-sectional design, preventing any potential inference concerning causality. Tobacco and marijuana use were measured using self-report data and use was not biochemically verified. While past research has demonstrated the reliability and validity of self-reported smoking in anonymous surveys with young adults this validation has not extended to non-cigarette tobacco products;this may be a potential area for future research. This study examined intragroup marginalization among Mixed Race young adults; a population often overlooked in intragroup marginalization studies. Mixed Race participants were not required to identify which group served as the primary source of intragroup marginalization. However, it is possible that different cultural norms around tobacco and marijuana use could influence whether intragroup marginalization impacted behavior. Oyserman and colleagues have demonstrated the identity-based motivation of health behaviors, with racial/ ethnic minorities more likely to identify unhealthy behaviors with their group. Additional research may be needed with Mixed Race individuals to better understand how different groups may impact the relationships between intragroup marginalization and tobacco use. A final limitation is that we did not directly assess reasons or motivations for use. Future qualitative research is needed to explicitly examine motivations for use as a result of experiences of intragroup marginalization. This study provides the first quantitative examination of intragroup marginalization with tobacco and marijuana use. Results respond to recent calls to better understand motivations for young adult marijuana use , with findings demonstrating an association between intragroup marginalization and increased marijuana use.These findings are especially relevant given the changing climate regarding the legalization of marijuana, with California just recently voting to legalize marijuana . Results reaffirm existing arguments that drug policy must attend to the social and cultural contexts of use Additionally, findings respond to existing calls in the literature to better understand how culture impacts use . Past intervention research has highlighted the importance of attending to peer smoking behavior and norms, providing further support for the need to attend to social dynamics when addressing young adult tobacco and marijuana use . Additional research is needed to further investigate the relationship between intragroup marginalization and marijuana use, which can help in the tailoring and development of targeted health education programs.The period from middle school to high school is associated with important developmental changes that occur physically, socially and mentally . Initiation of alcohol and/or marijuana during this time period can significantly affect functioning, especially if youth initiate at a younger age. For example, AM use during this time period is associated with academic problems, poorer mental health, use of other illicit drugs in the future , and a higher likelihood of abuse or dependence in adulthood . Furthermore, given that the brain is still developing, adolescents can still have memory, attention, and reaction time deficits even after they stop using compared to youth who have never used AM . Studies in the United States examining trajectories of alcohol use during adolescence have shown a consistent pattern.

Initiation typically occurs in early adolescence , with drinking rates increasing steadily during mid- and late adolescence before peaking in early young adulthood . Marijuana use trajectories follow a similar pattern, albeit with a later average age of initiation . However, pipp vertical racks not all individuals follow this general pattern; thus research has focused on identifying distinct developmental trajectories of AM use. Most of these studies identify a group of persistent or high users, a declining group where use starts off heavy and gradually declines over time, an increasing group where use gradually escalates over time, and a moderate/infrequent group that uses occasionally over time . Persistent or high AM users typically have the worst outcomes . For example, youth in high marijuana use groups during high school also reported higher rates of both mental health and drug problems at age 21 ; membership in higher alcohol use groups in 6th grade was associated with greater use of other substances and violent behavior in 8th grade ; youth in the heaviest drinking trajectory group at age 18 had more problems with verbal memory and monitoring two years later ; and youth who initiated alcohol and cigarettes concurrently early on reported worse physical health, a higher likelihood of selling drugs and the highest rates of self-reported problems compared to groups that did not initiate use in early adolescence . Few studies have examined trajectories of alcohol and other drug use among diverse ethnic and racial samples across middle school and high school . However, the face of the United States is changing. During the next 15 years, Asian American, Hispanic American, African American, and Native American populations are expected to rapidly grow in size, with each of these cultures subsequently comprising a significant proportion of the nation . In addition, multi-racial Americans are the fastest growing population under age 18 . Research has shown that non-Whites often have worse health outcomes and more interpersonal problems and other negative outcomes from AOD use compared to Whites, even with less AOD use. To date, there are no studies that longitudinally address when these disparities may start; for example, whether we may see disparities in functioning due to AOD use begin as early as adolescence. It is imperative that we assess when disparities in functioning may begin to occur and in what domains so that clinicians and providers can better determine the best time and way to intervene. A small body of research has assessed racial/ethnic differences in AOD use; however, studies typically focus on one substance and do not address potential disparities in outcomes. Results indicate that Whites and Hispanics are more likely than Blacks and Asians to drink alcohol , smoke cigarettes , and use marijuana . Four recent studies have examined racial/ethnic differences in more than one substance across adolescence into adulthood . They all used data from the National Longitudinal Study of Adolescents and Adults to examine use of cigarettes, alcohol, and marijuana. Although these studies examined use from adolescence to adulthood, they only had four waves of data that were spaced over a 14 year period. Setoh and colleagues examined differences between Whites and Hispanics; Keyes et al. compared Whites and Blacks; Chen and Jacobson compared Whites, Blacks, Hispanics and Asians; and Evans-Polce et al. examined differences between Whites, Hispanics and Blacks. Three studies found that White youth had higher rates of AOD use initially and increased their use more rapidly over time than non-White youth; however, racial/ethnic differences lessened as youth aged indicating that non-White youth “caught up” in their 20’s and 30’s. Chen and Jacobson found that Hispanics had the highest rate of use for all substances at age 12, with Whites increasing the most rapidly, and peak levels of use for Blacks occurring at later ages. These studies have significantly advanced our knowledge in this area; however, several gaps need to be addressed. First, few longitudinal studies examine trajectories for more than one substance. Given that AM are the two substances initiated and used most frequently during adolescence, it is important to examine how trajectories of AM use during this time period may differentially affect outcomes. Second, none of these studies measure AM use with regular assessments during both middle school and high school. These are important developmental time periods to measure consistently. More regular assessments allow examination across critical transitions, including from age 11 to 14 when use rates increase dramatically , and from 14 to 17 when youth begin to gain more independence from parents and may have more opportunities to engage in risk behaviors . Third, studies tend to focus on differences between just a few racial/ethnic groups.

Some of these factors were also supported in previous research examining parental perceptions and beliefs of marijuana use and discussions with their children , and now could extend to include unhealthy eating discussions as well. By addressing these constructs, we were able to propose an adapted theoretical model that could possibly decrease unhealthy eating and marijuana use in children and adolescents. According to descriptive analyses, a good proportion of parents had trouble engaging in discussions with their children centered on unhealthy eating and marijuana use . As a result, this project further proposed and developed three parenting framed messages aimed at promoting parent and child discussion of the health risk behaviors . The authoritative parenting-framed message was rated as most effective in motivating discussions about unhealthy eating and marijuana use compared to authoritarian parenting-framed message and permissive parenting-framed message. Relatedly, several studies have found that authoritative parenting styles are associated with decreased health risk behaviors in adolescents, including lower use of alcohol, tobacco, and illicit drugs . These conclusions were utilized to develop discussion tools that included the authoritatively-framed message, in order to further motivate effective discussions about unhealthy eating and marijuana use between parents and their children . It is believed that parents who struggle to have these discussions might benefit from tools on how to have these conversations with their children.The study findings partially supported the moderating effects of parenting styles on discussion tools and some of the cognitive factors. Future studies could target the implementation of additional discussion tools, aside from unhealthy eating and marijuana use discussion tools.

This could gather information on ways to improve the utility of the authoritative parenting-framed message within the context of the discussion tool by closely examining the effects on several health-risk behaviors. It could be that some behaviors respond better to the authoritative parenting component compared to others. Although, vertical air solutions these tools were still effective in motivating discussions, and so, the discussion tools could be modified and tested in a bigger sample.Limitations of the present research project requires consideration when interpreting the results and point to directions for future research. Initially, the results may not be representative of all parents across the nation or in other countries, as Study 1 and 3 consisted predominantly of Non-Hispanic White and well-educated participants, whereas Study 2 consisted of participants between the ages of 18 to 20 years old. More research is needed to measure the practicality of the discussion tools with more ethnically diverse groups. With regards to marijuana use, utilizing random samples of parents in the United States could prove to be beneficial in interpreting results, as the landscape is constantly changing with regards to marijuana legalization laws, and could impact discussion of marijuana use between parents and their children. Another important limitation to consider is the lack of fathers within the samples. Fathers may have differing responses to the discussion tools compared to mothers. As noted by the participant characteristics , the parents were primarily mothers of children ages 10 to 17 years old and 80% of responses by children were about their mothers . It warrants the need to investigate the impact of perceived parenting styles of fathers on motivating discussion of unhealthy eating and marijuana use. The comparability of responses across mothers and fathers could lead to the incorporation of richer parenting practices to consider when designing future discussion tools. Moreover, all three studies relied on self-report on specific questions, which may lead to bias of participant responses.

The partial support of the moderating effects of parenting styles indicates the need for further investigation of how these practices could influence discussion outcomes, and copiously recognize the implications in promoting future discussions about unhealthy eating and marijuana use. Additional studies of parents of children in younger age groups , and children of younger age groups are needed. This could provide more information on what elements are most effective when designing discussion tools for varying child age groups, and if differences exist. The present research project provided preliminary findings to consider on the moderating effects of authoritative, authoritarian, and permissive parenting styles, and could be expanded to include additional traits and temperaments specific to parents and children. It may be beneficial to measure more acceptability items after participants view the discussion tools, by including more items than perceived effectiveness, perceived interpretability, motivations to address the behavior after the discussion tools, in order to provide additional ways of testing the effectiveness of the tools. This could possibly elicit richer qualitative data onthe differing effects of the discussion tools on parents and their children. By identifying key words and phrases that were utilized in their discussions, it could lead to the consideration of other parent-child practices or characteristics that could influence the discussions of these behaviors.To conclude, the present research project explored the associations of a revised theoretical framework of parenting styles and PWM factors on parent motivations to discuss unhealthy eating and marijuana use with their child , tested the acceptability of authoritative parenting-framed messages of unhealthy eating and marijuana use by youth , and then, designed and developed discussion tools to encourage parent conversations about unhealthy eating and marijuana use with their child . This study contributes new data, in a sample of American parents with children between the ages of 10 to 17 years old, on the moderating effects of the discussion tools about unhealthy eating and marijuana use in parent-child discussions about these behaviors. The partial support of the moderating effects of parenting styles validates the need for further exploration of how these qualities could impact discussion outcomes of health risk behaviors.

Subsequent research should be directed at a longitudinal, nationwide study on whether parental motivations to discuss unhealthy eating and marijuana with their children could extend to random samples of parents in the United States and elsewhere. Additional studies could also include other risky behaviors in order to test whether authoritatively-framed discussion tools extend to other behaviors as well.Marijuana is the most widely used illicit substance worldwide . In 2010, more US high school students used marijuana in the prior 30 days than tobacco . Co-use with tobacco is of increasing interest . Smoking marijuana with tobacco, either in a tobacco leaf or mixed with tobacco, is an increasingly common practice among adolescents thought by some users to prolong the effects and/or increase the high from marijuana . A recent national online, anonymous survey of young smokers reported that roughly half also smoked marijuana in the past 30 days . Co-use of marijuana and tobacco may contribute to the development of nicotine dependence and thus, is an important area of research for the investigation. Adult co-users of tobacco and marijuana have an increased risk of developing nicotine dependence and have worse tobacco cessation outcomes . While overall rates of tobacco use and co-use with marijuana are lower in adolescents compared with adults , most addicted adults develop nicotine dependence during adolescence. Therefore, vertical weed grow adolescence is a critical period to study the effects of marijuana on tobacco.Although the transition from experimentation with tobacco to addiction is likely multifactorial, marijuana use may play a role for some adolescents and has been identified as a risk for nicotine addiction in a study of young adults . Possible mechanisms of action include common routes of administration ; hence, one behavior may reinforce the other. Furthermore, both nicotine and cannabis affect similar pathways within the mesolimbic addiction pathways, suggesting similar and overlapping mechanisms for addiction . Finally, smoking cues are also similar between the two substances, which may contribute to the poorer tobacco cessation outcomes observed in adult co-users of marijuana . Despite the increasing prevalence of marijuana use in adolescents, particularly among smokers, and evidence of harm from marijuana-tobacco co-use in adults, little is known about the interaction between marijuana and tobacco in adolescents. The goal of this study was to examine the severity of nicotine addiction among teen smokers as a function of co-occurring marijuana use. Given the literature on adult smokers, we hypothesized marijuana would contribute to symptoms of nicotine dependence among adolescents.Adolescents between the ages of 13-17 from the San Francisco Bay Area who smoked at least 1 cigarette in the past 30 days were recruited as part of an ongoing smoking trajectory study detailed elsewhere . Adolescents responding to online, school and clinic based advertising were invited to complete the study visit. Females with positive pregnancy tests were excluded from the study.Adolescent tobacco smokers completed in-person surveys of smoking behaviors and dependence scales. Tobacco use was measured by asking adolescents how many cigarettes they smoked on each day of the week. Participants who reported smoking on fewer than 30 of the previous 30 days were considered intermittent smokers .

Given the lack of consensus regarding optimal measurement of nicotine dependence in adolescents, the study administered the following four measures at study entry: the modified Fagerström Tolerance Questionnaire , the Hooked on Nicotine Checklist , the Nicotine Dependence Syndrome Scale , and the International statistical classification of diseases and related health problems, 10th revision criteria for nicotine dependence . All of the nicotinedependence measures were scored continuously with the total score on each measure used to quantify nicotine addiction.Frequency of marijuana use was categorized as: 1) never or no use in past 3 months, 2) Once a month or less plus once a week or less, 3) one or more times a week, and 4) every day. Spearman’s rho correlations examined associations between frequency of our ordinal measure of marijuana use with demographic variables, cigarettes per day and alcohol use. To examine the association between marijuana and measures of nicotine addiction , we ran general linear models with key variables that in the literature have been associated with nicotine addiction and marijuana use .Two hundred adolescents were consented into the study and completed the baseline visit. Of those, 28 denied smoking cigarettes in the past 30 days and 7 declined to answer the question about marijuana use and were thus excluded from the analysis. The resulting sample had a mean age of 16.1 years and was racially diverse, with 28% participants identifying as White, 19% African American, 19% Hispanic and 34% other. Participants averaged 3.01 CPD for a duration of 1.98 years . Fifty-one participants reported daily cigarette smoking and 111 reported non-daily smoking . Mean scores were 2.56 on the mFTQ , 4.52 on the HONC , -1.75 on the NDSS , and 10.13 on the ICD-10 . Most participants reported marijuana use in the past 30 days with 43 using weekly, and 62 reporting daily use. Frequency of marijuana use was correlated with CPD , but not with the frequency of alcohol use . Participant CESD scores were not associated with frequency of marijuana use or cigarette use . In general linear models controlling for age, years of smoking, and daily versus non-daily smoking, frequency of marijuana use was significantly and positively associated with nicotine addiction . The findings were consistent across all four measures of dependence and remained significant for the mFTQ after removing the question on CPD. When examining the NDSS subscales, only the drive and priority subscales were significantly associated with marijuana frequency. Older age, more years smoking, and daily smoking were associated with greater nicotine dependence in all models. The total percent of variance predicted ranged from 25% for the HONC to 44% for the mFTQ and NDSS. Illicit drug use may co-occur across substances, and follow-up analyses sought to examine whether the finding of an association with nicotine dependence was specific to marijuana. Therefore, we also assessed co-use with other illicit substances. In the past 3 months, 40 participants reported ecstasy use. A small number of participants reported use of cocaine/crack , methamphetamine , mushrooms/ mescaline , heroin , Percocet/Vicodin , or LSD , preventing inclusion in analyses. Ecstasy, included as a covariate in the fully adjusted general linear models, was not a significant contributor with p-values ranging from .24-.99 and the effects for marijuana remained largely unchanged.Marijuana smoking was prevalent in this adolescent sample of tobacco smokers: 80% reported past month marijuana use and more than a third smoked marijuana daily. Notably, among adolescent tobacco smokers who also smoked marijuana, the frequency of marijuana use was associated with greater levels of nicotine addiction on all three major scales used in studies with adolescents plus the ICD-10.

A significant association for only unhealthy eating was for lower authoritarian parenting style and higher self-efficacy of unhealthy eating, which is consistent with previous literature testing these relationships in similar contexts . Greater perceived risks of harms of unhealthy eating and marijuana use were associated with higher coherence and higher worry of unhealthy eating and marijuana use. These findings are consistent with, and extend, prior research on the influence of higher perceived risks of the harms of marijuana use in predicting higher worry of marijuana use , and now can extend to unhealthy eating. For unhealthy eating, another significant association included more negative prototypes of unhealthy eating and higher worry of unhealthy eating. Relatedly, negative prototypes have been shown to predict higher worry about one’s child using marijuana . Interestingly, there was not an association between negative prototypes of marijuana users and worry of marijuana use in this study, however, there was a positive association with higher coherence of marijuana use. Parental worry of unhealthy eating and marijuana use were positively associated with stronger intention motivations to discuss these behaviors with their child. This adds to prior research of worry in motivating a protective response , e.g., discouraging marijuana use . For unhealthy eating, there was also an unpredicted association between authoritative parenting style with intentions to discuss unhealthy eating with child. While for marijuana use, vertical growing weed higher coherence was associated with discussion intentions of marijuana use, as well as an unpredicted association with more parent-child communication, and greater levels of perceived risks and coherence of marijuana use.

These findings provide further support for the positive relationship of intention motivations in predicting discussions of unhealthy eating and marijuana use. There was also a significant association between higher worry of unhealthy eating with higher willingness to discuss unhealthy eating with one’s child. Additionally, unpredicted associations of higher levels of parent-child communication and perceived risks of harms of unhealthy eating, and more negative prototypes of unhealthy eating were positively associated with discussion willingness of unhealthy eating. For marijuana use, there was also an unpredicted association for higher self efficacy of marijuana use with higher willingness to discuss marijuana use with child. For intentions of unhealthy eating and marijuana use, there was a positive association with past discussion of unhealthy eating and marijuana use. These findings are in line with the substantial body of evidence that intentions are associated with health related behaviors . The predicted path of willingness did not associate with past discussion of unhealthy eating or marijuana use. Previously, willingness has been found to predict risky health behaviors , however, this might not extend to the behavior of discussing unhealthy eating and marijuana use with one’s child. Other studies have also found this to be true for willingness and discussion behavior path for marijuana use . One possibility is that parents may be more likely to participate in premeditated discussions with their child about health-related behaviors as compared with impulsive discussions . There were also unpredicted associations of higher levels of authoritative and authoritarian parenting styles, and more negative prototypes of unhealthy eating with past discussion of unhealthy eating with child. While, greater perceived risks of harms and coherence of marijuana use were associated with past discussion of marijuana use with child.

These present study findings can possibly serve as useful standards for developing discussion tools that include measures of parenting styles and PWM framework factors, in an effort to assist discussions of unhealthy eating and marijuana use with one’s child. Since, attachment styles did not predict any of the behaviors, it will not be included in the parenting-framed messages developed in Study 2 or the tools developed in Study 3. Although, they did have associations with parenting styles , and this association will be tested with correlational analyses in Study 2. These results support the potential utility of framing discussion tools with authoritative parenting style, but given that authoritarian style was also associated with motivations for discussion behaviors, it could be that an authoritarian-framed message might be helpful as well. Therefore, all three of the parenting styles will be further tested in Study 2 with youth. Lastly, this study evaluates child-age group differences in discussions of unhealthy eating and marijuana use . Discussion levels varied by child’s age, with parents of younger children discussing unhealthy eating, and parents of older children discussing marijuana use. With support of our hypothesis, it could be that parents may not discuss unhealthy eating with older kids, as they may feel that they are independent and can make their own decisions . However, adolescents across all age groups are likely to eat unhealthy , and respond well to recommendations on diet . In contrast, parents may be less likely to think that their children use marijuana at younger ages. In recent years, marijuana initiation is more likely to begin at younger ages with a decrease in perceived likelihood of harm of marijuana use . Given the changing landscape of marijuana legalization, it is imperative to continue to consider all age groups. Therefore, implementing a discussion tool that could provide parents with the necessary guidance to engage in communication about risky behaviors, regardless of their child’s age group, is an important first step.

Strengths of the present study include its focus on parent motivations to discuss unhealthy eating and marijuana use and its contributions to further inclusion of the parenting styles and revised PWM factors in motivating discussions about these behaviors, in a sample of parents in the United States. The association of parenting styles in motivating protective responses is essential to consider for development of discussion tools, and will be further tested in Study 2 and 3. Another strength is the use of MTurk, which has become a popular method used for recruiting large heterogeneous samples such as parents of adolescents from across the nation as has been demonstrated in several published psychological studies . Limitations of this study require consideration when interpreting the results and point to directions for future research. First, the results may not be representative of all parents across the nation or in other countries, as it consisted predominantly of NonHispanic White and well-educated participants. Second, the findings may not be generalizable to all parents, particularly as we focused primarily on parents of children ages 10 to 17 years old. Further research utilizing random samples of parents in the United States is needed especially with the changing landscape of marijuana legalization laws. A last limitation is that discussion behavior is measured as a past behavior rather than future behavior. However, the observed relationships of predictor variables with past behavior are likely to hold for future behavior as an individual’s behavior is fairly consistent, and typical behaviors, are more predictive than uncommon behaviors . Nevertheless, additional research is needed to test the predictive associations of the PWM factors on discussion behavior in the future.This chapter begins with a description of Study 2 including aims and hypotheses; methods ; discussion of manipulations ; detailed list of measures; overview of statistical analyses; results, discussion, and conclusion of study. Results from Study 1 suggested that parent motivations to discuss unhealthy eating and marijuana use with their child may be influenced by their parenting dynamics , and other cognitive factors . There is a need to develop a discussion tool that could be used by parents to engage in discussions with their children centered on these behaviors. One of the unique aspects of this tool is the inclusion of parenting-framed messages that was developed using characteristics of the parenting styles of authoritative, authoritarian, and permissive . These messages were assessed in order to figure out which parenting framed message was rated most effective to be used in the discussion tool for Study 3 with parents. The parenting-framed messages were developed by an attribute list of the three parenting styles so that each characteristic was addressed with each respective message . Prior to testing these parenting-framed messages with parents, commercial cannabis growers it is important to test the acceptability of these messages with youth. The focus is on youth ages 18 to 20 years old, as this age group is close to minors. More so, they will better articulate responses to parenting-framed messages with a more enhanced perspective as compared to a younger age group.

Importantly, Study 2 tests the receptivity by a child to the parenting-framed message based on the perceived parenting styles of one’s parent, whereas Study 3 tests the receptivity of the parent to use the discussion tools of unhealthy eating and marijuana use based on the parent’s perceived parenting style. This study also tests the associations of the attachment styles and parenting styles as perceived about one’s parent. Therefore, in Study 2 we assessed the parenting styles of one’s parent, while in Study 1 and Study 3 we assessed parenting styles with one’s child. Since, there may be variation across parent and child populations with regards to reports on parents’ parenting styles, it was important to test them both. The study aims were to: test the associations of the perceived attachment styles with a parent and the perceived parenting styles of the parent; test the associations of attachment styles and parenting styles on perceived effectiveness, perceived interpretability, motivations to discuss behavior, and discussion similarity; and test the relationship of parenting-framed messages of unhealthy eating and marijuana use on perceived effectiveness, perceived interpretability, motivations to discuss behavior, and discussion similarity. For Aim 1, we tested hypotheses that: lower attachment anxiety and lower attachment avoidance will be associated with higher authoritative parenting style; and higher attachment anxiety and higher attachment avoidance will be associated with higher authoritarian parenting style and permissive parenting style. For Aim 2, we tested hypotheses that: lower attachment anxiety, lower attachment avoidance, and higher authoritative parenting style will be associated with higher perceived effectiveness, higher perceived interpretability, higher motivations to discuss behavior, and higher discussion similarity for authoritative messages of unhealthy eating and marijuana use compared to lower authoritarian parenting style and lower permissive parenting style; and higher attachment anxiety, higher attachment avoidance, higher authoritarian parenting style, and higher permissive parenting style will be associated with higher perceived effectiveness, higher perceived interpretability, higher motivations to discuss behavior, and higher discussion similarity for authoritarian and permissive messages of unhealthy eating and marijuana compared to lower authoritative parenting style. For Aim 3, we tested hypotheses that: higher perceived effectiveness, higher perceived interpretability, higher motivations to discuss behavior, and higher discussion similarity will be associated with higher authoritative parenting-framed messages for unhealthy eating and marijuana use compared to lower authoritarian parenting-framed messages and lower permissive parenting-framed messages; and these message differences will be stronger for authoritative parenting style than for authoritarian parenting style or permissive parenting style.2.1. Participants The university’s institutional review board approved the study protocol. Participants were recruited through the university online research participation site to undergraduate students who are between the ages of 18 to 20 years old at the University of California, Merced. In total, 393 participants provided informed consent and were able to complete the study. Overall, participants were approximately 19 years of age on average and predominantly Hispanic with over 72% identifying as women and lower classmen . 2.2. Design The study utilized a 3 X 2 within-subjects design, with parenting-framed messages and the conditions of unhealthy eating and marijuana use. After completing measures of demographic and personal characteristics, and unhealthy eating and marijuana use, participants viewed a series of parenting-framed messages through counterbalancing. 2.3. Procedure Participants responded to questions about measures of demographic and personal characteristics, unhealthy eating and marijuana use, attachment and parenting styles, and parenting-framed messages. Participants viewed a total of six messages, and then rated the messages on perceived effectiveness, perceived interpretability, and motivations to discuss the behavior, and discussion similarity. The six messages were counterbalanced, with every participant viewing all three parenting-style message within in each of the two behavior conditions. Participants were randomly assigned to one of two behavior conditions , which were presented in random order to each group. For instance, one group was tested with unhealthy eating followed by marijuana use, and the second group was tested with marijuana use followed by unhealthy eating, and vice versa. Following the survey completion, participants read a brief explanation of the study and received links to websites of national health organizations with information about unhealthy eating and marijuana use. They then received SONA credit for their participation in the survey.

As part of the broader study, at baseline and annual follow-up visits, participants completed a comprehensive battery including neuropsychological assessment , self-reports of behavior, psychiatric symptoms and substance use, and a multimodal neuroimaging session . Exclusionary criteria for study entry included current use of psychoactive medication, current or persistent major Axis I psychiatric disorders, significant learning or developmental disorders and serious major medical conditions . While a majority of participants had limited drug and alcohol exposure at enrollment, a small proportion were recruited who exceeded age-specific alcohol and marijuana low-use thresholds . Additional recruitment, demographic and procedural details have been published previous . The NCANDA project employs an accelerated longitudinal design, and the current study used all available data across the first seven waves of data collection, from November 2012 to December 2020.To measure the Big Five personality dimensions, participants were administered the TenItem Personality Inventory , a brief measure shown to have convergence with longer Big Five measures as well as good test-retest reliability . The TIPI consists of 10 questions, with two questions for each subscale: extraversion, agreeableness, conscientiousness, emotional stability, and openness. Each question asked participants to rate on a scale of 1 to 7 how much a pair of words applied to them. The responses on the two questions for each subscale were averaged and served as the primary outcome measure for all analyses. Due to protocol changes during the fifth wave of data collection, pipp racks the study moved from administering the TIPI during all annual visits, to only administering it if participants were completing their age 24 or 27 visit .

Alcohol and marijuana use were measured using the Customary Drinking and Drug Use Record . At all visits, participants self-reported the number of days they drank and used marijuana during the past year. That is, participants were asked: “During the past year, , how many days did you drink alcohol?”, with an identical question asked regarding marijuana use. Due to non-normal distributions, past-year alcohol and marijuana use variables were log-transformed prior to all analyses.Previous studies investigating the development of personality across adolescence often used linear growth models with polynomial effects . However, when examining development across a broad age range, it is possible that data do not always conform to this restricted parametric growth model, and when examining group-level effects , different groups may not necessarily demonstrate similar developmental trajectories. Generalized Additive Mixed Models , an extension of generalized linear mixed models, do not assume the shape of developmental growth a priori, but instead allow for age-related non-linear smooth functions that best represent the relationship between predictor variables and outcomes . Similar to traditional linear mixedeffects models , GAMMs allow for appropriate modeling of the within-subject correlation of longitudinal data, as well as other important random effects . Here, we modeled changes in personality development as a function of sex using both GAMMs and LMEs, and present findings side-by-side in order to assessthe impact of modeling choice. All tested models can be found in Table S1. Analyses were conducted using R 4.1.1 .Generalized Additive Mixed-effects Models —To assess the effects of age and sex on personality development, we fit GAMMs using the ‘mgcv’ package in R and carried out a series of model comparisons, similar to the approach taken in recent neurodevelopmental studies . For each of the 5 TIPI scales, we fit three successive models that included age-related development across the whole sample , a main effect of sex , and differences in the age-related personality development by sex . All models included a random intercept per participant, family, and data collection sites.

When interpreting sex effects on personality development, it is important to note when first fitting Model 3, sex was included as a ‘factor’, resulting in the estimation of a separate smoothed age trajectory in male and female participants. While this has the benefit of producing interpretable smoothed terms for each group, a traditional interaction term, such as that seen in linear modeling, is not produced. Therefore, to test the statistical significance of sex-specific developmental trajectories, standard hypothesis testing was used to compare the log-likelihood values from each model . Then, to provide additional statistical support, Model 3 was refit with sex coded as an ‘ordered factor.’ Here, a smoothed age trajectory is calculated for the ‘reference’ group only , and a smooth term representing the difference between the developmental trajectories of the reference group and the other group was estimated. While this method provides less information regarding the shape of the age-related trajectory for each group, it produces an estimate and significance-testing for the difference between groups, akin to traditional linear interaction terms, and has also been used previously in developmental studies . Finally, to assess the association between substance use and personality, we modeled time invariant , linear time-varying , and quadratic time-varying associations of past year alcohol and marijuana use. These three potential associations could occur for alcohol use, marijuana use, or both, resulting in a combination of nine different models . Additionally, to capture potential sex-specific associations of alcohol use, marijuana use, our both, a total 27 additional models were necessary to exhaustively explore these relationships . These predictors were added to the best fitting developmental model compared using standard hypothesis testing. Linear Mixed-effects Models—To compare developmental GAMM results to models with more traditional polynomial growth parameters, we fit a series of LME models. Unlike GAMMs, which allow for the assessment of sex differences in non-linear personality development with only 3 models, the LME framework requires the iterative addition of consecutive higher-order polynomial age predictors to statistically assess the benefit of added model complexity. Here, we chose to assess the effect of 3 orders of polynomial effects , along with their potential interaction with sex, using the ‘nlme’ package in R . Starting with a linear age effect, we compared three successive models to assess the pattern of age-related development across the whole sample , a main effect of sex , and differences in the age-related effects by sex . This process was then repeated for quadratic , cubic polynomial age effects. For each interaction model, the effect of sex was assumed to interact with all lower-order polynomial age effects. Finally, the best fitting model for each polynomial age effect was then compared, to determine the final model. Identical to GAMMs, all models included a random intercept per participant, family, and data collection sites. Briefly, female and male participants identified as either white non-Hispanic , African American/Black , Hispanic/ Latino , Asian , multi-racial , Pacific Islander , or Native American/ American Indian . At baseline, 20% reported parents with education below a college degree, 27% with at least one parent attaining a college degree, and 53% with at least one parent with education greater than a college degree; annual family income ranged from below $12,000 to greater than $200,000. The TIPI was completed during at least one visit for 829 of the 831 subjects, with a total of 3,402 case observations across the 7 waves. However, 24 cases included incomplete reporting of substance use measures, and 4 cases included inconsistencies in reported substance use . To provide direct statistical comparison of nested models, only subjects’ timepoints with complete data were included in the final analyses.

Notably, all developmental findings remain unchanged when those timepoints with missing substance use values were included. In total 3,374 case observations across 829 subjects were included in final analyses; the breakdown by wave follows: Baseline , Year 1 , Year 2 , Year 3 , Year 4 , Year 5 , Year 6 . As expected alcohol and marijuana use both increased with age . Overall, 68% of the sample reporting drinking, and 48% of the sample reported using marijuana during at least one wave of data collection. Of those reporting substance use, vertical growing racks over the course of the study to-date, past year alcohol use ranged from 1 to 365 days with an average of 28.5 days per year, and past year marijuana use ranged from 1 to 365 days with an average of 49.1 days per year. Fit statistics and model comparisons for GAMMs examining age- and sex-related effects on personality development, and the association between personality and past year substance use can be found in Table S2. Parameter estimates of the final best-fitting GAMMs can be found in Table 1. All significant findings reported herein are from the final best fitting models, including the effects of past year alcohol and marijuana use. For models with sex-by-age and/or substance use-by-age interactions, models were refit with their intercepts adjusted to ages 13, 16, 19, 22 and 25 in order to provide added interpretation to underlying main-effects of sex and substance use. In the absence of standard parametric age coefficients in GAMMs, we report the effective degrees of freedom , which sheds light on the degree of nonlinearity for a given developmental trajectory . Effect sizes for all parametric coefficients are reported as standardized regression coefficients for continuous predictors and Cohen’s d for categorical predictors .The current study sought to flexibly model developmental trajectories of personality in adolescence and young adulthood as a function of sex and explore the association between substance use and personality across age. We report three general conclusions: 1) there were linear increases in agreeableness and conscientious and decreases in openness, across this age range, the slope of which did not differ developmentally by sex, and significant sex-specific non-linear developmental differences in extraversion and emotional stability; 2) male participants reported lower agreeableness, conscientiousness,and openness across the entire age range, less extraversion at all ages except during midadolescence , and more emotional stability in all but early adolescence ; 3) alcohol use was associated with greater extraversion and openness across the entire age range, and less conscientiousness in adolescence , while marijuana use was associated with less agreeableness throughout the entire age range, less conscientiousness in early adolescence and young adulthood , less extraversion in young adulthood , and less emotional stability throughout the entire developmental age range in female youth, and in young adulthood in male youth. Developmentally, our findings provide partial support for the maturity principle , as we found both conscientiousness and agreeableness to increase linearly from ages 12 to 25. This is consistent with at least one report that found agreeableness and conscientiousness increased consistently across adolescence and young adulthood , with non-linear effects occurring primarily in other traits . Meanwhile, another study found the lowest levels of agreeableness and conscientiousness occurred around ages 12–13 . Our data provide strong replication of these results, in a large multi-site cohort, and suggest that any “disruptions” seen in agreeableness and conscientiousness may take place during childhood, prior to their continued maturation in adolescence and young adulthood. Contrary to this effect, we note decreases in openness across the entire age range. While openness has been shown to decline in late childhood and early adolescence , there is no evidence, to our knowledge, of self-reported decreases in openness in late adolescence and young adulthood, though parent-reported adolescent personality findings suggest decreases in openness in this age range . Interestingly, out of all five personality traits, when assessed in adolescence, openness has been shown to have the lowest internal consistency, and replicability across multiple samples and cultures . Thus, it’s possible that our 10-item question of personality could be less sensitive to true mean-level changes in openness in this population. Our findings also provide partial support for the disruption hypothesis , as we found extraversion in both male and female youth, and emotional stability in female youth, decreased in early adolescence . However, unlike previous reports , we found extraversion never increased during late adolescence and young adulthood. Instead, male participants continued to show linear declines in extraversion, while female participants showed a leveling off of extraversion. This is where we believe our flexible analytic strategy helps clarify past results. For example, Borghuis, Denissen et al. tested only linear and quadratic growth parameters, and found U-shaped trajectories for extraversion. Similarly, when quadratic growth parameters were fit to our data , we replicated this previously observed effect in female participants; however, more flexible modeling suggest, this quadratic growth does not best fit the data.

Cumulative marijuana use over the 8-year follow-up period significantly predicted attention performance above and beyond effects accounted for by baseline attention scores, age, and practice effects. Another longitudinal investigation that covaried for baseline functioning before marijuana initiation found that, among individuals with prenatal exposure to cannabis, heavy marijuana users demonstrated poorer overall IQ, processing speed, and immediate and delayed memory compared with controls. One critique of previous research is that the observed neuropsychological deficits may be due to polysubstance use , family history of substance use disorders , or comorbid psychiatric disorders . Furthermore, cognitive deficits among marijuana users may be attributable to acute or subacute cannabis withdrawal . Therefore, the goal of this study was to characterize the neuropsychological effects of adolescent marijuana users without comorbid psychiatric disorders after approximately 1 month of abstinence. It was hypothesized that adolescent marijuana users would demonstrate significantly poorer cognitive function in areas associated with frontal, cerebellar, and hippocampal functioning , including processing speed,complex attention, new learning, and executive function compared with demographically similar control adolescents following at least 23 days of monitored abstinence. Adolescents were primarily recruited from local high schools and universities via distribution of flyers and ads. To assess for study eligibility, comprehensive telephone screening measures were administered to both adolescents and parents0 guardians. Inclusion criteria required that youth were between 16 and 18 years of age, vertical farming equipment fluent in English, and had a parent or legal guardian available to consent and provide medical and psychiatric history.

Exclusionary criteria included history of Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition Axis I disorder or use of psychoactive medications; history of chronic medical illness, neurological condition , or head trauma with loss of consciousness . 2 min; significant prenatal alcohol or drug exposure; complicated delivery or premature birth ; learning disability or mental retardation; first-degree relative with history of bipolar I or psychotic disorders; left-handedness; and non-correctable vision, colorblindness, or hearing impairments. If at any time during the 28-day abstinence period a teen reported or tested positive for any substance use, he0she was excluded from study and not included in any data analyses . All participants and their parents0guardians underwent written informed consent in accordance with the University of California, San Diego Human Research Protections Program. Teens were classified into two groups: a marijuana using or a drug-free group. A priori classification criteria for the MJ-user group included .60 lifetime marijuana experiences; past month marijuana use; ,100 lifetime uses of drugs other than marijuana, alcohol, or nicotine; and not meeting Cahalan criteria for heavy drinking status . Control group classification criteria were ,5 lifetime experiences with marijuana , no previous use of any other drug except nicotine or alcohol, and not meeting criteria for heavy drinking status .All participants from the current study completed the larger ongoing study . Initial youth and parent0guardian screening interviews were administered separately by trained laboratory assistants to assess eligibility criteria. Participants were informed of the purpose of the study, procedures, potential risks and benefits, and confidentiality. Both parents and youth were informed that all study data are confidential . If eligible after the initial screens, teens and parents were administered detailed interviews assessing demographic and psychosocial functioning, Axis I psychiatric disorders, and substance use history.

To facilitate open disclosure, parents and youths were interviewed by different lab assistants, and confidentiality was guaranteed within ethical and legal limits. Youths were monitored with supervised urine and breath samples every 3– 4 days for 4 weeks. Youths with positive urine samples or breath alcohol concentrations or who appeared intoxicated were offered the option of restarting the toxicology screen procedure at a later time or to discontinue the study. If toxicology results indicated cessation and maintenance of abstinence, the adolescent received an evaluation between Day 23 and 27. Of MJ using youth who initiated monitored abstinence, 5 individuals had data suggesting substance use during the 4-week period, leaving 31 abstinent MJ users for this study. Youth who did not maintain abstinence were discontinued and compensated for their time. Upon completion of the study, youth and parents0guardians received financial compensation for participation.The detailed screening interview included the Structured Clinical Interview measuring psychosocial functioning, activities, estimated pubertal stage, last menstruation , health history, and handedness, and the computerized NIMH Diagnostic Interview Schedule for Children excluded participants with major psychiatric disorders, including DSM-IV Axis I mood, anxiety, attention deficit hyperactivity disorder, and conduct disorders. Parallel modules of the computerized Diagnostic Interview Schedule were used for 18-year-olds who lived independently. Family history of psychiatric and substance use disorders was also assessed . Youth were then administered the Customary Drinking and Drug Use Record to assess lifetime and past 3-month use, withdrawal symptoms, DSM-IV abuse and dependence criteria, and substance-related life problems .

Youth were administered the modified Time-Line Followback to obtain detailed information regarding type, quantity, and frequency of drug use during the past month. The TLFB provides a detailed substance use pattern using a calendar format with temporal cues to aid recall. Teens were asked how much they used each of the following drugs: marijuana, alcohol, nicotine, stimulants , opiates , dissociatives0hallucinogens , sedatives , and misuse of other prescription or over-the counter medications. If the youth continued to be eligible, a parent or guardian underwent a detailed screening interview using the parent version of the SCI, including information on prenatal0 infant development, childhood behavior, age of developmental milestones, parental socioeconomic status , family history of psychiatric and substance use disorders and youth and family medical and psychiatric history. Parents0guardians were also administered the parent version of the C-DISC-4.0 and the TLFB to improve the reliability of the youth diagnostic and substance use reports. At the neuropsychological session, youth were administered the Beck Depression Inventory and the Spielberger State–Trait Anxiety Inventory to assess mood .The intent of the current study was to examine whether group status or extent of marijuana use was associated with neuropsychological functioning in a sample of adolescents who demonstrated approximately 1 month of abstinence. The primary finding was that, after controlling for alcohol use and depressive symptoms, adolescent marijuana users demonstrated poorer Complex Attention, Sequencing Ability, and Verbal Story Memory, and slower Psychomotor Speed compared with non-drug using control adolescents. Furthermore, dose-dependent relationships were observed between lifetime marijuana use and poorer cognitive performance in these same cognitive domains, even after controlling for lifetime frequency of alcohol use. In general, post hoc analysis revealed that composite score differences were primarily driven by a pattern of slightly poorer performance among the MJ-users across several individual subtests within a cognitive domain. More specifically, after correcting for multiple comparisons, MJ-users significantly differed from controls on both sequencing and error subtest scores from the Sequencing Ability composite score . MJ-users performed marginally poorer than controls on several other subtests, including the TMT Number Sequencing ; CVLT-II trial 1 recall, Digit Symbol, Digit Span backwards, PASAT 2-second trial ; and WMS-III Logical Memory first recall, immediate recall, delayed recall, and recognition scores. This finding is consistent with longitudinal research following adolescents with substance use disorders over 8 years, also finding dose-dependent relationships between cumulative marijuana use and attentional and executive functioning . These findings lend further evidence to the literature that marijuana use during adolescence is associated with poorer attention, memory, and executive functioning . This neuropsychological profile is consistent with the hypothesis, based on adult studies, that marijuana is primarily associated with frontal, hippocampal, and cerebellar dysfunction . Additional structural and functional neuroimaging research focused on abstinent adolescent marijuana users is necessary to confirm this hypothesis. The current neuropsychological findings differ from those of Pope and colleagues , vertical grow who found that deficits in attention, short-term memory, and psychomotor speed were no longer measurable among adult marijuana users following 28 days of abstinence. One possible explanation for this discrepancy is that marijuana use during adolescence may negatively impact neuromaturation and cognitive development, resulting in more severe cognitive consequences compared with use during adulthood. For example, introduction of cannabis during adolescence may interrupt pruning of gray matter or disruption of white matter myelination, especially in the prefrontal cortex , which continues to develop into early adulthood . The current findings are consistent with animal studies that found more severe cannabis-induced learning impairments among adolescents compared with adults and findings that early onset use is associated with increased morphometric, electrophysiological, and cognitive abnormalities among adult marijuana users .

It is unknown whether continued abstinence from marijuana results in neurocognitive recovery or subsequent healthy neurodevelopment among adolescents. Therefore, longitudinal studies are necessary to investigate the long term trajectory of cognitive and brain functioning in adolescent marijuana users. Greater lifetime alcohol use was unexpectedly related to better performance on psychomotor speed and complex attention, primarily among the marijuana users. Of note, individuals who met Cahalan and colleagues’ criteria for Heavy Drinker were excluded, so adolescents with regular heavy binge drinking histories were not included in the current study. Still, this finding is in conflict with previous studies demonstrating dose-dependent relationship between increased alcohol use and poorer attention and sequencing ability . One possible explanation is that some other unknown moderating factors may explain the relationship between increased moderate alcohol use and improved cognitive function in this sample. Another possible explanation is that marijuana use could be somewhat neuroprotective in combination with moderate alcohol use during adolescence. For example, we have found that alcohol using adolescents demonstrated significantly smaller left hippocampal volumes, while combined marijuana and alcohol using adolescents had volumes similar to nonusers . However, the combined users had significantly weaker correlations between hippocampal morphometry and verbal learning compared with healthy control adolescents, suggesting abnormal memory system functioning. Among adults, simultaneous use of cannabidiol and alcohol actually reduced blood alcohol levels compared with an alcohol-only condition , and combined marijuana and alcohol dependent adults have performed better than alcohol-only dependent adults on an overall mean efficiency score derived from a computerized battery of cognitive tasks . Thus, there is some evidence in the adult literature that the combined effects of marijuana and alcohol may not be as damaging as alcohol alone. Due to high rates of concurrent alcohol and marijuana use , we were unable to recruit a sizable sample of heavy marijuana users with no history of drinking for the current study, hindering our ability to tease apart the independent contributions of each substance. Additional animal and human research is necessary to further examine the independent and interactive effects of alcohol and marijuana use on neurocognitive function in adolescents. As with any neuropsychological study, it is important to consider the clinical implications of these findings. Marijuana users performed 0.62 standard deviations poorer than controls on the Sequencing Ability composite, but less than half a standard deviation worse on other composite scores. However, considering that almost half of high school seniors have tried marijuana and 5% use it daily , any observed differences in cognitive functioning is of concern. Notably, these group differences and dose dependent relationships were observed among adolescent marijuana users who may be considered high functioning, with high SES and parental income , good physical and neurologic health, above average intelligence and reading ability, and the ability to abstain from substances for at least 1 month. Furthermore, the marijuana users in this sample did not have comorbid conditions associated with neurocognitive impairments, such as conduct disorder or attention deficit hyperactivity disorder , groups were similar on family history of substance use disorders , and abnormalities were observed after nearly a month of monitored abstinence. Thus, the current results may underestimate cognitive difficulties among the general population of adolescent marijuana users, who are more likely to be current users with comorbid psychiatric conditions. Still, even subtle cognitive difficulty may result in negative consequences in school and work . Students may miss information presented in class due to poorer processing speed, initial learning, and complex attention and working memory. Indeed, although their verbal intelligence and reading ability were comparable, the marijuana users obtained significantly lower grade point averages and were more likely to demonstrate behavioral problems in school compared with controls. This finding may be a direct result of subtle cognitive difficulties, or due to effects of intoxication, sleep alterations, poor mood, withdrawal effects, and preexisting neurobehavioral problems for which the marijuana users are at increased risk.

Decreased yields or prices for transgenic rice, ceteris paribus, would reduce the gross rents from the technology. Furthermore, the seller of the transgenic seed is likely to charge a premium of up to 60 percent of total per-acre seed costs, depending on the pricing structure of the technology. Roundup Ready® and Bt seed for commercially produced transgenic crops has historically been priced from 30 to 60 percent higher than non-transgenic varieties, and price premia for LibertyLink® corn seed range from 0 to 30 percent, although average chemical costs per acre are typically greater . Furthermore, growers will likely pay at least part of the burden of the fees assessed by the CRCA. Assuming that these effects are constant per cwt of output, they can all be represented as a unit increase in costs in terms of net returns. Increased unit costs of this form, ceteris paribus, would alter the distribution of the rents between stakeholders but not dissipate gross rents. As points of reference, base assumptions on price and yields are $6.50 per cwt and 80 cwt per acre, so gross revenues from sales of rice output are assumed to be $520. A price premium of $0.25 per cwt for conventional rice as compared to transgenic rice with no associated change in yields would thus have the equivalent effect on net returns to the grower of a fee of about $20 per acre. Note that changing output prices does not affect the cost structure of the average farm operation and, thus, there is a direct, linear relationship between net returns and price. To calculate the impact of these effects, weed curing simple subtraction of the product of the price change and yield from the baseline scenario is appropriate. On the other hand, both a technology fee and the CRCA assessments directly enter the cost structure and, as such, affect interest costs as well.

Tables 4 and 5 lay out these effects. A 30 to 60 percent technology fee, assuming a seeding rate of 1.5 cwt per acre and price of conventional seed of $14 per cwt, is equivalent to $6.30 to $12.60 per acre. Total fees assessed as a result of the CRCA would currently be $8.50 per acre at identical seeding rates and yields of 80 cwt per acre, although it is unlikely that 100 percent of these assessments would be passed to the grower. Table 4 assumes no pass-through to growers of the legislated fees while Table 5 assumes the maximum pass-through, thus bounding the estimates. Both conservatively assume two applications of glufosinate per growing season. Without the CRCA legislation, adoption of LibertyLink® rice is profitable for a technology fee of $6.30 regardless of any realistic yield assumptions and profitable at a technology fee of $12.60 per acre so long as yield drag is no greater than 8.9 percent . With zero yield gains, net returns per acre in this range of seed price premium increase by between 21 and 25 percent over conventional rice returns with even greater benefits for those experiencing positive yield gains. If we assume a small price premium of, say, $0.25 per cwt, the technology is profitable for either yield losses of 7 percent with no technology fee or no yield change with an unrealistic $25.89 technology fee. This highlights the importance of yield and price assumptions on the calculation of net benefits. However, it is clear that, even with a small output price premium and a seed price premium at the upper end of the observed range, the most likely adopters will benefit from increased returns over costs. Allocation of maximum CRCA assessments to the grower slightly changes the per-acre benefits but does not affect the qualitative conclusions . Net returns over the baseline scenario with a $6.30 technology fee are no longer positive with an 8.6 percent yield drag nor for a $12.60 technology fee and a 6.7 percent yield drag. However, identical yields still result in net benefits of between $24.50 and $30.80 per acre, more than enough to cover a $0.25 price premium for conventional rice.

To bound the per-acre benefits, we assume a lower bound of $0.25 per cwt price premium and an upper bound of no price premium with no CRCA pass-through. Under these assumptions, we conclude that the per-acre benefits of the transgenic HT technology are between –$7.22 and $58.10 for any given California rice grower with a midpoint estimate of $21.90. However, if we restrict attention to those producers most likely to adopt, as defined by at least zero difference in net returns, yield drag at the lower end of the range can be as high as 1.2 percent and they will still adopt.The preceding deterministic sensitivity analysis accounts for heterogeneity in land, weed infestation, and management ability as well as for the distribution of the rents generated by the technology. However, the magnitude of these rents is determined primarily through assumptions regarding yield and the price of rice as well as base assumptions on the price of alternative herbicide systems. While these point estimates are based on the best information available, another approach is to parameterize the distributions of those variables, which can be perceived as stochastic, and use Monte Carlo simulations to estimate the distribution of the surplus benefits of the transgenic rice technology. We take the specification in the equation and estimate distributions for a transgenic yield premium, the transgenic-rice price, and a conventional-rice price premium. Yields for the HT cultivar are assumed to vary according to a symmetric triangular distribution centered around 80 cwt per acre with a minimum value of 72 cwt and a maximum value of 88 cwt . This distribution allows for the possibility of yield gains and losses and, with symmetry, tends to be very conservative given the state of weed infestation and resistance across the state. Prices for California rice are essentially determined on the world market and thus are not influenced by the individual producer.

Using historical data from USDA for 1986 through 2002, we assume a log normal distribution for output price with a mean of $6.50 per cwt and a standard deviation of 1.67. Finally, the price premium for conventional rice is assumed to be distributed as a skewed triangular with a most-likely value of $0.25 , a minimum value of zero, and a maximum value of $0.52 or about 8 percent. These values are consistent with experience with corn, soybeans, and canola cited previously . To run the simulations, the technology fee and all CRCA assessments are set equal to zero and 10,000 draws from the distributions are made for each of four scenarios, depending on which parameters are assumed random. This gives an estimate of the gross surplus generated by the technology before pricing and assessment policies determine the distribution of those benefits. The first and second simulations assume no price premium with yields only and with both yields and price random; the third assumes that yields and the price premium are stochastic with the output price fixed at $6.50 per cwt, and the fourth assumes that all three parameters are random. As peracre benefits do not vary with output price alone, this scenario is excluded. In addition, each simulation is run for two groups—one that exhibits yields across the entire range of the distribution, labeled “all producers,” and one in which attention is restricted to those growers who are expected to increase their yields with adoption of the transgenic crop. This group is labeled “yield gainers” and yields are distributed as a non-symmetric triangular distribution with a most-likely and minimum value of 80 cwt per acre and a maximum value of 88 cwt . The yield gainers are most likely to adopt the new technology, and results from these simulations may more accurately represent the distribution of benefits among those who actually grow transgenic rice. Results from the Monte Carlo analyses are reported in Table 6. Under these assumptions, gross benefits from the technology are generally positive except on the lower end of the distributions. Yield gainers, on average, see a return of between $9.84 and $11.60 per acre more than the overall average producer with a slightly smaller variance due to the smaller yield variance assumed for this group. For both groups, indoor cannabis grow system introduction of the price premium increases the variability of the benefits by more than the introduction of output price variability. The price premium also reduces the magnitude of the surplus gains by approximately $20 at the median. Table 6 does not account for CRCA assessments or technology fees, generally bounded between $6.30 per acre and $21.10 per acre . Although not exact, a “back of the envelope” calculation suggests that median farm-level benefits, after accounting for these fees, are expected to be positive; however, not all farmers will see increased returns. The same is true for yield gainers in that median benefits are greater than $21.10 for each scenario but the lower end of the distribution may experience negative returns from adoption. The majority in each group, however, will benefit. More specifically, the exact probabilities of net returns greater than zero can be calculated. Assuming all three parameters are stochastic and bounding the fees according to the preceding assumptions, the probability that net returns are greater than zero for all producers is between 60.14 and 85.8 percent. For yield gainers, this range increases to between 89.4 and 100 percent, once again highlighting the importance of yield assumptions on net returns and hence on adoption.To further test the potential adoption impacts of the LibertyLink® transgenic rice variety, we apply the preceding methodology to the results of a three-year field study conducted by Fischer . The study covered growing seasons between 1999 and 2001 and was funded by DPR. The exercise uses the weed-management regimes and corresponding yield measures of the Fischer study, together with the pricing assumptions previously maintained, to estimate net returns for a hypothetical farm using identical herbicide rotations. To elaborate, Table 7 describes the rice-variety and herbicide-treatment regime used in each year of the Fischer study. The project was implemented on a rice field in Glenn County, California, on which watergrass was found to be resistant to molinate, thiobencarb, and fenoxaprop—three of the four chemicals registered in the state to control grass weeds at the time of the study . Four treatment regimes were analyzed: continuous molinate each year, an intensive combination of several chemicals each year, a rotate-mode-of-action regime in which chemicals with differing properties were rotated from year to year, and a continuous transgenic regime resistant to glufosinate. Each regime was applied to four plots of 0.57 acres each, and indicator measures such as yields were averaged for each treatment group . It is important to note that the choice of treatment regime was not related to economic considerations but, rather, to evaluation of the effi- cacy of differing treatment regimes under resistance conditions .To estimate potential returns over operating costs, the yield and herbicide regime data are used in conjunction with the structure presented in Table 2 to estimate per-acre costs and revenues on a hypothetical farm unit. Herbicides, custom operations, contract operations, interest on operating capital, assessments, and yields vary according to the experimental data while the remainder of the cost components are held constant at the levels presented in the first table. Again, to provide a basis for comparison, we set output prices for the transgenic variety equal to the conventional product and the CRCA assessments and technology fee equal to zero. Table 8 reports the results of the exercise. The first year of the trial included eight plots planted with LibertyLink® M-202 seed treated once with varying levels of glufosinate mixed with ammonium sulfate and eight plots planted with conventional M-202 seed, four of which were treated once with molinate and the remainder of which were treated once with propanil. The continuous-molinate treatment served as a baseline for the entire experiment as the field had demonstrated watergrass resistance to this particular chemical . From an economic standpoint, the intensive-combination regime was slightly superior to the two transgenic regimes with net returns per acre approximately 4 to 10 percent greater but less than the yield advantages of 8 to 13 percent. As operating costs for this treatment were higher than those for the transgenic rice, the difference in returns is explained primarily through yield advantages.