While many of the existing studies report deficits across several neurocognitive domains, no study had investigated the rate and pattern of neuropsychological recovery in heavy episodic drinking teens throughout the initial days to weeks of abstinence from alcohol . Further, to the best of our knowledge, no existing study had ensured groups’ comparable academic functioning that predates initiation of substance use , which limits the ability to make generalizations about the impact of alcohol as compared to preexisting differences. By ensuring comparable, premorbid academic functioning and by following adolescents over several weeks of abstinence, this study aimed to elucidate the pattern of neurocognitive recovery during early abstinence from heavy alcohol use. The final study built on the existing literature in two ways: addressing the limitation of the high rates of comorbid substance use among adolescent samples and comparing directly substance using groups to each other instead of just to non-using youth. Given that many alcohol-using populations have moderate to high levels of marijuana use, and similarly, many marijuana-using teens have significant exposure to heavy drinking, it was important to design a study that strictly defined the criteria of the groups to minimize substance use other than the one of interest, and directly compared alcohol-using youth to marijuana-using youth to those who use both substances. The study examined the effects of alcohol and marijuana use during adolescence in a sample of substance using teens and demographically-similar non-using teens using a neuropsychological battery after four weeks of monitored abstinence. Using strict criteria to differentiate groups, the study compared neuropsychological performance among alcohol users, marijuana users, those who use both marijuana and alcohol, cannabis trimming trays and non-using controls. To the best of our knowledge, direct comparisons among these groups following four weeks of monitored abstinence have not been previously reported. Overall, this body of literature aims to elucidate the pattern of recovery of emotional reactivity and neurocognitive functioning during early abstinence from alcohol among heavy adolescent drinkers.

Such knowledge may have important implications for improving academic and social functioning and reducing relapse risk among users. Additionally, the body of work aimed to identify the unique contribution of alcohol and marijuana or concomitant use to neuropsychological outcomes following one month of abstinence. Possible decrements in functioning among adolescent substance users may have a significant impact on adolescents’ daily experiences in academic, occupational, or personal settings. With knowledge of deficits, educators and parents may be able to improve outcomes for these teens by considering their cognitive abilities during instruction and employing strategies of repetition and active learning to more effectively engage and instruct a population of substance using youth.Current theoretical models of abuse and dependence posit that a propensity for stronger negative affect magnifies risk for progression to alcohol dependence and that a stressor provokes additive risk for return to use among adults who recently completed treatment . In adults with substance use disorders, low tolerance for distress is predictive of treatment dropout and shorter abstinence attempts . This progression from heightened negative affect and low distress tolerance to relapse may be due to expectations of both negative and positive reinforcement from substance intake . Such decisions to return to use or to continue to use are influenced by rational cognitive processes as well as by negative emotions that further direct behavior . Furthermore, individuals with low distress tolerance may have difficulty persisting in a task when experiencing negative emotions and rely on disengaging from the stressful activity to provide relief . The prefrontal cortex, which is involved in decision-making and impulse control, undergoes continued development during adolescence and young adulthood . Therefore, the risk for impulsive decision-making associated with negative affective states and low distress tolerance is elevated in youth , especially among teens who misuse alcohol or drugs . Among adolescents with histories of alcohol problems, negative affect and low distress tolerance are associated with increased probability of alcohol use . These factors are also considered risk factors for relapse among youth with alcohol use disorders , especially during early abstinence when affective disruption is most pronounced .

Furthermore, protracted heavy drinking may provoke negative affect and diminish problem-solving abilities , thereby compromising distress tolerance and decision-making skills during this critical time. In the context of ongoing neurodevelopment, the combination of low distress tolerance, elevated negative affect, and a tendency towards negative reinforcement or reward-dependence may place abstaining adolescents at particularly heightened risk for return to problematic drinking. Adult research has demonstrated that improvements in mood after sustained abstinence may contribute to decreased emotional reactivity and improved distress tolerance, but this possibility has not yet been explored in adolescent populations. To date, no study has investigated the rate and pattern of changes in emotional reactivity and distress tolerance during the initial days to weeks of abstinence from alcohol in heavy drinking youth . Elucidating the features of emotional improvements during early abstinence may have important implications for improvements in academic and social functioning among nonclinical heavy drinking youth, prevention, early intervention tailored to different stages of use and recovery, and reduction of problematic use among youth with alcohol use disorders.Many researchers have examined relapse phenomena via self-report outside of a relapse risk context, either using retrospective report of previous relapse events or in the context of longitudinal studies that utilize prospective reports , yet without proximity to the additive impact of stress. This study introduced an objective stressor to examine affective response, cognitive performance, and distress tolerance in heavy episodic drinking and non-drinking adolescents and to assess potential group differences and determine whether affective reactivity, performance, and distress tolerance improve over a four-week period following cessation of substance use in the heavy drinking youth. This study utilized a modified version of the Paced Auditory Serial Addition Test to provide a challenging cognitive task that assessed cognition and generated negative affect in the context of an objective stressor to measure emotional reactivity . During the final stage of the PASAT-C, participants were provided the opportunity to persist in the task in the presence of negative affect or terminate the source of negative affect by quitting the task .

The PASAT-C created an opportunity to test a negative reinforcement model by employing a behavioral measure that provides measurable responses in close proximity to a stressor. We expected that both heavy episodic drinkers and nondrinkers would evidence negative affect in response to the task; however, we hypothesized that heavy episodic drinkers with limited abstinence would show more pronounced affective responses that would improve as length of abstinence increased. We also predicted that heavy episodic drinking youth would show impacted cognition and impulsive decision-making , and that task performance as well as behavioral persistence would improve with extended periods of abstinence.Relations between emotional reactivity, task performance, distress tolerance, and alcohol use history were also explored. Participants were recruited from local high schools, colleges, and community settings via mailings and fliers .Interested students responding by phone were independently screened to determine eligibility. All interested teens and their parents underwent a subsequent, detailed phone interview to confirm eligibility. To ensure findings were due to heavy drinking and not impacted by other factors shown to influence cognitive performance, emotional reactivity, or distress tolerance among youth, exclusionary criteria included history of alcohol dependence, non-alcohol related DSM-IV Axis I or II psychiatric disorder; extensive or recent drug use other than alcohol ; neurological dysfunction/trauma; serious medical illness; prenatal alcohol/drug exposure; sensory problems; and use of psychoactive medications.Participants completed the PASAT-C task on three occasions at two 2-week intervals following cessation of alcohol use. During PASAT-C administration, numbers were presented on a computer screen, weed trimming trays and participants were asked to add the number that was most recently presented with the number that appeared prior to it. The PASAT-C task presented three stages with varying latency between number presentation to measure performance on a challenging neuropsychological test that involves working memory, attention, and arithmetic capabilities, and introduce a cognitive stressor to assess negative emotional reactivity and distress tolerance. Prior to initiating the task and at the completion of the second stage, subjects were asked to rate their negative and positive emotional states on a visual analog scale ranging from 0 to 100 . Differences in those ratings were used to assess emotional reactivity. During the initial ‘performance’ stage, numbers were presented in 3-second intervals to assess a participant’s ability to complete the task. During the second ‘negative affect induction’ stage, the latency period was decreased to 2 seconds to decrease participants’ success rates and provoke negative affect. Finally, during the third ‘distress tolerance’ stage, the latency period was further decreased to a 1-second interval and participants were offered the opportunity to persist with the task in the presence of negative affect or terminate the source of negative affect by discontinuing the task.

In line with published work , performance was measured by the number of correct responses on the first stage, emotional reactivity was measured as the difference between pre-test affect and affect following the second stage, and distress tolerance was measured as time to discontinue the third stage as it indicated how long they were willing to persist in the presence of a cognitive stressor.Participants were compensated for their time and abstention throughout the four weeks to maintain commitment and reward sustained abstinence, with a bonus for study completion to encourage continuation. Four HED drank alcohol between sessions 1 and 2 and data collected after their alcohol use were excluded from the present analyses. To minimize the impact of study participation on subjects’ daily lives, research staff worked closely with enrolled youth to select a one month period that did not conflict with birthdays, school events, or breaks. As this was not a treatment seeking sample, eligibility was not contingent upon a teen’s expressed desire to quit drinking. Instead, participants were motivated by financial compensation and the opportunity to contribute to research.Comparison of socio-demographic characteristics between groups was conducted on distributions, means, and standard deviations using chi-square tests for categorical variables and t-tests for continuous variables. Primary analyses were carried out with linear mixed model analyses of repeated measures, with participants entered as a random term, time point , and an interaction between time point and group. This approach is used in similar situations as a repeated measures ANCOVA, except that the linear mixed model allows us to retain data for the four participants who dropped the study and had only one valid data point. The mixed model analysis provided a convenient way to model error structures among repeated dependent variables; we modeled the structure of the means using fixed effects, specified a covariance structure for both between and within subjects, and fit the means model accounting for specified covariates . Interactions were evaluated with likelihood ratio tests for the comparison of nested models. In this study, models with and without the interaction terms were evaluated with the LR tests whose sampling distribution approximates a chi-square distribution with degrees of freedom equal to the difference in degrees of freedom between the two models . To be consistent with prior research and to limit the impact of skill or affective responding in the analyses, we took a conservative approach and covaried for baseline mood state and task performance in the linear mixed models examining affective reactivity and distress tolerance. Because performance may be influenced by pre-task mood states, we included pre-task mood in analysis of the performance stage. Secondary analyses examined the associations between alcohol use characteristics and affective reactivity, task performance, and time to discontinue the task in the distress tolerance stage. Due to non-normal distribution of alcohol use characteristics and task discontinuation times, Spearman’s correlations were calculated to describe these relationships.Initial analyses examined baseline mood states of HED and CON and although positive and negative mood varied across individuals , groups did not differ in pre-test mood states at any of the three testing time points . As designed, the negative affect induction stage of the PASAT-C task provoked negative affect beyond baseline mood in both CON and HED with feelings of frustration, irritability, and anxiety increasing and the positive feeling of happiness decreasing from the onset of the performance stage to our assessment time point following the negative affect induction stage .

Future research should thus work on validating a vicarious racism questionnaire in order to allow researchers to properly collect much-needed data on different aspects of this construct, especially as vicarious racism becomes more pervasive in the modern era. Another limitation regards some of the study results. Although we found that the link between frequency of vicarious racism and substance use depends on ethnic identity, it is important to note that the simple effects at high and low levels of ethnic identity were not significant. Future research should examine this interaction with larger sample sizes, include a more precise measure of alcohol and marijuana use , and/or consider a manipulation of ethnic identity rather than a self-report measure.In the wake of increased legislation sanctioning the recreational and medicinal use of cannabis in the United States, there is growing interest on the impact of cannabis on other substance use, including alcohol . Alcohol consumption and related consequences are of significant public health concern, as alcohol is the 3rd leading cause of preventable death in the United States , 2013. Cannabis is frequently used with alcohol, and this co-use has been associated with increased alcohol consumption, consequences, and alcohol use disorder . Individuals with cannabis dependence have nearly double the long-term risk for experiencing alcohol related problems and are more likely to develop AUD compared to drinkers who do not use cannabis. Further, cannabis use during alcohol treatment is associated with negative alcohol-related treatment outcomes . Despite the clinical and public health risks associated with co-use, questions remain whether cannabis use acts as a substitute or complement for alcohol use , mobile shelving system and whether these patterns change over time. Regarding substitution, individuals abstinent from cannabis reported greater alcohol consumption and craving during an experimental abstinence period .

State-level policy studies also find that cannabis can function as a substitute for alcohol consumption . There is equally compelling evidence that cannabis acts as a complement to alcohol use: the majority of epidemiological studies, as well as studies examining individual-level outcomes, indicate cannabis use is related to increased consumption of alcohol . Thus, it is critical to use nuanced measurement of alcohol and cannabis use, including daily and event-level studies, in order to clarify these patterns. Rather than examine the effects of cannabis on alcohol consumption, to date most event level studies of co-use have examined outcomes and consequences related to simultaneous use of alcohol and cannabis among adolescents and college students or effects of co-use on cannabis intoxication or use . However, recent work found that daily cannabis use among veterans was associated with increased likelihood of same-day moderate drinking compared to no drinking, and same-day heavy drinking compared to moderate drinking . Similarly, the first longitudinal study examining the effect of cannabis use on alcohol use found that cannabis use days were associated with more drinks and higher estimated blood alcohol concentration compared to non-cannabis use days. This study also found that these associations strengthened over the course the study , suggesting the link between cannabis use at the daily level and more drinking increases over these formative years. Although compelling, data collection for this study included a sample of college students, limiting generalizability. In addition to person-level factors such as age , several moderators of the association between cannabis and alcohol use have been identified. Metrik et al. revealed that individuals with an AUD were significantly more likely to drink heavily on cannabis use days compared to drinkers without an AUD; however, individuals with cannabis use disorder were significantly less likely to drink heavily on cannabis use days. In Gunn et al , pre-college levels of alcohol use and problems predicted increased alcohol consumption on cannabis use days.

Together with clinical and epidemiological studies, this research suggests that those with problematic alcohol use or AUD are at increased risk for heavier consumption when also using cannabis. However, a potential substitution effect may be present for individuals who are using cannabis at heavy or dependent levels—specifically for those without any evidence of AUD—as their demand for alcohol may be diminished in the presence of cannabis . To further elucidate the nature of the cannabis-alcohol association, it would be informative to closely examine medicinal cannabis users, who report using cannabis at a daily or nearly daily level . Medicinal cannabis users have cited use of cannabis as a substitute for alcohol and as a way to better manage alcohol withdrawal symptoms . Among medicinal cannabis users, cannabis may be less strongly associated with increased alcohol consumption. For instance, national data suggest that medicinal users are less likely to have an AUD compared to recreational users . In a large study of veterans, those who reported cannabis use for medicinal purposes also reported using alcohol less frequently, compared to those who reported only recreational cannabis use . Finally, veterans who use cannabis recreationally report higher frequency of alcohol use and are more likely to report alcohol intoxication as a motive for cannabis use . Together, these studies suggest that medicinal users may use cannabis to reduce alcohol consumption . However, to date, there are no event or daily-level examinations of the association between cannabis and alcohol use among medicinal versus recreational cannabis users.Multilevel modeling was used to conduct all analyses as data are nested within individuals, using the lmer4 package within R . A series of linear mixed effects models tested the prediction of number of drinks by cannabis use across all days and moderation of these effects by subject-level variables .

Dependent variables in all three models were daily number of drinks as self-reported on the TLFB. All models included fixed effects of percent of cannabis use days , calculated from all TLFB days as a percentage of those days in which any cannabis was used . All models also included fixed effects of any daily cannabis use , time , baseline age, any daily cigarette use , any other daily drug use , day of the week , and random effects for individual. The initial model examining the longitudinal effect of daily cannabis use on alcohol consumption also included the interaction of time and daily cannabis use. For the model examining moderation by type of user , time and two and three-way interactions between time, type of user , and daily cannabis use were included. For the final exploratory analysis examining moderation by alcohol substitution reason among medicinal users only, time and two- and three-way interactions between time, substitution reason , and daily cannabis use were included. Due to the small number of females in the sample and the effect of sex being non-significant in all models, sex was removed from final analyses. Initial models also included marital status, race, and ethnicity, which were also non-significant and removed from final analyses.This is the first study to examine day-level associations between daily cannabis use and alcohol consumption among medicinal and recreational cannabis users. We examined: whether daily cannabis use predicted increased daily alcohol consumption across 18 months; whether recreational cannabis users would drink more on cannabis use days compared to medicinal users; and the role of cannabis as a self-reported substitution for alcohol among medicinal users. Results indicated that cannabis use was associated with higher levels of alcohol consumption at the daily level, and that this effect was consistent over time. There was also a significant moderation by type of user, in that recreational users drank more on cannabis use days compared to medicinal users. Follow-up analyses showed that among these medicinal users, those who reported more frequent use of cannabis to substitute alcohol were more likely to drink less on cannabis use days. Our findings are consistent with other studies suggesting complementary use of alcohol and cannabis among recreational users . Further, mobile racking significant negative effect of time and cannabis use on alcohol consumption was detected in our initial model, and in our second which considers type of user. However, in both models, these effects are of small magnitude, suggesting that the positive association between alcohol and cannabis use is relatively stable, but may reduce, over time. Although this is inconsistent with a recent study of college students in their first two years of school, which found a strong positive association between time and cannabis use on daily number of drinks , this discrepancy may be a function of the unique samples.

Compared to the present study sample of veterans, of which 45% and 35% had an AUD and CUD respectively at baseline, college students in their first two years of school in Gunn et al. were following a population-based trend of increased alcohol consumption during this developmental period . Our results supporting complementary use are also consistent with prospective studies that suggest cannabis use during treatment for alcohol use may result in poorer alcohol-related treatment outcomes . Taken together, although results were of relatively modest effect sizes, this daily-level study suggests that cannabis use consistently complements alcohol consumption over time among recreational users. Further, our finding that type of user moderated the effect of cannabis use on alcohol consumption helps to elucidate conflicting evidence in the field as to whether cannabis acts as a substitute or a complement to alcohol consumption . Results suggest that cannabis is more likely to act as a substitute among medicinal users, but not recreational users. These results are consistent with other survey studies suggesting that medicinal users report using cannabis as a substitute for alcohol . Overall, it may be that those who use cannabis for medicinal reasons may be less likely to experience the additional risks associated with co-use, compared to recreational users. Consistent with other studies , our sample of medicinal users were less likely to have an AUD and drank on fewer days compared to recreational users. However, our sample was also more likely to have a CUD and reported more frequent cannabis use days and couse days across the assessment period. Therefore, although medicinal users may be less likely to experience clinically significant symptoms related to alcohol use, they were more likely to meet criteria for a CUD. However, this finding should be tempered by an important consideration in the literature regarding whether assessment methods for DSM-5 CUD symptoms translate for medicinal users. For instance, Loflin et al. suggest that symptoms that assess frequency and density of cannabis use may not be as indicative of problems in medicinal users compared to recreational users. Our preliminary follow-up analyses examining the role substitution among medicinal users confirmed that those who reported using cannabis to substitute for alcohol’s effects more frequently were less likely to drink more on cannabis use days, compared to medicinal users who reported less frequent substitution. The present study has important implications for treatment and prevention. First, our results are consistent with several other recent studies of treatment samples suggesting that recreational use of cannabis is associated with increased alcohol consumption and should be avoided for those in treatment for AUD or alcohol related problems. These findings suggest caution should be taken in the wake of changes in recreational cannabis policy, as increased cannabis use could lead to increased problematic drinking among recreational users . In addition, there is a clear documented negative impact of cannabis use on AUD recovery for individuals with AUD in alcohol treatment . Medicinal cannabis users in our sample consumed alcohol less frequently than recreational cannabis users, which could be interpreted as an additional indication that medicinal cannabis may serve as a replacement for alcohol use. However, these data were drawn from an observational longitudinal study not limited to an alcohol treatment-seeking sample and should not be applied to those in treatment for alcohol misuse. Furthermore, veterans in this sample endorsed a number of conditions for medical cannabis use including anxiety, stress, PTSD, pain, depression, and insomnia . Therefore, besides using cannabis as a substitute for alcohol, there may be important additional moderators among reasons for medical cannabis use that could clarify the cannabis-alcohol co-use association.This study should be understood in the context of several limitations. First, although the TLFB has established reliability and validity, it does require retrospective recounting of substance use. As with all self-report measures, this may be subject to recall biases.