Neuropsychological and neurophysiological predictors and consequences of cannabis and illicit substance use during neurodevelopment: a systematic review of longitudinal studies

Neuroscience-informed classification of prevention interventions in substance use disorders: An RDoC-based approach

Neuroscience has contributed to uncover the mechanisms underpinning substance use disorders (SUD). The next frontier is to leverage these mechanisms as active targets to create more effective interventions for SUD treatment and prevention. Recent large-scale cohort studies from early childhood are generating multiple levels of neuroscience-based information with the potential to inform the development and refinement of future preventive strategies. However, there are still no available well-recognized frameworks to guide the integration of these multi-level datasets into prevention interventions. The Research Domain Criteria (RDoC) provides a neuroscience-based multi-system framework that is well suited to facilitate translation of neurobiological mechanisms into behavioral domains amenable to preventative interventions. We propose a novel RDoC-based framework for prevention science and adapted the framework for the existing preventive interventions. From a systematic review of randomized controlled trials using a person-centered drug/alcohol preventive approach for adolescents, we identified 22 unique preventive interventions. By teasing apart these 22 interventions into the RDoC domains, we proposed distinct neurocognitive trajectories which have been recognized as precursors or risk factors for SUDs, to be targeted, engaged and modified for effective addiction prevention.

Changes in Cannabis Use From 2014 to 2019 Among Young Adults in Washington State

INTRODUCTION

Understanding changes in cannabis use in the legalized nonmedical cannabis context is critical. Washington State, one the earliest states to implement legalization, presents a unique opportunity to examine how cannabis use and its consequences changed after the implementation of legalization for adults. With a focus on Washington State young adults, this study conducted in 2022-2023 examined changes in (1) cannabis use by sex and age, (2) preferred mode of use, and (3) cannabis use disorder symptoms.

METHODS

Using repeated cross-sectional data on young adults aged 18-25 years in Washington State from 2014 (premarket opening) to 2019 (N=12,945), logistic regression models assessed trends over time in the prevalence of any and frequent (20+ days) past-month cannabis use. Among individuals reporting use, multinomial logistic regressions estimated trends over time in the preferred mode of use and negative binomial regressions examined trends in the count of cannabis use disorder symptoms.

RESULTS

From 2014 to 2019, the prevalence of cannabis use converged by sex, with females being equally likely as males to report both any and frequent use by 2019. Among young adults reporting past-month use, smoking as the preferred mode of use decreased relative to other modes. Number of cannabis use disorder symptoms reported increased, which was not accounted for by changes in preferred mode of use.

CONCLUSIONS

During the 5-year period following the implementation of legalization, patterns of young adult cannabis use shifted, including particularly sharp increases among females and increases in cannabis use disorder symptoms. Future studies should investigate underlying causes for these important changes.

Caffeinated Soda Intake in Children Is Associated with Neurobehavioral Risk Factors for Substance Misuse

BACKGROUND AND OBJECTIVES

Use of psychotropic substances in childhood has been associated with both impulsivity and other manifestations of poor executive function as well as escalation over time to use of progressively stronger substances. However, how this relationship may start in earlier childhood has not been well explored. Here, we investigated the neurobehavioral correlates of daily caffeinated soda consumption in preadolescent children and examined whether caffeinated soda intake is associated with a higher risk of subsequent alcohol initiation.

METHODS

Using Adolescent Brain Cognitive Development study data (N = 2,092), we first investigated cross-sectional relationships between frequent caffeinated soda intake and well-known risk factors of substance misuse: impaired working memory, high impulsivity, and aberrant reward processing. We then examined whether caffeinated soda intake at baseline predicts more alcohol sipping at 12 months follow-up using a machine learning algorithm.

RESULTS

Daily consumption of caffeinated soda was cross-sectionally associated with neurobehavioral risk factors for substance misuse such as higher impulsivity scores and lower working memory performance. Furthermore, caffeinated soda intake predicted a 2.04 times greater likelihood of alcohol sipping after 12 months, even after controlling for rates of baseline alcohol sipping rates.

CONCLUSIONS

These findings suggest that previous linkages between caffeine and substance use in adolescence also extend to younger initiation, and may stem from core neurocognitive features thought conducive to substance initiation.

Clinical Characteristics, Support System, and Personality Differences of Cannabis and Stimulant Users in South Korea

OBJECTIVE

To compare the clinical characteristics, support system, and personality traits of cannabis and stimulant users in South Korea.

METHODS

This study was based on electronic medical records. Among a total of 152 subjects who suspected of drug use and who underwent six types of urine-based drug screening tests at the National Center for Mental Health, 104 people who underwent both an interview with a psychiatrist and a psychological test were selected and classified according to the type of substance used. Psychological and personality characteristics were examined through the National Center for Mental Health psychological test battery for addiction. The differences in characteristics between cannabis (n=60) and stimulant (n=18) users were analyzed by an independent t-test for parametric data and chi-square test or Fisher's exact test for nonparametric data, and analysis of covariance for psychological tests.

RESULTS

The average age of cannabis users was lower than that of stimulant users and they were more often single. Substance cravings were higher in stimulant users, who more often had a psychiatric history than cannabis users. Moreover, stimulant users had higher clinical scale scores for depression and anxiety. Among the Minnesota Multiphasic Personality Inventory-II clinical scale scores, there was a significant difference in social introversion scores between groups.

CONCLUSION

We found differences in demographic, psychological, and personality characteristics between cannabis and stimulant users in South Korea. Considering the recent increase in illegal drug use in South Korea, further follow-up and policy research on drug users are needed.

Associations between School-Behavior-Health Difficulties and Subsequent Injuries among Younger Adolescents: A Population-based Study

Objective: School-behavior-health difficulties (SBHDs) may alter physical/mental capabilities and consequently increase injury risk during daily activities. This study assessed the associations of potential SBHDs and their cumulative number (SBHDcn) with various injury types among younger adolescents. Methods: The study population included 1,559 middle-school adolescents in France (10-18 years, 98% under 16,778 boys and 781 girls). They completed a questionnaire at school-year end collecting socioeconomic features (nationality, family structure, parents' education/occupation/income), school/out-of-school injuries during the school-year (dependent variables), and SBHDs starting before the school-year (low academic performance, alcohol/tobacco/cannabis/other-illicit-drugs use, physical/verbal violence, sexual abuse, perpetrated violence, poor social support, poor general health status, sleep difficulty, depressive symptoms, and suicide attempt). Data were analyzed using logistic regression models and Kaplan-Meier estimates. Results: Injuries were frequent during school-physical/sports-training (10.9%), other-school-training (4.7%), school-free-time (7.4%), out-of-school-sports-activity (16.5%), and traffic (2.2%). Single injury (one injury all injury types combined) and ≥2 injury types affected 23.3 and 7.9% of subjects, respectively. The proportion of adolescents without SBHDs decreased with age more quickly among those with each injury type than among those without injury. Various SBHDs were associated with most injury types, single injury, and ≥2 injury types (sex-age-adjusted odds/relative-risk ratios reaching 11, p < .001). A dose-effect association was found between SBHDcn 1-2/3-5/≥6 and both single injury and ≥2 injury types (sex-age adjusted relative risk ratios reaching 12.66, p < .001, vs. SBHDcn = 0). Socioeconomic features had a moderate confounding role in these associations. Conclusions: SBHDs strongly predict injuries among adolescents. Our findings may inform healthcare providers about their prominent role in detecting/reducing SBHDs and injuries.

Cognitive Alterations in Addictive Disorders: A Translational Approach

The cognitive decline in people with substance use disorders is well known and can be found during both the dependence and drug abstinence phases. At the clinical level, cognitive decline impairs the response to addiction treatment and increases dropout rates. It can be irreversible, even after the end of drug abuse consumption. Improving our understanding of the molecular and cellular alterations associated with cognitive decline could be essential to developing specific therapeutic strategies for its treatment. Developing animal models to simulate drug abuse-induced learning and memory alterations is critical to continue exploring this clinical situation. The main aim of this review is to summarize the most recent evidence on cognitive impairment and the associated biological markers in patients addicted to some of the most consumed drugs of abuse and in animal models simulating this clinical situation. The available information suggests the need to develop more studies to further explore the molecular alterations associated with cognitive impairment, with the ultimate goal of developing new potential therapeutic strategies.

Predictors of illicit substance abuse/dependence during young adulthood: A machine learning approach

Prior studies have found an especially high prevalence of illicit substance use among adolescents and young adults in Brazil. The current study aimed to employ machine learning techniques to identify predictors of illicit substance abuse/dependence among a large community sample of young adults followed for 5 years. This prospective, population-based cohort study included a sample of young adults between the ages of 18-24 years from Pelotas, Brazil at baseline (T1). The Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) was used to assess illicit substance abuse/dependence. A clinical interview was conducted to collect data on sociodemographic characteristics and psychopathology. Elastic net was used to generate a regularized linear model for the machine learning component of this study, which followed standard machine learning protocols. A total of 1560 young adults were assessed at T1, while 1244 were reassessed at the 5-year follow-up period (T2). The strongest predictors of illicit substance abuse/dependence at baseline (AUC of 0.83) were alcohol abuse/dependence, tobacco abuse/dependence, being in a current major depressive episode, history of a lifetime manic episode, current suicide risk, and male sex. The strongest predictors for illicit substance abuse/dependence at the 5-year follow-up (AUC: 0.79) were tobacco abuse/dependence at T1, history of a lifetime manic episode at T1, male sex, alcohol abuse/dependence at T1, and current suicide risk at T1. Our findings indicate that machine learning techniques hold the potential to predict illicit substance abuse/dependence among young adults using sociodemographic/clinical characteristics, with relatively high accuracy.

eHealth interventions targeting poor diet, alcohol use, tobacco smoking and vaping among disadvantaged youth: A systematic review protocol (Preprint)

Background

Chronic disease burden is higher among disadvantaged populations. Preventing lifestyle risk behaviors such as poor diet, alcohol use, tobacco smoking, and vaping in adolescence is critical for reducing the risk of chronic disease and related harms in adolescence and adulthood. Although eHealth interventions are a promising prevention approach among the general population, it is unclear whether they adequately serve adolescents from disadvantaged backgrounds such as those living in geographically remote or lower socioeconomic areas.

Objective

This is the first systematic review to identify, evaluate, and synthesize evidence for the effectiveness of eHealth interventions targeting adolescents living in geographically remote or lower socioeconomic areas in preventing poor diet, alcohol use, tobacco smoking, and vaping.

Methods

A systematic search will be conducted in 7 electronic databases: the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PROSPERO, MEDLINE (Ovid), Embase (Ovid), Scopus, and PsycInfo (Ovid). The search will be limited to eHealth-based experimental studies (ie, randomized controlled trials and quasi-experimental studies) targeting diet, alcohol use, tobacco smoking, and vaping among adolescents (aged 10-19 years). Eligible studies will be those reporting on at least one marker of socioeconomic status (eg, social class, household income, parental occupation status, parental education, and family affluence) or geographical remoteness (eg, living in rural, regional, and remote areas, or living outside major metropolitan centers). One reviewer will screen all studies for eligibility, of which 25% will be double-screened. Data will be extracted and summarized in a narrative synthesis. Risk of bias will be assessed using the Cochrane Revised Risk of Bias Tool.

Results

As of December 2021, the title and abstract screening of 3216 articles was completed, and the full-text review was underway. The systematic review is expected to be completed in 2022.

Conclusions

This systematic review will provide an in-depth understanding of effective eHealth interventions targeting poor diet, alcohol use, tobacco smoking, and vaping among adolescents living in geographically remote or lower socioeconomic areas and the factors that contribute to their effectiveness. This in turn will provide critical knowledge to improve future interventions delivered to these populations.

Trial Registration

PROSPERO CRD42021294119; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=294119

International Registered Report Identifier (IRRID)

PRR1-10.2196/35408

Alcohol and Cannabis Use and the Developing Brain

PURPOSE

Alcohol and cannabis are the most commonly used substances during adolescence and are typically initiated during this sensitive neurodevelopmental period. The aim of this review is to provide a comprehensive overview of the most recent literature focused on understanding how these substances affect the developing brain.

SEARCH METHODS

Articles included in this review were identified by entering 30 search terms focused on substance use, adolescence, and neurodevelopment into MEDLINE, Embase, PsycINFO, ProQuest Central, and Web of Science. Studies were eligible for inclusion if they longitudinally examined the effect of adolescent alcohol and/or cannabis use on structural or functional outcomes in 50 or more participants.

SEARCH RESULTS

More than 700 articles were captured by the search, and 43 longitudinal studies met inclusion criteria, including 18 studies focused on alcohol use, 13 on cannabis use, and 12 on alcohol and cannabis co-use.

DISCUSSION AND CONCLUSIONS

Existing studies suggest heavy alcohol and cannabis use during adolescence are related to small to moderate disruptions in brain structure and function, as well as neurocognitive impairment. The effects of alcohol use include widespread decreases in gray matter volume and cortical thickness across time; slowed white matter growth and poorer integrity; disrupted network efficiency; and poorer impulse and attentional control, learning, memory, visuospatial processing, and psychomotor speed. The severity of some effects is dependent on dose. Heavy to very heavy cannabis use is associated with decreased subcortical volume and increased frontoparietal cortical thickness, disrupted functional development, and decreased executive functioning and IQ compared to non-using controls. Overall, co-use findings suggest more pronounced effects related to alcohol use than to cannabis use. Several limitations exist in the literature. Sample sizes are relatively small and demographically homogenous, with significant heterogeneity in substance use patterns and methodologies across studies. More research is needed to clarify how substance dosing and interactions between substances, as well as sociodemographic and environmental factors, affect outcomes. Larger longitudinal studies, already underway, will help clarify the relationship between brain development and substance use.

Neuroscience literacy and substance use prevention: How well do young people understand their brain?

ISSUE

Reducing substance use harm in young people is a major public health priority, however, health promotion messages often struggle to achieve meaningful engagement. Neuroscience-based teachings may provide an innovative new way to engage young people in credible harm minimisation health promotion. This study aims to evaluate the acceptability and credibility of a series of neuroscience-based drug education animations and investigate neuroscience literacy in young people.

METHODS

Three animations were developed around the impact of alcohol, MDMA and cannabis use on the growing brain, labelled the 'Respect Your Brain' video series. Sixty young people (mean age 21.9 years; 48% female) viewed the animations and completed a 20-minute web-based, self-report survey to provide feedback on the animations and a 19-item neuroscience literacy survey, assessing knowledge and attitudes towards the brain.

RESULTS

The Alcohol, Cannabis and MDMA videos were rated as good or very good by the majority of participants (82%, 89% and 85%, respectively) and all participants wanted to see more 'Respect your Brain' videos. On average the Alcohol, Cannabis and MDMA videos were rated as containing the right level of detail and being interesting, relevant and engaging by the majority of participants (80%, 81% and 83%, respectively). Participants scored an average of 74% in the neuroscience literacy questionnaire, demonstrating some knowledge of brain functioning and positive attitudes towards the brain.

CONCLUSION

This study provides evidence that age-appropriate, neuroscience-based resources on alcohol, Cannabis and MDMA are engaging and relevant to young people and offer a potential new avenue to reduce alcohol and other drug related harm and promote healthy lifestyle choices in young people.