These latter studies lend initial support for a harm reduction model also in cocaine use disorder treatment. In unpublished neuroimaging studies of 20 PSU patients between 1 and 4 months of abstinence , we found evidence for widespread volumetric change also in individuals who co-abused alcohol and stimulants for more than 20 years: an increase in left caudate volume, a decrease in right superior temporal lobe volume, and trends to decreasing insula and entorhinal cortex volumes . These changes, however, were much less dramatic than observed in short-term abstinent AUD described above. Given that abnormalities in PSU involved both smaller and larger regional tissue volumes , observing both volume increases and decreases across different brain regions during sustained abstinence is not surprising and may relate to the competing morphometric processes and altered functional connectivity postulated among these brain regions. Longitudinal MRS studies have been used to try to further understand the tissue changes that underlie volume changes during recovery. We showed in a series of studies in recovering AUD that after correcting for parallel tissue volume changes, NAA and Cho concentrations throughout the brain recovered significantly, but variably over 5 weeks of abstinence, with some of the metabolite changes related to improvements in specific neurocognitive domains . The brain metabolite recovery was generally greater in nonsmoking than smoking AUD , with less frontal white matter NAA recovery related to longer smoking duration . In an MRS study of recently abstinent methamphetamine abusers, low Glu in ACC recovered over 5 months of abstinence, together with a reduction of craving . Over just 4 weeks of abstinence, however, prefrontal NAA and Cho in intravenous methamphetamine users did not change significantly , in contrast to observations in short-term abstinent AUD. In our small cohort of abstinent PSU, regional metabolite concentrations recovered between 1 and 3 months of abstinence to levels commensurate with controls . Specifically, NAA and Cho in the dorsolateral PFC and GABA and NAA in the ACC significantly increased, while Glu and mI in the ACC and mI in the parieto-occipital gray matter decreased; the NAA increases in ACC and dorsolateral PFC correlated with improvements in visuospatial learning and working memory, respectively. The observed brain tissue volume and metabolite level changes during abstinence from alcohol and/or substances may partially reflect the reversal of maladaptive neuroplastic processes associated with chronic long-term alcohol/substance abuse . While initial significant neurobiological changes have been observed within the first month of abstinence in AUD,cannabis grow setup fewer studies describe such early processes in illicit substance users, reminiscent of the dynamics of potentially related neurocognitive improvements.

Neurobiological improvements are observable over many months, even years after initiation of abstinence. They are likely not the result of a single neural process but of several different processes involving different cell types and populations to various degrees—sometimes potentially with opposing effects on regional MR-based outcome measures and with various temporal dynamics. Given the demonstrated associations between neurobiological and neurocognitive measures, this may give rise to the relatively large variability observed for neurocognitive recovery across different substance-using groups and among individuals in the same substance-using group during abstinence. Data from humans and animal models suggest the tissue volume recovery in AUD during early and extended abstinence is related to increases in neuronal dendritic arbor, soma/cell volume, synaptic density, nonreactive glial proliferation , and remyelination , which are all intrinsic neuroadaptations that are also instrumental in experience-based learning and memory . The metabolite concentration changes that often accompany morphometric changes during abstinence may also be related to these mechanisms. Clinically relevant modulators of the degree of regional volume reduction in adult AUD and of the extent of structural recovery during abstinence have been identified; they include age, gender, family history of problem drinking and genetic factors, degree of baseline atrophy, number of detoxifications, and comorbid medical , psychiatric , and SUDs including tobacco use disorder . The same factors as well as stress and stress response also modulate metabolic and functional brain injury and recovery in AUD. Finally, a critical determinant of brain injury is the age of onset of substance use, with substance-associated brain changes in adolescents being different both qualitatively and quantitatively from those in adults, as they likely interact with brain development. Studying the effects of substance use cessation in the developing brain is in its infancy, with the current Adolescent Brain Cognitive Development Study, a longitudinal, observational study of over 10,000 youth recruited throughout the United States, promising to address this issue. Given these many modulators of neurobiology in alcohol and SUDs, some of which are also risk factors for relapse , neurobiological and neurocognitive recovery with abstinence from alcohol and other substances is complex and not trivial to study and interpret in a meaningful way.One successful example of such development is the now much more widespread integration of smoking cessation into substance abuse treatment: tobacco use, a significant but modifiable health risk for both relapse and common psychiatric comorbidities in AUD, has a greater annual mortality than SUD and AUD combined, and we can ill afford to continue ignoring it in addiction treatment . It has been demonstrated that treating tobacco use effectively in those seeking treatment for their substance abuse may promote better long-term outcomes . But our efforts cannot end here, as newer forms of nicotine delivery also need to be considered carefully regarding their addictive and brain-altering potentials.

Despite the seemingly overwhelming complexities in studying brain function, morphometry, and recovery in human addiction, demonstrating specific neuroadaptations after detoxification, their time courses, and their dependence on critical modulators are important for several reasons: There might be an optimal window of opportunity for augmenting such intrinsic neurobiological repair processes via interventions such as plasticity-based cognitive remediation, magnetic/electrical stimulation, or pharmacotherapy; many neurocognitive deficits and/or their neurobiological correlates are not premorbid/risk factors of abuse, but rather consequences of abuse, and brain function and tissue integrity can improve with sustained abstinence; and relapse risk likely decreases over time with abstinence as brain neurobiology and functions recover from injury . Identifying the specific neurobiological mechanisms associated with such improvements, their mitigating factors, time courses, and trajectories can critically inform interventions aimed at facilitating brain repair and recovery processes, such as strengthening prefrontal neural connectivity or employing GABAergic therapy to improve inhibitory control. A recent opinion piece calls for “expanding and deepening the neuroscience of recovery from addiction” to improve addiction-focused clinical care and public policy. In that spirit, we hope that this chapter contributes to describing a critical part of the current state of addiction recovery research. Finally, it is noteworthy that all recovery research described in this chapter has been conducted in individuals having achieved complete abstinence from alcohol and other substances. Research has rarely examined psychological or physical functioning in moderation-focused treatment approaches . Given the increasing consideration of treatment outcome endpoints other than complete abstinence,outdoor cannabis grow future research will almost certainly be conducted to better understand the degree of neurobiological recovery associated with reduced substance use . Additional research might focus on recovery processes that go beyond the standard treatment durations of several months described here, to better understand neuropsychological and neurobiological factors associated with sustained recovery in later years when treated individuals remain at some degree of relapse risk. Electronic cigarette , or nicotine vape, use among youth and young adults has been increasing in the United States , a cause for concern due to potential nicotine addiction, increased risk for use of other tobacco products and drugs, and long-term health risks .

Evidence has also shown a wide array of short-term adverse experiences attributed to ecigarette use . E-cigarette, or Vaping, Product Use-Associated Lung Injury , a uniquely severe adverse experience, garnered significant public attention in the summer of 2019 when a case series of patients presenting with pulmonary illness associated with e-cigarette use was reported and an increasing number of hospitalizations occurred across the United States . Hospitalization admissions for EVALI peaked in September 2019 and declined through the end of that year. By the end of January 2020, 2,668 hospitalized EVALI cases were reported to the U.S. Centers for Disease Control and Prevention . Sixty-eight EVALI deaths have also been confirmed in the United States as of February 2020 . Tetrahydro cannabinol -containing products were highly associated with EVALI cases, with 82% of hospitalized patients using any THC containing vaping product, though 14% of hospitalized cases reported using only nicotine-containing products . Previous research suggests that among smokers, discontinuation of ecigarettes was attributed to factors related to product characteristics such as taste, not adequately resembling the smoking experience, or cost . Among former and never smoker young adults, however, feeling that e-cigarettes were bad for one’s health was shown to be a major reason for discontinuation of e-cigarettes, but being made sick from trying e-cigarettes was not . This suggests that adverse symptoms and health concerns may operate as distinct constructs among young adult former e-cigarette users. The possible distinction made between adverse symptoms and health concerns suggests that a more nuanced understanding of how young adult e-cigarette users process and respond to information about e-cigarette harm is needed. In the context of the EVALI outbreak and its impact on young adult e-cigarette users, it is unclear how the news and information about the disease affected current and future e-cigarette use attitudes and behavior. Hence, this study conducted an in-depth qualitative assessment of young adult e-cigarettes users’ understanding of and response to the EVALI outbreak. In Fall 2019, college students who use tobacco products on-campus were recruited from two four-year public universities in Southern California to participate in focus group discussions as part of a larger study on compliance with tobacco-free policies. Two marketing firms managed recruitment of participants and project logistics for focus groups which were held at off-campus facilities. One marketing firm was assigned to each university and utilized panels of potential participants, social media outreach, on-campus recruiting, and participant referral to recruit participants. In addition, research staff passed out study flyers to individuals observed smoking or vaping on-campus referring potential participants to marketing firms for study recruitment. Inclusion criteria for the larger study were: age 18 or older; student at one of the two universities; and self-reported use of a tobacco product on university property. Inclusion criteria of participants were verified by the market research companies and included participants furnishing university identification cards prior to assignment to focus groups held in October and November 2019. As this analysis focused on young adult populations, we excluded responses from participants older than 29 years of age and not being a current e-cigarette user. Upon arrival at the focus group facility, a study alias, informed consent materials, and a demographic and tobacco use questionnaire were given to each participant. Informed consent forms and demographic questionnaires could be completed prior to focus groups in the facility lobby, or after entering the focus group room if participants had questions. Free and informed consent was obtained from all participants. Seven mixed-gender focus groups were held, 3 with students from University 1 and 4 with students from University 2, with participants assigned to groups based on reported tobacco products used on campus. Groups had an average of 7.85 participants and average duration of 78.7 min . Focus groups were facilitated by the first author and followed a semi-structured protocol. Open ended questions regarding EVALI were “Can you describe to me when you first heard about EVALI and what your reaction was?” and “How did the news [about EVALI] affect your tobacco or ecigarette use?” with follow-up probes used to extract details about individual experiences, beliefs, and attitudes. Students who completed the focus group were given a $125 incentive for participation. Focus groups were recorded and verbatim transcripts were provided by the market research firms. The study protocol was approved by the Institutional Review Board at California State University, Fullerton . In 2020, focus group transcripts were reviewed for accuracy by research assistants then imported into and analyzed using Atlas.ti 8 qualitative data analysis software . The principal investigator developed an initial coding scheme based on the focus group discussion protocol and emergent themes from a close reading of a subset of two transcripts. Two research assistants coded a subset of focus group transcripts using the initial coding scheme and added new codes as needed.