Adolescent substance abuse: the effects of alcohol and marijuana on neuropsychological performance

Subjective time dilation in abstinent patients with alcohol use disorder

INTRODUCTION

Patients with alcohol use disorder (AUD) may have distortions in time perception. This study investigated subjective time dilation (the tendency to perceive a time interval longer than it is) and its association with craving and impulsivity in AUD.

METHOD

Thirty abstinent male inpatients with AUD (age 29-60 years) and thirty sex-, age-, and education-matched healthy controls completed a temporal generalization task, which assessed the preference (point of subjective equality, PSE) and sensitivity of time perception in the second range. Craving for alcohol was assessed using the Alcohol Urge Questionnaire. Impulsivity was assessed using a delay discounting task and the Barratt Impulsiveness Scale-11. A comprehensive battery of neuropsychological tests was used to measure executive function (flanker task, symbol digit modalities test, trail-making test-A/B), negative emotionality (Beck Depression Inventory-II, Self-rating Anxiety Scale), and incentive salience (monetary incentive delay task) following the Addictions Neuroclinical Assessment (ANA) framework.

RESULTS

AUD patients exhibited a smaller PSE than healthy controls, perceiving a time interval 8% longer than it was. AUD patients with a smaller PSE showed a greater craving for alcohol but not greater impulsivity. Exploratory factor analysis incorporating the PSE and ANA measures revealed four latent factors. The PSE loaded highly onto a factor reflecting time perception but not three other factors reflecting executive function, negative emotionality, and incentive salience.

CONCLUSIONS

AUD patients exhibit a pathological form of subjective time dilation, which is associated with a greater craving for alcohol. Time perception may be an independent functional dimension for understanding addictive behaviors in AUD.

The roles of extraversion and neuroticism in the relationship between childhood adversity and adolescent substance misuse

Although the influences of extraversion and neuroticism on the relationship between childhood adversity and substance misuse have been considered in adults, they are not yet clear and have not been examined among adolescent samples. This study sought to investigate the relationship between childhood adversity and adolescent substance misuse, alongside the influences of extraversion and neuroticism, using data from a longitudinal birth cohort study. Statistical analyses were performed on a longitudinal dataset provided by the Christchurch Health and Development Study (CHDS). After controlling for confounds, childhood adversity was a significant predictor of substance use disorder symptoms in adolescence. Moderation analyses showed that experiences of childhood adversity were most strongly associated with adolescent substance use disorder symptoms at higher levels of extraversion and at higher levels of neuroticism. Among adolescents who have experienced childhood adversity, extraversion and neuroticism may be risk factors for substance use disorder. By encouraging professionals to target adolescent substance misuse intervention and prevention approaches towards those who have experienced childhood adversity and are high in extraversion and/or neuroticism, these findings may help to diminish the prevalence of adolescent substance misuse and improve the health of adolescents.

Evaluation of the executive functions and quality of life in a sample of Egyptian male adolescents with substance use disorder: A case-control study

BACKGROUND

Adolescent substance use is a major problem that has serious medical, psychological, and legal consequences later in life. Substance use disorder is closely linked to deficits in executive functions. Impaired executive functions (EFs) have been linked to all stages of the substance use disorder (SUD) life cycle, increasing the likelihood of commencing use, escalating use more quickly, and increasing the likelihood of relapsing following treatment. The current study aimed at evaluating of the executive functions and quality of life in a sample of adolescent Egyptian males with substance use disorder.

RESULTS

A significantly higher mean Trail Making Test-A, B (TMT-A and TMT-B) scores among studied cases than the control group (equals lower executive functions) with a mean score of TMT-A is 74.38 versus 63.2 among controls and for TMT-B; the mean score for control is 97.22 versus 142.04 among cases. A statistically significant difference between the case and control groups on all quality of life scores measuring the following domains: general health and well-being, physical health, psychological health, social interactions, and the environment, also there has been a negative correlation between TMT-A and the environmental domain (r = - 0.279) and TMT-B with the same variable (r = - 0.414).

CONCLUSIONS

Substance use disorders are a major health problem among youth. Deficits in executive functions are strongly associated with adolescent substance use. The more affected executive functions are associated with more affected quality of life of these patients.

Effects of combined exposure to ethanol and delta-9-tetrahydrocannabinol during adolescence on synaptic plasticity in the prefrontal cortex of Long Evans rats

Significant exposure to alcohol or cannabis during adolescence can induce lasting disruptions of neuronal signaling in brain regions that are later to mature, such as the medial prefrontal cortex (mPFC). Considerably less is known about the effects of alcohol and cannabis co-use, despite its common occurrence. Here, we used male and female Long-Evans rats to investigate the effects of early-life exposure to ethanol, delta-9-tetrahydrocannabinol (THC), or their combination on high frequency stimulation (HFS)-induced plasticity in the prelimbic region of the mPFC. Animals were injected daily from postnatal days 30-45 with vehicle or THC (escalating doses, 3-20 mg/kg) and allowed to drink vehicle (0.1% saccharin) or 10% ethanol immediately after each injection. In vitro brain slice electrophysiology was then used to record population responses of layer V neurons following HFS in layer II/III after 3-4 weeks of abstinence. We found that THC exposure reduced body weight gains observed in ad libitum fed rats, and reduced intake of saccharin and ethanol. Compared to controls, there was a significant reduction in HFS-induced long-term depression (LTD) in rats exposed to either drug alone, and an absence of LTD in rats exposed to the drug combination. Bath application of indiplon or AR-A014418, which enhance GABAA receptor function or inhibit glycogen synthase kinase 3β (GSK3β), respectively, suggested the effects of ethanol, THC or their combination were due in part to lasting adaptations in GABA and GSK3β signaling. These results suggest the potential for long-lasting adaptations in mPFC output following co-exposure to alcohol and THC.

Effects of combined exposure to ethanol and delta-9-tetrahydrocannabinol during adolescence on synaptic plasticity in the prefrontal cortex of Long Evans rats

Significant exposure to alcohol or cannabis during adolescence can induce lasting disruptions of neuronal signaling in brain regions that are later to mature, such as the medial prefrontal cortex (mPFC). Considerably less is known about the effects of alcohol and cannabis co-use, despite its common occurrence. Here, we used male and female Long-Evans rats to investigate the effects of early-life exposure to ethanol, delta-9-tetrahydrocannabinol (THC), or their combination on high frequency stimulation (HFS)-induced plasticity in the prelimbic region of the mPFC. Animals were injected daily from postnatal days 30 to 45 with vehicle or THC (escalating doses, 3-20 mg/kg) and allowed to drink vehicle (0.1% saccharin) or 10% ethanol immediately after each injection. In vitro brain slice electrophysiology was then used to record population responses of layer V neurons following HFS in layer II/III after 3-4 weeks of abstinence. We found that THC exposure reduced body weight gains observed in ad libitum fed rats, and reduced intake of saccharin and ethanol. Compared to controls, there was a significant reduction in HFS-induced long-term depression (LTD) in rats exposed to either drug alone, and an absence of LTD in rats exposed to the drug combination. Bath application of indiplon or AR-A014418, which enhance GABAA receptor function or inhibit glycogen synthase kinase 3β (GSK3β), respectively, suggested the effects of ethanol, THC or their combination were due in part to lasting adaptations in GABA and GSK3β signaling. These results suggest the potential for long-lasting adaptations in mPFC output following co-exposure to alcohol and THC.

Interstrain differences in adolescent fear conditioning after acute alcohol exposure

Adolescent sensitivity to alcohol is a predictor of continued alcohol use and misuse later in life. Thus, it is important to understand the many factors that can impact alcohol sensitivity. Data from our laboratory suggested that susceptibility to alcohol-associated contextual fear learning deficits varied among adolescent and adult mice from two mouse strains. To investigate the extent of genetic background's influences on adolescent learning after alcohol exposure, we examined how 9 inbred mouse strains differed in vulnerability to alcohol-induced contextual and cued fear conditioning deficits. We demonstrated significant strain- and sex-dependent effects of acute alcohol exposure on adolescent fear learning, with alcohol having most pronounced effects on contextual fear learning. Female adolescents were more susceptible than males to alcohol-induced impairments in contextual, but not cued, fear learning, independent of genetic background. Heritability for contextual and cued fear learning after alcohol exposure was estimated to be 31 % and 18 %, respectively. Learning data were compared to Blood Ethanol Concentrations (BEC) to assess whether strain differences in alcohol metabolism contributed to strain differences in learning after alcohol exposure. There were no clear relationships between BEC and learning outcomes, suggesting that strains differed in learning outcomes for reasons other than strain differences in alcohol metabolism. Genetic analyses revealed polymorphisms across strains in notable genes, such as Chrna7, a promising genetic candidate for susceptibility to alcohol-induced fear conditioning deficits. These results are the first to demonstrate the impact of genetic background on alcohol-associated fear learning deficits during adolescence and suggest that the mechanisms underlying this sensitivity are distinct from alcohol metabolism.

Prevalence and correlates of alcohol-induced blackout in a diverse sample of veterans

BACKGROUND

Alcohol-induced blackouts have been associated concurrently and prospectively with alcohol-related harm. Although rates of heavy drinking among military samples tend to be comparable or higher than rates among civilian samples, the prevalence and correlates of blackout in the military population are understudied.

METHODS

Veterans (N = 241, 29% female, 39% Black) reported on their alcohol consumption and mental health as part of a larger health-related study among veterans. In this secondary analysis, we tested theoretically and empirically informed predictors (gender, drinking quantity, and other drug use) and consequences [depression, posttraumatic stress disorder (PTSD)] of alcohol-induced blackout. Given the diversity of the sample, potential roles of racial/ethnic discrimination and drinking to cope in alcohol-induced blackout were also tested.

RESULTS

Past-year prevalence of alcohol-induced blackout was 53% among veterans who drank alcohol and 68% among those who screened positive for hazardous drinking. Everyday experience of racial discrimination was the strongest concurrent predictor of alcohol-induced blackout. Drinking quantity and use of other drugs were significant correlates only in bivariate models. Controlling for gender, race, drinking quantity, other drug use, and discrimination, blackout frequency was significantly associated with symptoms of depression, but not symptoms of PTSD. Both blackout and racial discrimination were associated with drinking to cope.

CONCLUSIONS

The prevalence and correlates of alcohol-induced blackout among veterans are largely consistent with those documented in civilian and young adult populations. Among racially diverse groups, racial discrimination may be more strongly associated with mental health symptoms than alcohol consumption or acute alcohol consequences such as blackout.

Mesial Prefrontal Cortex and Alcohol Misuse: Dissociating Cross-sectional and Longitudinal Relationships in UK Biobank

BACKGROUND

Alcohol misuse is a major global public health issue. The disorder is characterized by aberrant neural networks interacting with environment and genetics. Dissecting the neural substrates and functional networks that relate to longitudinal changes in alcohol use from those that relate to alcohol misuse cross-sectionally is important to elucidate therapeutic approaches.

METHODS

To assess how neuroimaging data, including T1, resting-state functional magnetic resonance imaging, and diffusion-weighted imaging, relate to alcohol misuse cross-sectionally and longitudinally in the UK Biobank, this study analyzed range of alcohol misuse in a population-based normative sample of 24,784 participants, ages 45 to 81 years old, in a cross-sectional analysis and a sample of 3070 participants in a longitudinal analysis 2 years later.

RESULTS

Cross-sectional analysis showed that alcohol use is associated with a reduction in dorsal anterior cingulate cortex and dorsomedial prefrontal cortex gray matter concentration and functional resting-state connectivity (nodal degree: t_24,422 = -12.99, p < 1 × 10^-17). Reduced dorsal anterior cingulate cortex/dorsomedial prefrontal cortex functional connections to the ventrolateral prefrontal cortex, amygdala, and striatum relate to greater alcohol use. In a longitudinal analysis, higher resting-state nodal degree (t₃₀₃₆ = -3.27, p = .0011) and T1 gray matter concentration in the ventromedial prefrontal cortex relate to reduced alcohol intake frequency 2 years later. Higher ventromedial prefrontal cortex and frontoparietal executive network functional connectivity is associated with lower subsequent drinking longitudinally.

CONCLUSIONS

Dorsal versus ventromedial prefrontal regions are differentially related to alcohol misuse cross-sectionally or longitudinally in a large UK Biobank normative dataset. Our study provides a comprehensive understanding of the neurobiological substrates of alcohol use as a state or prospectively, thereby providing potential targets for clinical treatment.

The brain in social context: A systematic review of substance use and social processing from adolescence to young adulthood

Substance use escalates between adolescence and young adulthood, and most experimentation occurs among peers. To understand underlying mechanisms, research has focused on neural response during relevant psychological processes. Functional magnetic resonance imaging (fMRI) research provides a wealth of information about brain activity when processing monetary rewards; however, most studies have used tasks devoid of social stimuli. Given that adolescent neurodevelopment is sculpted by the push-and-pull of peers and emotions, identifying neural substrates is important for intervention. We systematically reviewed 28 fMRI studies examining substance use and neural responses to stimuli including social reward, emotional faces, social influence, and social stressors. We found substance use was positively associated with social-reward activity (e.g., in the ventral striatum), and negatively with social-stress activity (e.g., in the amygdala). For emotion, findings were mixed with more use linked to heightened response (e.g., in amygdala), but also with decreased response (e.g., in insula). For social influence, evidence supported both positive (e.g., cannabis and nucleus accumbens during conformity) and negative (e.g., polydrug and ventromedial PFC during peers' choices) relations between activity and use. Based on the literature, we offer recommendations for future research on the neural processing of social information to better identify risks for substance use.

Do interventions principally targeting excessive alcohol use in young people improve depression symptoms?: a systematic review and meta-analysis

BACKGROUND

Excessive alcohol use is common in young people and is associated with a range of adverse consequences including an increased risk of depression. Alcohol interventions are known to be effective in young people, however it is not known if these interventions can also improve depression.

OBJECTIVE

To investigate whether psychosocial interventions principally targeting excessive alcohol use in young people reduce depression symptoms compared to controls.

DESIGN

We conducted a systematic review and meta-analysis of controlled intervention trials, that measured depression symptoms at follow-up. We used a generic inverse variance random effect meta-analysis to pool the standardised mean difference in change in depression symptoms from baseline to follow-up between intervention and control arms. We used I² to measure heterogeneity, the Cochrane tool for randomised trials to assess risk of bias, and Egger's tests to assess small study bias.

DATA SOURCES

APA PsycNET, PubMed, Cochrane Central Register of Controlled Trials, Web of Science, Embase (including MEDLINE), and clinicaltrials.gov were searched for relevant studies published from inception to December 2020. Reference lists of studies were also searched, and authors contacted where articles presented insufficient data.

STUDY ELIGIBILITY CRITERIA

Intervention studies that primarily targeted existing excessive alcohol use in young people (aged 10 to 24) and assessed depression outcomes at baseline with a minimum of four-week follow-up.

RESULTS

Five studies were included in the meta-analysis. Interventions targeting excessive alcohol use were associated with a reduction in depression symptoms from baseline to follow-up when compared to control, standardised mean difference = - 0.26, and 95% confidence interval [- 0.41, - 0.12], p < .001.

CONCLUSIONS

This study found evidence that interventions primarily targeting excessive alcohol use can reduce depression symptoms in young people. However, this finding should be taken with caution given concerns about risk of bias in all studies. More research is needed to examine whether these findings generalise beyond populations of undergraduate students primarily living in high income countries.

TRIAL REGISTRATION

PROSPERO registration number: CRD42020177260 .

Marijuana use and high-risk health behaviors among diverse college students post- legalization of recreational marijuana use

Objectives

This study examined high-risk health behaviors in marijuana-users among a diverse college population in Southern California, post legalization of marijuana for recreational use.

Study design

A cross-sectional research design was employed utilizing existing data via the 2018 National College Health Assessment (NCHA) from a large Minority-Serving Institution (MSI) population [n = 1345 (Hispanic/Latino/a, n = 456; White, n = 353; Asian Pacific Islander (API), n = 288; Multiracial/Biracial, n = 195; Other, n = 53)].

Methods

Chi square and t-tests assessed differences in descriptive characteristics (age, gender, race/ethnicity and GPA) and high-risk behaviors (alcohol, tobacco and sexual behaviors) among marijuana users and non-users. Logistic regression analyses examined the relationship between race/ethnicity and high-risk behaviors with marijuana use (dependent variable).

Results

Among marijuana-users, significant (p = 0.004) differences were observed between race/ethnicity with Whites reporting using most (32.7%), followed by Hispanics (27.6%) and then APIs (17.8%). Marijuana-users compared with non-users consistently reported high-risk alcohol behaviors (p < 0.0001), were more likely to smoke tobacco (p < 0.0001) and engaged in more high-risk sexual behaviors (p < 0.0001). Logistic regression showed after adjusting for demographic characteristics and high-risk behaviors, race/ethnicity was borderline significantly associated with marijuana use, specifically for Whites (OR = 1.53; 95% CI: (−0.01, 0.86), p = 0.06) and the Other race/ethnicity category (OR = 2.32; 95% CI: (0.12, 1.56), p = 0.02) compared with APIs.

Conclusion

Our findings clearly demonstrate deleterious high-risk behaviors such as alcohol use, tobacco use, and certain sexual behaviors occur more among marijuana-users compared to non-users, post legalization of marijuana for recreational use. Further, race-ethnic differences were observed. Therefore, continued examination of marijuana use trends and high-risk behaviors is critical in monitoring the implications of marijuana policy changes, specifically in diverse populations.

The Effects of Alcohol and Cannabis Co-Use on Neurocognitive Function, Brain Structure, and Brain Function

Purpose of review

Given increases in the rates of alcohol and cannabis co-use among adolescents and young adults, this review aims to summarize literature on the effects of alcohol and cannabis co-use on neurocognitive functioning, brain structure, and brain function.

Recent findings

The limited existing studies examining concurrent, recent, and lifetime alcohol and cannabis co-use suggest effects on the brain are likely multifaceted. The majority of studies report that co-use is associated with negative outcomes such as impaired cognitive function and significant alterations in key structural and functional regions of the brain, while others report null effects of co-use compared to non-substance using control and single-substance use groups.

Summary

Current studies lack a general consensus on methodology, definitions of concurrent and simultaneous use, and neuroimaging approaches, which makes it challenging to draw strong conclusions about the effects of co-use. More studies are needed to explore the effects of co-use in the context of simultaneous alcohol and cannabis use.

Effects of repeated adolescent exposure to cannabis smoke on cognitive outcomes in adulthood

BACKGROUND

Cannabis (marijuana) is the most widely used illicit drug in the USA, and consumption among adolescents is rising. Some animal studies show that adolescent exposure to delta 9-tetrahydrocannabinol or synthetic cannabinoid receptor 1 agonists causes alterations in affect and cognition that can persist into adulthood. It is less clear, however, whether similar alterations result from exposure to cannabis via smoke inhalation, which remains the most frequent route of administration in humans.

AIMS

To begin to address these questions, a rat model was used to determine how cannabis smoke exposure during adolescence affects behavioral and cognitive outcomes in adulthood.

METHODS

Adolescent male Long-Evans rats were assigned to clean air, placebo smoke, or cannabis smoke groups. Clean air or smoke exposure sessions were conducted daily during adolescence (from P29-P49 days of age ) for a total of 21 days, and behavioral testing began on P70.

RESULTS

Compared to clean air and placebo smoke conditions, cannabis smoke significantly attenuated the normal developmental increase in body weight, but had no effects on several measures of either affect/motivation (open field activity, elevated plus maze, instrumental responding under a progressive ratio schedule of reinforcement) or cognition (set shifting, reversal learning, intertemporal choice). Surprisingly, however, in comparison to clean air controls rats exposed to either cannabis or placebo smoke in adolescence exhibited enhanced performance on a delayed response working memory task.

CONCLUSIONS

These findings are consistent with a growing body of evidence for limited long-term adverse cognitive and affective consequences of adolescent exposure to relatively low levels of cannabinoids.

Clinical and social factors associated with involuntary psychiatric hospitalisation in children and adolescents: a systematic review, meta-analysis, and narrative synthesis

BACKGROUND

Disparities in involuntary psychiatric hospitalisation between population subgroups have been identified in adults, but little is known about the factors associated with involuntary hospitalisation in children or adolescents. We did a systematic review, meta-analysis, and narrative synthesis to investigate the social and clinical factors associated with involuntary psychiatric hospitalisation among children and adolescents.

METHODS

We searched MEDLINE, PsycINFO, Embase, and the Cochrane Central Register of Controlled Trials for studies of any type up to July 22, 2020, that compared the characteristics of voluntary and involuntary psychiatric inpatients (mean age of sample ≤18 years). We synthesised results using random effects meta-analysis on unadjusted data and by narrative synthesis. Heterogeneity between studies was calculated using I2. This study is registered on PROSPERO, CRD42020099892.

FINDINGS

23 studies from 11 countries were included in the systematic review and narrative synthesis, of which 19 studies (n=31 212) were included in the meta-analysis. On meta-analysis, involuntary rather than voluntary hospitalisation of minors was associated with a diagnosis of psychosis (eight studies; odds ratio 3·63, 95% CI 2·43-5·44, p<0·0001), substance misuse (five studies; 1·87, 1·05-3·30, p=0·032), or intellectual disability (four studies; 3·33, 1·33-8·34, p=0·010), as well as presenting with a perceived risk of harm to self (eight studies; 2·05, 1·15-3·64, p=0·015) or to others (five studies; 2·37, 1·39-4·03, p=0·0015). Involuntary hospitalisation was also found to be associated with being aged 12 years or older (three studies; 3·57, 1·46-8·73, p=0·0052) and being from a Black rather than a White ethnic group (three studies; 2·72, 1·88-3·95, p<0·0001). There was substantial between-study heterogeneity for most factors included in the meta-analysis (I2 from 51·3% to 92·3%). Narrative synthesis found that more severe illness and poorer global functioning was associated with involuntary hospitalisation.

INTERPRETATION

Over-representation of involuntary psychiatric hospitalisation in certain groups might begin in childhood, potentially establishing a cycle of inequality that continues into adulthood. Further research into the systemic factors underlying these health-care inequalities and the barriers to accessing less coercive psychiatric treatment is urgently required, with specific consideration of racial and ethnic factors.

FUNDING

UK National Institute for Health Research and Wellcome Trust.

Linking RDoC and HiTOP: A new interface for advancing psychiatric nosology and neuroscience

The Research Domain Criteria (RDoC) and the Hierarchical Taxonomy of Psychopathology (HiTOP) represent major dimensional frameworks proposing two alternative approaches to accelerate progress in the way psychopathology is studied, classified, and treated. RDoC is a research framework rooted in neuroscience aiming to further the understanding of transdiagnostic biobehavioral systems underlying psychopathology and ultimately inform future classifications. HiTOP is a dimensional classification system, derived from the observed covariation among symptoms of psychopathology and maladaptive traits, which seeks to provide more informative research and treatment targets (i.e., dimensional constructs and clinical assessments) than traditional diagnostic categories. This article argues that the complementary strengths of RDoC and HiTOP can be leveraged in order to achieve their respective goals. RDoC's biobehavioral framework may help elucidate the underpinnings of the clinical dimensions included in HiTOP, whereas HiTOP may provide psychometrically robust clinical targets for RDoC-informed research. We present a comprehensive mapping between dimensions included in RDoC (constructs and subconstructs) and HiTOP (spectra and subfactors) based on narrative review of the empirical literature. The resulting RDoC-HiTOP interface sheds light on the biobehavioral correlates of clinical dimensions and provides a broad set of dimensional clinical targets for etiological and neuroscientific research. We conclude with future directions and practical recommendations for using this interface to advance clinical neuroscience and psychiatric nosology. Ultimately, we envision that this RDoC-HiTOP interface has the potential to inform the development of a unified, dimensional, and biobehaviorally-grounded psychiatric nosology.

Impact of 2 Weeks of Monitored Abstinence on Cognition in Adolescent and Young Adult Cannabis Users

OBJECTIVES

Previous research suggests recovery from cannabis-related deficits in verbal learning and memory functioning after periods of cannabis abstinence in adolescents. Here, we examine how cannabis cessation affects cognitive performance over 2 weeks of monitored abstinence compared to controls in adolescents and young adults.

METHODS

Seventy-four participants (35 cannabis users) aged 16-26 ceased all cannabis, alcohol, and other illicit substance consumption for a 2-week period; abstinence was monitored via weekly urinalysis, breath, and sweat patch testing. Starting at baseline, participants completed weekly abbreviated neuropsychological batteries. Measures included tests of attention, inhibition, verbal working memory, and learning. Repeated measures assessed within and between subject effects for time and group status, while controlling for past year alcohol and nicotine use.

RESULTS

Cannabis users showed increased performance compared to controls on sustained attention tasks after 2 weeks of cannabis use.

CONCLUSIONS

Deficits in attention, but not verbal learning and memory, recovered after 2 weeks of monitored abstinence. This differs from previous literature, suggesting that other cognitive domains may show signs of recovery after periods of cannabis cessation in adolescents and young adults.

Selective breeding for high alcohol preference is associated with increased sensitivity to cannabinoid reward within the nucleus accumbens shell

RATIONALE

The rate of cannabinoid intake by those with alcohol use disorder (AUD) exceeds that of the general public. The high prevalence of co-abuse of alcohol and cannabis has been postulated to be predicated upon both a common predisposing genetic factor and the interaction of the drugs within the organism. The current experiments examined the effects of cannabinoids in an animal model of AUD.

OBJECTIVES

The present study assessed the reinforcing properties of a cannabinoid receptor 1 (CB1) agonist self-administered directly into the nucleus accumbens shell (AcbSh) in female Wistar and alcohol-preferring (P) rats.

METHODS

Following guide cannulae surgery aimed at AcbSh, subjects were placed in an operant box equipped with an 'active lever' (fixed ratio 1; FR1) that caused the delivery of the infusate and an 'inactive lever' that did not. Subjects were arbitrarily assigned to one of seven groups that self-administered either artificial cerebrospinal fluid (aCSF), or 3.125, 6.25, 12.5, or 25 pmol/100 nl of O-1057, a water-soluble CB1 agonist, dissolved in aCSF. The first four sessions of acquisition are followed by aCSF only infusates in sessions 5 and 6 during extinction, and finally the acquisition dose of infusate during session 7 as reinstatement.

RESULTS

The CB1 agonist was self-administered directly into the AcbSh. P rats self-administered the CB1 agonist at lower concentrations and at higher rates compared to Wistar rats.

CONCLUSIONS

Overall, the data indicate selective breeding for high alcohol preference has produced rats divergent in response to cannabinoids within the brain reward pathway. The data support the hypothesis that there can be common genetic factors influencing drug addiction.

The effects of adolescent alcohol exposure on learning and related neurobiology in humans and rodents

Adolescent alcohol use is a widespread problem in the United States. In both humans and rodents, alcohol can impair learning and memory processes mediated by forebrain areas such as the prefrontal cortex (PFC) and hippocampus (HC). Adolescence is a period in which alcohol use often begins, and it is also a time that can be uniquely sensitive to the detrimental effects of alcohol. Exposure to alcohol during adolescence can cause persisting alterations in PFC and HC neurobiology that are linked to cognitive impairments, including changes in neurogenesis, inflammation, and various neurotransmitter systems in rodent models. Consistent with this, chronic adolescent alcohol exposure can cause PFC-dependent learning impairments that persist into adulthood. Deficits in adult HC-dependent learning after adolescent alcohol exposure have also been reported, but these findings are less consistent. Overall, evidence summarized in this review indicates that adolescent exposure to alcohol can produce long-term detrimental effects on forebrain-dependent cognitive processes.

Neuropsychological Trajectories Associated with Adolescent Alcohol and Cannabis Use: A Prospective 14-Year Study

OBJECTIVES

Alcohol and cannabis remain the substances most widely used by adolescents. Better understanding of the dynamic relationship between trajectories of substance use in relation to neuropsychological functioning is needed. The aim of this study was to examine the different impacts of within- and between-person changes in alcohol and cannabis use on neuropsychological functioning over multiple time points.

METHODS

Hierarchical linear modeling examined the effects of alcohol and cannabis use on neuropsychological functioning over the course of 14 years in a sample of 175 adolescents (aged 12-15 years at baseline).

RESULTS

Time-specific fluctuations in alcohol use (within-person effect) predicted worse performance across time on the Wechsler Abbreviated Scale of Intelligence Block Design subtest (B = -.05, SE = .02, p = .01). Greater mean levels of percent days of cannabis use across time (between-person effect) were associated with an increased contrast score between Delis-Kaplan Executive Function System Color Word Inhibition and Color Naming conditions (B = .52, SE = .14, p < .0001) and poorer performance over time on Block Design (B = -.08, SE = .04, p = .03). Neither alcohol and/nor cannabis use over time was associated with performance in the verbal memory and processing speed domains.

CONCLUSIONS

Greater cumulative cannabis use over adolescence may be linked to poorer inhibitory control and visuospatial functioning performance, whereas more proximal increases in alcohol consumption during adolescence may drive alcohol-related performance decrements in visuospatial functioning. Results from this prospective study add to the growing body of literature on the impact of alcohol and cannabis use on cognition from adolescent to young adulthood.

Cannabis use and nonuse in patients with first-episode psychosis: A systematic review and meta-analysis of studies comparing neurocognitive functioning

BACKGROUND

The implications of cannabis use in the onset of early psychosis and the severity of psychotic symptoms have resulted in a proliferation of studies on this issue. However, few have examined the effects of cannabis use on the cognitive symptoms of psychosis (i.e., neurocognitive functioning) in patients with first-episode psychosis (FEP). This systematic review and meta-analysis aim to assess the neurocognitive functioning of cannabis users (CU) and nonusers (NU) with FEP.

METHODS

Of the 110 studies identified through the systematic review of 6 databases, 7 met the inclusion criteria, resulting in 14 independent samples and 78 effect sizes. The total sample included 304 CU with FEP and 369 NU with FEP. The moderator variables were age at first use, duration of use, percentage of males, and age.

RESULTS

Effect sizes were not significantly different from zero in any neurocognitive domain when users and NU were compared. Part of the variability in effect sizes was explained by the inclusion of the following moderator variables: (1) frequency of cannabis use (β = 0.013, F = 7.56, p = 0.017); (2) first-generation antipsychotics (β = 0.019, F = 34.46, p ≤ 0.001); and (3) country where the study was carried out (β = 0.266, t = 2.06, p = 0.043).

CONCLUSIONS

This meta-analysis indicates that cannabis use is not generally associated with neurocognitive functioning in patients with FEP. However, it highlights the deleterious effect of low doses of cannabis in some patients. It also stresses the importance of the type of antipsychotic prescription and cannabis dose as moderator variables in the neurocognitive functioning of CU with FEP.

Brain activation to cannabis- and alcohol-related words in alcohol use disorder

Cannabis abuse commonly co-occurs with alcohol use disorder (AUD). With increased acceptance and accessibility to cannabis in the US, it is imperative to understand the psychological and neural mechanisms of concurrent alcohol and cannabis use. We hypothesized that neural alcohol-cue conditioning may extent to other drug-related stimuli, such as cannabis, and underwrite the loss of control over reward-driven behavior. Task-activated fMRI examined the neural correlates of alcohol- and cannabis-related word cues in 21 abstinent AUD and 18 control subjects. Relative to controls, AUD showed behavioral attentional biases and frontal hypoactivation to both alcohol- and cannabis-related words. This cue-elicited prefrontal hypoactivation was related to higher lifetime alcohol consumption (pcorrected < 0.02) and modulated by past cannabis use histories (p ≦ 0.001). In particular, frontal hypoactivation to both alcohol and cannabis cues was pronounced in AUD without prior cannabis exposure. Overall, frontal control mechanisms in abstinent AUD were not sufficiently engaged to override automatic alcohol and cannabis-related intrusions, enhancing the risk for relapse and potentially for alcohol and cannabis co-use with the increased social acceptance and accessibility in the US.

Assessing the association between the strength of state policies on school drug prevention and substance use disorders

BACKGROUND

Adolescent substance use has been linked to numerous adverse health, social, and educational outcomes. While there have been intensive resources placed in school-based prevention programs, the association of these policies on prevention outcomes is still unclear. State variation in policies provides an opportunity to assess the influence of school-based prevention programs.

OBJECTIVES

To examine the association between the strength of state high school-based prevention programing and the prevalence of substance use disorders among adolescents ages 14-17 in the United States.

METHODS

National Survey on Drug Use and Health (NSDUH) data with state-level identifiers were merged with National Association of State Boards of Education (NASBE) information on school-based prevention policy strength, categorized into "required," "recommended," and "no policy." Unadjusted comparisons and multilevel random intercept linear regression models were estimated to assess the change in rates of substance abuse or dependence from pre- to post- policy implementation, accounting for the nesting of individuals within states.

RESULTS

Rates of alcohol and tobacco abuse/dependence were significantly lower in states that required an alcohol prevention curriculum. After covariate adjustment, rates of alcohol abuse/dependence remained significantly lower in those states.

CONCLUSIONS

Reinforcing alcohol prevention messaging in school appears to have a modest association with decreased rates of adolescent alcohol use disorders, possibly in part due to a different approach to the curriculum. For other substances, policy requirements appear to be less effective in reducing the prevalence of adolescent substance use disorders, suggesting that more targeted messaging with higher-risk students may be required.

Vulnerability or resilience to early substance use among adolescents at risk: The roles of maltreatment and father involvement

Although research has indicated that maltreated children are at higher risk of adolescent substance use, it remains unclear whether the type and timing of maltreatment affect the likelihood of adolescent substance use. Research has also found father involvement to be a potential protective factor against adolescent substance use, but the role of quality vs. quantity of father involvement as well as gender differences in the effects of father involvement on substance use among at-risk adolescents have not been studied. The current study adds value to the existing literature by filling these gaps in knowledge. We conducted a secondary data analysis with a sample of 685 at-risk adolescents drawn from the Longitudinal Studies of Child Abuse and Neglect. The study found a connection between early childhood (birth to 5) physical abuse and adolescent substance use, but not for later childhood physical abuse or other forms of child maltreatment. The quality of father involvement was found to be a protective factor, regardless of child gender; quantity of father involvement was not significant. Based on these findings, development of intervention strategies focusing on prevention of early childhood physical abuse and promoting positive father-child relationships are important prevention strategies for adolescent substance use. Additionally, professionals working with at-risk adolescents need to be cognizant of the implications of early childhood physical abuse and act accordingly to mitigate the increased potential for adolescent substance use.

One Month of Cannabis Abstinence in Adolescents and Young Adults Is Associated With Improved Memory

OBJECTIVE

Associations between adolescent cannabis use and poor neurocognitive functioning have been reported from cross-sectional studies that cannot determine causality. Prospective designs can assess whether extended cannabis abstinence has a beneficial effect on cognition.

METHODS

Eighty-eight adolescents and young adults (aged 16-25 years) who used cannabis regularly were recruited from the community and a local high school between July 2015 and December 2016. Participants were randomly assigned to 4 weeks of cannabis abstinence, verified by decreasing 11-nor-9-carboxy-∆⁹-tetrahydrocannabinol urine concentration (MJ-Abst; n = 62), or a monitoring control condition with no abstinence requirement (MJ-Mon; n = 26). Attention and memory were assessed at baseline and weekly for 4 weeks with the Cambridge Neuropsychological Test Automated Battery.

RESULTS

Among MJ-Abst participants, 55 (88.7%) met a priori criteria for biochemically confirmed 30-day continuous abstinence. There was an effect of abstinence on verbal memory (P = .002) that was consistent across 4 weeks of abstinence, with no time-by-abstinence interaction, and was driven by improved verbal learning in the first week of abstinence. MJ-Abst participants had better memory overall and at weeks 1, 2, 3 than MJ-Mon participants, and only MJ-Abst participants improved in memory from baseline to week 1. There was no effect of abstinence on attention: both groups improved similarly, consistent with a practice effect.

CONCLUSIONS

This study suggests that cannabis abstinence is associated with improvements in verbal learning that appear to occur largely in the first week following last use. Future studies are needed to determine whether the improvement in cognition with abstinence is associated with improvement in academic and other functional outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03276221.

College student knowledge of blackouts and implications for alcohol intervention: A qualitative analysis

Blackouts (periods of alcohol-induced anterograde amnesia) are common among young adults and place individuals at significant risk for alcohol-related harm; thus, researchers have advocated for increased efforts to educate young adults on blackouts. This qualitative study examined college student knowledge of blackouts as well as their ideas for intervening on blackout drinking behavior in order to inform prevention and intervention efforts. College students who had experienced a blackout in the past 6 months participated in eight focus groups, stratified by gender (N = 50, five to eight/group, 56% female). Discussions followed a semistructured agenda. Audio recordings were transcribed verbatim and coded using applied thematic analysis. Themes related to knowledge were reviewed in comparison to the empirical literature. Empirically derived risk factors for blackouts included biology (e.g., genetics, biological sex), drinking behavior (i.e., rate of consumption), other drug use, and "indirect" influences (e.g., pregaming, drinking location). Participants' knowledge of the risk factors for blackout was inconsistent and, in some cases, inaccurate. While participants generally understood the behavioral risk factors for blackouts, they demonstrated less understanding of the role of genetics, biological sex, drinking speed (vs. quantity), and other drug use. They also identified dehydration and sleep as perceived risk factors for blackout. They suggested avenues for intervention at the policy (e.g., amnesty policies), peer (e.g., expressing concern), and individual (e.g., education) levels. College students with a history of blackout have limited understanding of the biological risk factors for blackout. These knowledge gaps represent targets for intervention. Findings indicate promise for blackout-specific interventions. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Recovery schools for improving behavioral and academic outcomes among students in recovery from substance use disorders: a systematic review

This Campbell systematic review examines the effects of recovery schools on student behavioral and academic outcomes, compared to the effects of non-recovery schools. The review summarizes evidence from one quasi-experimental study (with a total of 194 participants) that had potential serious risk of bias due to confounding. Sizable portions of youth are in recovery from substance use disorders, and many youth will return to use after receiving substance use treatment. Youth spend most of their waking hours at school, and thus schools are important social environments for youth in recovery from substance use disorders. Recovery schools have been identified as educational programs that may help support youth in recovery from substance use disorders. This review focused on two types of recovery schools: RHSs, which are schools that award secondary school diplomas and offer a range of therapeutic services in addition to standard educational curricula; and CRCs, which offer therapeutic and sober support services on college campuses. This review looked at whether recovery schools (RHSs or CRCs) affect academic success and substance use outcomes among students, compared to similar students who are not enrolled in recovery schools.

Plain language summary

There is insufficient evidence to know whether recovery high schools and collegiate recovery communities are effective: Evidence that recovery high schools (RHSs) may improve academic and substance use outcomes is based on the findings from a single study with a serious risk of bias.The review in brief: Very limited evidence addresses the effectiveness of recovery high schools (RHSs). There is no rigorous evidence on the effectiveness of collegiate recovery communities (CRCs).It is unclear whether CRCs are effective in promoting academic success and reducing substance use among college students.What is the aim of this review?: This Campbell systematic review examines the effects of recovery schools on student behavioral and academic outcomes, compared to the effects of non-recovery schools. The review summarizes evidence from one quasi-experimental study (with a total of 194 participants) that had potential serious risk of bias due to confounding.What are the main findings of this review?: Sizable portions of youth are in recovery from substance use disorders, and many youth will return to use after receiving substance use treatment. Youth spend most of their waking hours at school, and thus schools are important social environments for youth in recovery from substance use disorders. Recovery schools have been identified as educational programs that may help support youth in recovery from substance use disorders.This review focused on two types of recovery schools: RHSs, which are schools that award secondary school diplomas and offer a range of therapeutic services in addition to standard educational curricula; and CRCs, which offer therapeutic and sober support services on college campuses.This review looked at whether recovery schools (RHSs or CRCs) affect academic success and substance use outcomes among students, compared to similar students who are not enrolled in recovery schools.What studies are included?: The included study of recovery high schools used a controlled quasi-experimental pretest-posttest design and reported on the following outcomes: grade point average, truancy, school absenteeism, alcohol use, marijuana use, other drug use, and abstinence from alcohol/drugs. The included study focused on a sample of U.S. high school students. There were no eligible studies of CRCs.What do the findings of this review mean?: Findings from this review indicate insufficient evidence on the effects of recovery schools on student well-being. Although there is some indication RHSs may improve academic and substance use outcomes, this is based on the findings from a single study. There is no available evidence on the effects of CRCs.No strong conclusions can be drawn at this time, given the lack of available evidence on RHSs and CRCs, and the serious risk of bias in the one RHS study included in the review. The evidence from this review suggests there is a clear need for additional rigorous evaluations of recovery school effects prior to widespread implementation.How up-to-date is this review?: The review authors searched for studies until September 2018. This Campbell systematic review was published in 2018.

Executive Summary/Abstract

BACKGROUND: Substance use disorders (SUDs) among youth are a major public health problem. In the United States, for example, the incidence of SUDs increases steadily after age 12 and peaks among youth ages 18-23 (White, Evans, Ali, Achara-Abrahams, & King, 2009). Although not every youth who experiments with alcohol or illicit drugs is diagnosed with an SUD, approximately 7-9% of 12-24 year olds in the United States were admitted for public SUD treatment in 2013 (Substance Abuse and Mental Health Services Administration [SAMHSA], 2016). Recovery from an SUD involves reduction or complete abstinence of use, defined broadly as "voluntarily sustained control over substance use, which maximises health and wellbeing and participation in the rights, roles and responsibilities of society" (UK Drug Policy Commission, 2008). However, SUDs are often experienced as chronic conditions; among youth who successfully complete substance use treatment, approximately 45-70% return to substance use within months of treatment discharge (Anderson, Ramo, Schulte, Cummins, & Brown, 2007; Brown, D'Amico, McCarthy, & Tapert, 2001; Ramo, Prince, Roesch, & Brown, 2012; White et al., 2004). Thus, multiple treatment episodes and ongoing recovery supports after treatment are often necessary to assist with the recovery process (Brown et al., 2001; Ramo et al., 2012; White et al., 2004).Success and engagement at school and in postsecondary education are critical to healthy youth development. For youth in recovery from SUDs, school attendance, engagement, and achievement build human capital by motivating personal growth, creating new opportunities and social networks, and increasing life satisfaction and meaning (Keane, 2011; Terrion, 2012; 2014). Upon discharge from formal substance use treatment settings, schools become one of the most important social environments in the lives of youth with SUDs. Healthy school peer environments can enable youth to replace substance use behaviors and norms with healthy activities and prosocial, sober peers. Conversely, many school environments may be risky for youth in recovery from SUDs due to perceived substance use among peers, availability of drugs or alcohol, and substance-approving norms on campus (Centers for Disease Control [CDC], 2011; Spear & Skala, 1995; Wambeam, Canen, Linkenbach, & Otto, 2014).Given the many social and environmental challenges faced by youth in recovery from substance use, recovery-specific institutional supports are increasingly being linked to educational settings. The two primary types of education-based continuing care supports for youth in recovery, defined under the umbrella term of "recovery schools" for this review, are recovery high schools (RHSs) and collegiate recovery communities (CRCs). RHSs are secondary schools that provide standard high school education and award secondary school diplomas, but also include therapeutic programming aimed at promoting recovery (e.g., group check-ins, community service, counseling sessions). CRCs also provide recovery oriented support services (e.g., self-help groups, counseling sessions, sober dorms) for students, but are embedded within larger college or university settings. The primary aims of RHSs and CRCs are to promote abstinence and prevent relapse among students, and thus ultimately improve students' academic success.OBJECTIVES: This review summarized and synthesized the available research evidence on the effects of recovery schools for improving academic success and behavioural outcomes among high school and college students who are in recovery from substance use. The specific research questions that guided the review are as follows: 1. What effect does recovery school attendance (versus attending a non-recovery or traditional school setting) have on academic outcomes for students in recovery from substance use? Specifically (by program type): a. For recovery high schools: what are the effects on measures of academic achievement, high school completion, and college enrolment?b. For collegiate recovery communities: what are the effects on measures of academic achievement and college completion?2. What effect does recovery school attendance have on substance use outcomes for students in recovery from substance use? Specifically, what are the effects on alcohol, marijuana, cocaine, or other substance use?3. Do the effects of recovery schools on students' outcomes vary according to the race/ethnicity, gender, or socioeconomic status of the students?4. Do the effects of recovery schools on students' outcomes vary according to existing mental health comorbidity status or juvenile justice involvement of the students? SEARCH METHODS: We aimed to identify all published and unpublished literature on recovery schools by using a comprehensive and systematic literature search. We searched multiple electronic databases, research registers, grey literature sources, and reference lists from prior reviews; and contacted experts in the field.SELECTION CRITERIA: Studies were included in the review if they met the following criteria:Types of studies: Randomized controlled trial (RCT), quasi-randomized controlled trial (QRCT), or controlled quasi-experimental design (QED).Types of participants: Students in recovery from substance use who were enrolled part-time or full-time in secondary (high school) or postsecondary (college or university) educational institutions.Types of interventions: Recovery schools broadly defined as educational institutions, or programs at educational institutions, developed specifically for students in recovery and that address recovery needs in addition to academic development.Types of comparisons: Traditional educational programs or services that did not explicitly have a substance use recovery focus.Types of outcome measures: The review focused on primary outcomes in the following two domains: academic performance (e.g., achievement test scores, grade-point average, high school completion, school attendance, college enrolment, college completion) and substance use (alcohol, marijuana, cocaine, heroin, stimulant, mixed drug use, or other illicit drug use). Studies that met all other eligibility criteria were considered eligible for the narrative review portion of this review even if they did not report outcomes in one of the primary outcome domains.Other criteria: Studies must have been reported between 1978 and 2016. The search was not restricted by geography, language, publication status, or any other study characteristic.DATA COLLECTION AND ANALYSIS: Two reviewers independently screened all titles and abstracts of records identified in the systematic search. Records that were clearly ineligible or irrelevant were excluded at the title/abstract phase; all other records were retrieved in full-text and screened for eligibility by two independent reviewers. Any discrepancies in eligibility assessments were discussed and resolved via consensus. Studies that met the inclusion criteria were coded by two independent reviewers using a structured data extraction form; any disagreements in coding were resolved via discussion and consensus. If members of the review team had conducted any of the primary studies eligible for the review, external and independent data collectors extracted data from those studies. Risk of bias was assessed using the ROBINS-I tool for non-randomized study designs (Sterne, Higgins, & Reeves, 2016).Inverse variance weighted random effects meta-analyses were planned to synthesize effect sizes across studies, as well as heterogeneity analysis, subgroup analysis, sensitivity analysis, and publication bias analysis. However, these synthesis methods were not used given that only one study met the inclusion criteria for the review. Instead, effect sizes (and their corresponding 95% confidence intervals) were reported for all eligible outcomes reported in the study.RESULTS: Only one study met criteria for inclusion in the review. This study used a QED to examine the effects of RHSs on high school students' academic and substance use outcomes. No eligible studies examining CRCs were identified in the search.The results from the one eligible RHS study indicated that after adjusting for pretest values, students in the RHS condition reported levels of grade point averages (= 0.26, 95% CI [-0.04, 0.56]), truancy (= 0.01, 95% CI [-0.29, 0.31]), and alcohol use (= 0.23, 95% CI [-0.07, 0.53]) similar to participants in the comparison condition. However, students in the RHS condition reported improvements in absenteeism (= 0.56, 95% CI [0.25, 0.87]), abstinence from alcohol/drugs (OR = 4.36, 95% CI [1.19, 15.98]), marijuana use (= 0.51, 95% CI [0.20, 0.82]), and other drug use (= 0.45, 95% CI [0.14, 0.76]).Overall, there was a serious risk of bias in the one included study. The study had a serious risk of bias due to confounding, low risk of bias due to selection of participants into the study, moderate risk of bias due to classification of interventions, inconclusive risk of bias due to deviations from intended interventions, inconclusive risk of bias due to missing data, moderate risk of bias in measurement of outcomes, and low risk of bias in selection of reported results.AUTHORS' CONCLUSIONS: There is insufficient evidence regarding the effectiveness of RHSs and CRCs for improving academic and substance use outcomes among students in recovery from SUDs. Only one identified study examined the effectiveness of RHSs. Although the study reported some beneficial effects, the results must be interpreted with caution given the study's potential risk of bias due to confounding and limited external validity. No identified studies examined the effectiveness of CRCs across the outcomes of interest in this review, so it is unclear what effects these programs may have on students' academic and behavioral outcomes.The paucity of evidence on the effectiveness of recovery schools, as documented in this review, thus suggest the need for caution in the widespread adoption of recovery schools for students in recovery from SUDs. Given the lack of empirical support for these recovery schools, additional rigorous evaluation studies are needed to replicate the findings from the one study included in the review. Furthermore, additional research examining the costs of recovery schools may be needed, to help school administrators determine the potential cost-benefits associated with recovery schools.

Prenatal and concurrent cocaine, alcohol, marijuana, and tobacco effects on adolescent cognition and attention

BACKGROUND

Prenatal cocaine/polydrug exposure (PCE) may increase vulnerability to substance use disorders due to associated cognitive deficits. We examined whether neurocognitive deficits in executive functions and attention observed in PCE children persisted to adolescence when compared to non-cocaine/polydrug (NCE) children, and whether adolescent substance use (tobacco, alcohol, marijuana) was also associated with neurocognitive deficits.

METHODS

354 (180 PCE, 174 NCE) adolescents in a longitudinal study from birth were administered the Wechsler Intelligence Scales for Children - IV (WISC-IV), and the Integrated Visual and Auditory Continuous Performance Test (IVA/CPT) at age 15.5. Assessments of prenatal exposure to cocaine, alcohol, marijuana, and tobacco and measures of use at age 15.5 were taken. Confounding factors measured included lead, the caregiving environment, and violence exposure. Relationships between drug use and prenatal exposures on outcomes were assessed through multiple regression.

RESULTS

Adolescents with PCE had deficits in Perceptual Reasoning IQ and visual attention. Prenatal alcohol exposure predicted verbal and working memory IQ and visual and auditory attention deficits. Adolescent tobacco, alcohol, and marijuana use predicted attention in addition to PCE, lead and the caregiving environment.

CONCLUSION

Prenatal cocaine and alcohol exposure and adolescent use of substances are associated with neurocognitive deficits known to increase vulnerability to SUDs.

Disturbances of postural sway components in cannabis users

INTRODUCTION

A prominent effect of acute cannabis use is impaired motor coordination and driving performance. However, few studies have evaluated balance in chronic cannabis users, even though density of the CB1 receptor, which mediates the psychoactive effects of cannabis, is extremely high in brain regions critically involved in this fundamental behavior. The present study measured postural sway in regular cannabis users and used rambling and trembling analysis to quantify the integrity of central and peripheral nervous system contributions to the sway signal.

METHODS

Postural sway was measured in 42 regular cannabis users (CB group) and 36 non-cannabis users (N-CB group) by asking participants to stand as still as possible on a force platform in the presence and absence of motor and sensory challenges. Center of pressure (COP) path length was measured, and the COP signal was decomposed into rambling and trembling components. Exploratory correlational analyses were conducted between sway variables, cannabis use history, and neurocognitive function.

RESULTS

The CB group had significantly increased path length and increased trembling in the anterior-posterior (AP) direction. Exploratory correlational analyses suggested that AP rambling was significantly inversely associated with visuo-motor processing speed.

DISCUSSION

Regular cannabis use is associated with increased postural sway, and this appears to be predominantly due to the trembling component, which is believed to reflect the peripheral nervous system's contribution to the sway signal.

Common transdiagnostic cognitive deficits among people with psychiatric disorders exposed to childhood maltreatment: a meta-analysis

INTRODUCTION

Previous meta-analyses have shown a moderate negative impact of maltreatment on the neuropsychological functioning of people with or without psychiatric disorders compared to healthy groups. The objectives of the present meta-analysis were to (1) investigate the impact of maltreatment on neuropsychological functioning of people with psychiatric disorders and to (2) evaluate the moderating effect of age, at the time of the cognitive assessment, on neuropsychological functioning.

METHODS

Seventeen studies published between 1970 and July 2017 were included.

RESULTS

The results showed a negative impact of maltreatment with a small effect size (g = -0.25) on the neuropsychological performances in the group with psychiatric disorders with a history of exposure to childhood maltreatment compared to the group with psychiatric disorders without a history of exposure to childhood maltreatment. Cognitive domains that are significantly affected by maltreatment are: working memory (g = -0.56), verbal episodic memory (g = -0.39), intelligence (g = -0.27) and processing speed (g = -0.21). The impact of childhood maltreatment on the cognitive profile is greater in adults than young people.

CONCLUSIONS

Clinicians should consider these common cognitive deficits using a transdiagnostic approach in cognitive interventions.

Effects of adolescent alcohol consumption on the brain and behaviour

Per occasion, alcohol consumption is higher in adolescents than in adults in both humans and laboratory animals, with changes in the adolescent brain probably contributing to this elevated drinking. This Review examines the contributors to and consequences of the use of alcohol in adolescents. Human adolescents with a history of alcohol use differ neurally and cognitively from other adolescents; some of these differences predate the commencement of alcohol consumption and serve as potential risk factors for later alcohol use, whereas others emerge from its use. The consequences of alcohol use in human adolescents include alterations in attention, verbal learning, visuospatial processing and memory, along with altered development of grey and white matter volumes and disrupted white matter integrity. The functional consequences of adolescent alcohol use emerging from studies of rodent models of adolescence include decreased cognitive flexibility, behavioural inefficiencies and elevations in anxiety, disinhibition, impulsivity and risk-taking. Rodent studies have also showed that adolescent alcohol use can impair neurogenesis, induce neuroinflammation and epigenetic alterations, and lead to the persistence of adolescent-like neurobehavioural phenotypes into adulthood. Although only a limited number of studies have examined comparable measures in humans and laboratory animals, the available data provide evidence for notable across-species similarities in the neural consequences of adolescent alcohol exposure, providing support for further translational efforts in this context.

Antisocial Traits, Distress Tolerance, and Alcohol Problems as Predictors of Intimate Partner Violence in Men Arrested for Domestic Violence

OBJECTIVE

Men with antisocial personality disorder (ASPD) traits are at an increased risk for consuming alcohol and perpetrating intimate partner violence (IPV). However, previous research has neglected malleable mechanisms potentially responsible for the link between ASPD traits, alcohol problems, and IPV perpetration. Efforts to improve the efficacy of batterer intervention programs (BIPs) would benefit from exploration of such malleable mechanisms. The present study is the first to examine distress tolerance as one such mechanism linking men's ASPD traits to their alcohol problems and IPV perpetration.

METHODS

Using a cross-sectional sample of 331 men arrested for domestic violence and court-referred to BIPs, the present study used structural equation modeling to examine pathways from men's ASPD traits to IPV perpetration directly and indirectly through distress tolerance and alcohol problems.

RESULTS

Results supported a two-chain partial mediational model. ASPD traits were related to psychological aggression perpetration directly and indirectly via distress tolerance and alcohol problems. A second pathway emerged by which ASPD traits related to higher levels of alcohol problems, which related to psychological aggression perpetration. Controlling for psychological aggression perpetration, neither distress tolerance nor alcohol problems explained the relation between ASPD traits and physical assault perpetration.

CONCLUSION

These results support and extend existing conceptual models of IPV perpetration. Findings suggest intervention efforts for IPV should target both distress tolerance and alcohol problems.

Longitudinal pathways from unconventional personal attributes in the late 20s to cannabis use prior to sexual intercourse in the late 30s

A quarter of people living with human immunodeficiency virus (HIV) infection in the United States are women. Furthermore, African American and Hispanic/Latina women continue to be disproportionately affected by HIV, compared with women of other races/ethnicities. Cannabis use prior to intercourse may be associated with increased risky sexual behaviors which are highly related to HIV. The ultimate goal of this research is to better understand the relationships between unconventional personal attributes (e.g., risk-taking behaviors) in the late 20s, substance use (e.g., alcohol) in the mid 30s, and cannabis use prior to intercourse in the late 30s using a community sample; such an understanding may inform interventions. This study employing data from the Harlem Longitudinal Development Study includes 343 female participants (50% African Americans, 50% Puerto Ricans). Structural equation modeling indicated that unconventional personal attributes in the late 20s were associated with substance use in the mid 30s (β=0.32, p<0.001), which in turn, was associated with cannabis use prior to sexual intercourse in the late 30s (β=0.64, p<0.001). Unconventional personal attributes in the late 20s were also directly related to cannabis use prior to sexual intercourse in the late 30s (β=0.39, p<0.01). The findings of this study suggest that interventions focused on decreasing unconventional personal attributes as well as substance use may reduce sexual risk behaviors among urban African American and Puerto Rican women. Also, the implications of this study for health care providers and researchers working in HIV prevention are that these precursors may be useful as patient screening tools.

Earlier Alcohol Use Onset Predicts Poorer Neuropsychological Functioning in Young Adults

BACKGROUND

Neurodevelopment may be shaped by environmental factors such as alcohol intake. Over 20% of U.S. high school students begin drinking before age 14, and those who initiated drinking before age 14 are 4 times more likely to develop psychosocial, psychiatric, and substance use difficulties than those who began drinking after turning 20. Little is known, however, about how the age of alcohol use onset influences brain development.

METHODS

This study prospectively examined the effects of alcohol use onset age on neurocognitive functioning in healthy adolescent drinkers (N = 215). Youth were administered a neuropsychological battery before substance use initiation (M = 13.6 years, SD = 0.8) and on average 6.8 years later (M = 20.2 years, SD = 1.5). Hierarchical linear regressions examined if earlier ages of onset for first and regular (i.e., weekly) alcohol use adversely influenced neurocognition, above and beyond baseline neurocognition, substance use severity, and familial and social environment factors.

RESULTS

As hypothesized, an earlier age of first drinking onset (AFDO) predicted poorer performance in the domains of psychomotor speed and visual attention (ps<0.05, N = 215) and an earlier age of weekly drinking onset (AWDO) predicted poorer performances on tests of cognitive inhibition and working memory, controlling for baseline neuropsychological performance, drinking duration, and past-year marijuana use (ps<0.05, N = 127). No relationship between AFDO and AWDO was found with verbal learning and memory and visuospatial ability.

CONCLUSIONS

This is the first study to assess the association between age of adolescent drinking onset and neurocognitive performance using a comprehensive test battery. This study suggests that early onset of drinking increases risk for alcohol-related neurocognitive vulnerabilities and that initiation of any or weekly alcohol use at younger ages appears to be a risk factor for poorer subsequent neuropsychological functioning. Findings have important implications for public policies related to the legal drinking age and prevention programming. Further studies are needed to replicate these preliminary findings and better understand mediating processes and moderating conditions.

High-intensity and simultaneous alcohol and marijuana use among high school seniors in the United States

BACKGROUND

Simultaneous alcohol and marijuana (SAM) use poses threats to health, particularly among adolescents. These risks would be exacerbated to the extent that high-intensity drinking (e.g., 10+ drinks in a row) and marijuana use (e.g., 1+ joints per day) are associated with a higher likelihood of SAM use. The current study examines the extent to which the intensity of alcohol use and of marijuana use are associated with adolescent SAM use prevalence, and whether associations remain after controlling for key covariates known to associate with both alcohol and marijuana use; it identifies alcohol and marijuana use intensity levels associated with the highest risk of adolescent SAM use.

METHODS

Data come from nationally representative samples of US 12th graders who participated in the Monitoring the Future study from 2005 to 2014 (N = 24,203 respondents; 48.4% boys, 51.6% girls).

RESULTS

SAM use during the past year was reported by 20% of 12th graders overall. SAM use prevalence was strongly and positively associated with alcohol and marijuana use intensity even after controlling for covariates. High school seniors at highest risk for engaging in SAM use were those who reported 10+ drinks and those smoking at least 1 joint/day. Approximately 60% of those who had 10-14 or 15+ drinks in a row during the past 2 weeks and 76%-80% of those who had 1 or 2+ joints per day on average during the past 30 days reported SAM use.

CONCLUSIONS

Results suggest that high school seniors who consume high quantities of alcohol and marijuana are very likely to consume these substances so that their effects overlap.

Impact of Perceived Risk and Friend Influence on Alcohol and Marijuana Use Among Students

We performed a secondary analysis of Adolescent Health Risk Behavior Survey data ( N = 937), examining associations between lifetime alcohol and marijuana use with intrapersonal (i.e., risk perceptions) and interpersonal (e.g., peer approval and behavior) factors. Multinomial and binary logistic regression analyses contend students reporting lifetime alcohol use-compared to students who had never used alcohol or marijuana-perceived lower alcohol risk ( p < .001), higher friend drinking approval ( p < .001), and greater friend drinking ( p = .003). Using both alcohol and marijuana in one's life was associated with being in public schools ( p = .010), higher grade levels ( p = .001), lower perceived alcohol ( p = .011) and marijuana use risk ( p = .003), higher friend approval of alcohol ( p < .001) and marijuana use ( p < .001), and believed more friends used alcohol ( p < .001). Compared to lifetime alcohol only, perceived friend academic performance decreased the risk of lifetime alcohol and marijuana use ( p = .043). Findings are beneficial to school nurses with students experiencing effects associated with substance use.

Early Initiation of Amphetamine-Type Stimulants (ATS) Use Associated with Lowered Cognitive Performance among Individuals with Co-Occurring Opioid and ATS Use Disorders in Malaysia

Amphetamine-type stimulants (ATS) use is increasingly prevalent in Malaysia, including among individuals who also use opioids. We evaluated cognitive functioning profiles among individuals with co-occurring opioid and ATS dependence and their lifetime patterns of drug use. Participants (N = 50) enrolling in a clinical trial of buprenorphine/naloxone treatment with or without atomoxetine completed the Raven's Standard Progressive Matrices, Rey-Osterrieth Complex Figure Test, Digit Span, Trail Making and Symbol Digit Substitution tasks. Multidimensional scaling and a K-means cluster analyses were conducted to classify participants into lower versus higher cognitive performance groups. Subsequently, analyses of variance procedures were conducted to evaluate between group differences on drug use history and demographics. Two clusters of individuals with distinct profiles of cognitive performance were identified. The age of ATS use initiation, controlling for the overall duration of drug use, was significantly earlier in the lower than in the higher cognitive performance cluster: 20.9 (95% CI: 18.0-23.8) versus 25.2 (95% CI: 22.4-28.0, p = 0.038). While adverse effects of ATS use on cognitive functioning can be particularly pronounced with younger age, potentially related to greater vulnerability of the developing brain to stimulant and/or neurotoxic effects of these drugs, the current study findings cannot preclude lowered cognitive performance before initiation of ATS use.

Empathy, and its relationship with cognitive and emotional functions in alcohol dependency

BACKGROUND

Empathy can be defined as the ability to understand the other's thoughts and feelings. It contains both cognitive and emotional components.

AIMS

The aim of this study was to investigate the empathy ability of patients with alcohol dependency in association with cognitive and emotional functions, after acute detoxification and during long-term abstinence.

METHODS

Thirty-three alcohol dependent inpatients that completed a detoxification process and stayed abstinent throughout the study, and 33 healthy comparison subjects that matched the patients for age, gender, and education level were included in the study. All the participants were administered the Facial Emotion Identification Test (FEIT), Facial Emotion Discrimination Test (FEDT), Trail Making Test (TMT), Digit Span Test (DST), Auditory Consonant Trigram Test (ACT), and Empathy Quotient Scale (EQS). All the tests were repeated after 3 months of abstinence.

RESULTS

At the first evaluation conducted after detoxification, patients performed significantly worse than healthy comparisons in almost all tests. At the second evaluation, which was conducted after 3 months of abstinence, the patients improved significantly in all measures, and no significant differences were detected between the patient and comparison groups. There were significant correlations between the test scores and EQS score.

CONCLUSIONS

Alcohol dependency has deleterious effects on empathy ability, and cognitive and emotional functions. Those impairments can improve with abstinence. Empathy ability has strong relationships with cognitive and emotional functions.

Cannabis and alcohol use, and the developing brain

Sex hormones and white (and grey) matter in the limbic system, cortex and other brain regions undergo changes during adolescence. Some of these changes include ongoing white matter myelination and sexually dimorphic features in grey and white matter. Adolescence is also a period of vulnerability when many are first exposed to alcohol and cannabis, which appear to influence the developing brain. Neuropsychological studies have provided considerable understanding of the effects of alcohol and cannabis on the brain. Advances in neuroimaging have allowed examination of neuroanatomic changes, metabolic and neurotransmitter activity, and neuronal activation during adolescent brain development and substance use. In this review, we examine major differences in brain development between users and non-users, and recent findings on the influence of cannabis and alcohol on the adolescent brain. We also discuss associations that appear to resolve following short-term abstinence, and attentional deficits that appear to persist. These findings can be useful in guiding earlier educational interventions for adolescents, and clarifying the neural sequelae of early alcohol and cannabis use to the general public.

Integrated oral, mental and sexual health management for adolescents: a call for professional collaboration

BACKGROUND

Globally, young people account for 15.5% of the total global disability-adjusted life-years burden for all age groups. They face mental health, nutritional problems, accidental and intentional injuries, sexual and reproductive health problems, and substance abuse. These health challenges have effects on their oral health. This paper discusses the oral health problems adolescents face and suggests approaches for providing integrated oral and general health care for adolescents.

DISCUSSION

Oral health issues linked with adolescent health concerns include: malocclusion and esthetic concerns linked with mental health status; oral and maxillofacial injuries linked with accidental and intentional injuries; oral manifestations of sexually transmitted infections; oral leukoplakia and oral cancers linked with alcohol, tobacco and psychoactive substance abuse; and oral manifestations of anemia resulting from nutritional problems. Training oral health care providers on adolescent health and care could promote prompt diagnosis, management and prevention of complications associated with major health challenges affecting adolescents.

CONCLUSION

Adolescent oral health care needs focused attention: as a possible route for early diagnosis and management of general health problems and for promoting adolescent oral health care. Oral health care should be integrated into adolescent friendly services and oral health care providers should learn how to handle adolescents' health needs.

The Mediating Influence of Treatment Participation Rate on Post-Treatment Employment

This study explored treatment participation rate as a mediator between individuals’ baseline alcohol use, drug use, and psychiatric issue levels and post-treatment employment status. The study sample included 106 unemployed or underemployed individuals with substance use disorders who were participants in an intensive drug abuse treatment program. Structural equation modeling was applied to examine relationships between study variables. The results showed that (a) the direct effect of individuals’ baseline alcohol use, drug use, and psychiatric issue severities reduced treatment participation rate; (b) the direct effect of treatment participation rate ameliorated post-treatment employment status; and (c) the indirect effect of individuals’ baseline alcohol use, drug use, and psychiatric issue severities on post-treatment employment status was mediated by treatment participation rate, which reduced the negative influence of baseline issue severity on employment. This significant mediating effect has both practical and theoretical importance in that it indicates the need for increased focus on treatment participation in practice and future research.

Addictions Neuroclinical Assessment: A Neuroscience-Based Framework for Addictive Disorders

This article proposes a heuristic framework for the Addictions Neuroclinical Assessment that incorporates key functional domains derived from the neurocircuitry of addiction. We review how addictive disorders (ADs) are presently diagnosed and the need for new neuroclinical measures to differentiate patients who meet clinical criteria for addiction to the same agent while differing in etiology, prognosis, and treatment response. The need for a better understanding of the mechanisms provoking and maintaining addiction, as evidenced by the limitations of current treatments and within-diagnosis clinical heterogeneity, is articulated. In addition, recent changes in the nosology of ADs, challenges to current classification systems, and prior attempts to subtype individuals with ADs are described. Complementary initiatives, including the Research Domain Criteria project, that have established frameworks for the neuroscience of psychiatric disorders are discussed. Three domains-executive function, incentive salience, and negative emotionality-tied to different phases in the cycle of addiction form the core functional elements of ADs. Measurement of these domains in epidemiologic, genetic, clinical, and treatment studies will provide the underpinnings for an understanding of cross-population and temporal variation in addictions, shared mechanisms in addictive disorders, impact of changing environmental influences, and gene identification. Finally, we show that it is practical to implement such a deep neuroclinical assessment using a combination of neuroimaging and performance measures. Neuroclinical assessment is key to reconceptualizing the nosology of ADs on the basis of process and etiology, an advance that can lead to improved prevention and treatment.

Effects of Emerging Alcohol and Marijuana Use Behaviors on Adolescents' Neuropsychological Functioning Over Four Years

OBJECTIVE

Adolescence is a period of neuromaturation concomitant with increased substance involvement. Most substance use studies of adolescents have focused on categorical classifications (e.g., dependent vs. nondependent), but little is known about the influence of specific substance use behaviors on cognitive functioning in youth.

METHOD

This study prospectively evaluated the quantitative effects of different substance use behaviors on neuropsychological functioning. A cognitive test battery was administered at baseline (ages 12-14 years), before substance use initiation, and at follow-up (M = 4.0 years, SD = 2.0) to evaluate changes in verbal memory, visuospatial ability, psychomotor speed, processing speed, and working memory. Robust regressions examined substance use behaviors as predictors of neuropsychological functioning (N = 234).

RESULTS

Several substance use behaviors predicted follow-up neuropsychological functioning above and beyond effects of baseline performance on the same measure (ps < .05). Specifically, more alcohol use days predicted worse verbal memory (β = -.15) and visuospatial ability (β = -.19). More postdrinking effects (β = -.15) and greater drug use (β = -.11) predicted worse psychomotor speed. Processing speed was not predicted by substance involvement (ps > .05). Unexpectedly, more alcohol use predicted better working memory performance (β = .12).

CONCLUSIONS

The frequency and intensity of adolescent alcohol use may be more intricately linked to neuropsychological outcomes than previously considered. The low prevalence of substance use disorder in the sample suggests that subdiagnostic users may still experience adverse effects to verbal memory, visuospatial functioning, and psychomotor speed after initiating intense or frequent alcohol use.

Promoting "Healthy Futures" to Reduce Risk Behaviors in Urban Youth: A Randomized Controlled Trial

There is increasing evidence of the interconnection between educational and health outcomes. Unfortunately wide disparities exist by both socioeconomic status and race/ethnicity in educational and vocational success. This study sought to promote urban youths' career readiness as a way to reduce involvement in risk behaviors. Two hundred primarily African-American youth (ages 14-21) were recruited from a pediatric primary care clinic. Youth randomized to the intervention received three motivational interviewing sessions focused around expectations and planning for the future. Baseline and 6-month follow-up assessments included measures of career readiness and risk behavior involvement (i.e., physical fighting, alcohol and marijuana use). At 6-months, youth randomized to the intervention condition showed increased confidence in their ability to perform the behaviors needed to reach their college/career goals. Additionally, youth randomized to the intervention arm showed decreased fighting behavior (adjusted rate ratio: .27) and marijuana use (adjusted rate ratio: .61). Assisting urban youth in thinking and planning about their future holds promise as a way to reduce their involvement in risk behaviors. This study also demonstrated that motivational interviewing could be used to promote positive behaviors (i.e., career readiness).

Effects of marijuana use on prefrontal and parietal volumes and cognition in emerging adults

RATIONALE

Chronic marijuana (MJ) use among adolescents has been associated with structural and functional abnormalities, particularly in developing regions responsible for higher order cognition.

OBJECTIVES

This study investigated prefrontal (PFC) and parietal volumes and executive function in emerging adult MJ users and explored potential gender differences.

METHODS

Participants (ages 18-25) were 27 MJ users and 32 controls without neurologic or psychiatric disorders or heavy other drug use. A series of multiple regressions examined whether group status, past year MJ use, and their interactions with gender predicted ROI volumes. Post hoc analyses consisted of brain-behavior correlations between volumes and cognitive variables and Fisher's z tests to assess group differences.

RESULTS

MJ users demonstrated significantly smaller medial orbitofrontal (mOFC; p = 0.004, FDR p = 0.024) and inferior parietal volumes (p = 0.04, FDR p = 0.12); follow-up regressions found that increased past year MJ use did not significantly dose-dependently predict smaller mOFC volume in a sub-sample of individuals with at least one past year MJ use. There were no significant gender interactions. There was a significant brain-behavior difference by group, such that smaller mOFC volumes were associated with poorer complex attention for MJ users (p < 0.05).

CONCLUSIONS

Smaller mOFC volumes among MJ users suggest disruption of typical neurodevelopmental processes associated with regular MJ use for both genders. These results highlight the need for longitudinal, multi-modal imaging studies providing clearer information on timing of neurodevelopmental processes and neurocognitive impacts of youth MJ initiation.

Neuropsychological Performance in Polyconsumer Men Under Treatment. Influence of Age of Onset of Substance Use

Neurocognition is a key factor in the development and maintenance of Substance Use Disorders (SUD). However, there are still several aspects that need to be studied in this area. In this study, we elucidate the influence of age of onset of substance use (OSU) on the clinical course and neuropsychological performance of substance use disorder (SUD) patients, as well as to explore the influence of years of education, duration of drug use and premorbid intelligence quotient (IQ) on the cognitive results obtained. An exhaustive neuropsychological battery was used to assess different cognitive domains in 80 male polyconsumers, 41 with earlier OSU (16 years or before: OSU ≤ 16) and 39 with later OSU (17 years or later: OSU ≥ 17). The patients were under treatment with at least 4 months of abstinence confirmed by urinalysis. The OSU ≤ 16 group presented a worse clinical state, as well as a lower premorbid IQ and worse performance in processing speed, visual perception and planning skills. The duration of drug use may account for the differences in planning and processing speed. In this work we discuss the premorbid or acquired nature of the cognitive deficits found.

Cortical thickness and neurocognition in adolescent marijuana and alcohol users following 28 days of monitored abstinence

OBJECTIVE

Adolescent marijuana use continues to increase in prevalence as harm perception declines. Better understanding of marijuana's impact on neurodevelopment is crucial. This prospective study aimed to investigate cortical thickness and neurocognitive performance before and after 28 days of monitored abstinence in adolescent marijuana and alcohol users.

METHOD

Subjects (N = 54; >70% male) were adolescent marijuana users (ages 15-18 years) with regular alcohol use (MJ + ALC; n = 24) and non-using controls (CON; n = 30) who were compared before and after 4 weeks of sequential urine toxicology to confirm abstinence. Participants underwent magnetic resonance imaging, neuropsychological assessment, and substance use assessment at both time points. Repeated-measures analysis of covariance was used to look at the main effects of group, time, and Group × Time interactions on cortical thickness and neurocognitive functioning. Bivariate correlations estimated associations between cortical thickness, substance use severity, and cognitive performance.

RESULTS

Marijuana users showed thicker cortices than controls in the left entorhinal cortex (ps < .03) before and after monitored abstinence, after adjusting for lifetime alcohol use. More lifetime marijuana use was linked to thinner cortices in temporal and frontal regions, whereas more lifetime alcohol use and heavy episodic drinking episodes was linked to thicker cortices in all four lobes (ps < .05). Age of onset of regular marijuana use was positively related to cortical thickness (ps < .03).

CONCLUSIONS

Adolescent alcohol and marijuana use may be linked to altered longer-term neurodevelopmental trajectories and compromised neural health. Cortical thickness alterations and dose-dependent associations with thickness estimates were observed both before and after monitored abstinence and suggest neural differences continue to persist 28 days after cessation of marijuana use. Neural recovery may be identified with longer follow-up periods; however, observed changes related to use severity could have implications for future psychosocial outcomes.