Long-term consequences of adolescent cannabis use: Examining intermediary processes

Persistent increased severity of cannabis use disorder symptoms in adolescents compared to adults: a one-year longitudinal study

Adolescence is a developmental period characterised by increased vulnerability to cannabis use disorder (CUD). However, previous investigations of this vulnerability have relied on cross-sectional comparisons and lack a detailed assessment of cannabis quantity, a potentially important confounding factor. Here, we aimed to investigate the one-year course of CUD in adolescents compared to adults who currently use cannabis, adjusting for a comprehensive measure of cannabis quantity. Data are from a one-year observational longitudinal study (CannTeen) of adolescents and adults who currently used cannabis regularly with five waves of assessment at 3-monthly intervals, based in London, UK. Participants were n = 70 adults (26-29, 45.7% female), who did not regularly use cannabis when they were under age 18, and n = 76 adolescents (16-17, 50.0% female). The exposure was adolescent (compared to adult) frequent cannabis use. The primary outcome was CUD symptoms measured using the cannabis use disorder identification test revised (CUDIT-R) at five time points. Models were adjusted for cannabis quantity using mean weekly standard THC units (one unit = 5 mg THC). Other covariates included gender, and whether each session occurred before or during the COVID-19 pandemic. In models adjusted for pre-registered covariates, adolescents scored 3.7 points higher on the CUDIT-R compared to the adult group across the 5 assessment waves (3.66 95% CIs 1.99, 5.34). There was also evidence of a linear reduction in symptoms over time in both groups (-0.47, 95%CIs -0.67, -0.27). Adolescents had persistently increased CUD symptoms compared to adults across the 12-month period. This association was robust after adjusting for the quantity of cannabis consumed and other covariates.

Ecological validity of common behavioral decision making tasks: evidence across two samples

BACKGROUND

Clinicians and scholars routinely use behavioral decision tasks to assess real-world decision making capabilities. However, many common behavioral decision making tasks lack data on the extent to which they predict real-world risky behaviors. Across two pre-registered studies, and two timepoints, we assessed decision making abilities using common behavioral tasks and predicted participants' real-world risky decision making from task performance.

METHOD

In Study 1, 918 Mechanical Turk (MTurk) workers completed three decision making tasks in addition to assessments of real-world risk behavior: preventive health behaviors, COVID-19 vaccination status, and virtual social distancing task performance. In Study 2, 221 college student participants completed the Study 1 tasks plus additional assessments of decision making and real world risk and protective behaviors.

RESULTS

Across both studies, the selected behavioral decision tasks rarely predicted real world behavior and, when they did, the relationship was weak at best.

CONCLUSIONS

These data suggest that these behavioral decision making tasks may not be good predictors of real world risky behavior at present, with some evidence that the specificity of the behavior being assessed matters (i.e. the closer the task was to the specific behavior being predicted), calling for additional ecological validity research, with a greater variety of tasks in the future.

Individual and Community level Developmental Adversities: Associations with Marijuana and Alcohol Use in Late-Adolescents and Young Adults

Exposure to community and individual level stressors during adolescence has been reported to be associated with increased substance use. However, it remains unclear what the relative contribution of different community- and individual-level factors play when alcohol and marijuana use become more prevalent during late adolescence. The present study uses a large longitudinal sample of adolescents (Wave 1: N = 2017; 55% Female; 54.5% White, 22.3% Black, 8% Hispanic, 15% other) to evaluate the association and potential interactions between community- and individual-level factors and substance use from adolescence to young adulthood (Wave 1 to Wave 3 Age Mean [SD]: 16.7 [1.1], 18.3 [1.2], 19.3 [1.2]). Across three waves of data, multilevel modeling (MLM) is used to evaluate the association between community affluence and disadvantage, individual household socioeconomic status (SES, measured as parental level of education and self-reported public assistance) and self-reported childhood maltreatment with self-reported 12-month alcohol and 12-month marijuana use occasions. Sample-selection weights and attrition-adjusted weights are accounted for in the models to evaluate the robustness of the estimated effects. Across the MLMs, there is a significant positive association between community affluence and parental education with self-reported alcohol use but not self-reported marijuana use. In post hoc analyses, higher neighborhood affluence in older adolescents is associated with higher alcohol use and lower use in younger adolescents; the opposite association is found for neighborhood disadvantage. Consistent with past literature, there is a significant positive association between self-reported childhood maltreatment and self-reported 12-month alcohol and 12-month marijuana use. Results are largely consistent across weighted and unweighted analyses, however, in weighted analyses there is a significant negative association between community disadvantage and self-reported 12-month alcohol use. This study demonstrates a nuanced relationship between community- and individual-level factors and substance use during the transitional window of adolescence which should be considered when contextualizing and interpreting normative substance use during adolescence.

"I Like the Vibes it Gives": Adolescent Perspectives on Cannabis Billboards and Print Advertising in Nevada

An influx of laws permitting recreational cannabis sales in the US has allowed for increased advertising. The purpose of this study was to describe how adolescents perceive outdoor and print cannabis advertising and to identify aspects of advertising that are appealing or eye-catching, focusing on five themes: price promotion, sex appeal, wellness, party, and text-only. We recruited adolescents ages 11-17 to participate in seven focus groups (44 participants) from 2019 to 2020. Participants viewed cannabis advertisements and responses were summarized using deductive thematic analysis. The party-themed advertisements were the most salient to participants, who desired to emulate the behaviors shown. Participants favored ads featuring young people and containing multiple colors. Participants disliked advertisements perceived to portray misleading or contradictory messages, such as the promotion of physical activity or use of sex appeal, and ads perceived to lack authenticity. Identification of youth appealing features can help inform cannabis advertising regulations.

Unhealthy behaviors associated with mental health disorders: a systematic comparative review of diet quality, sedentary behavior, and cannabis and tobacco use

Background

There are well-established literatures documenting the associations between mental disorders and unhealthy behaviors such as poor diet quality, sedentary behavior, and cannabis and tobacco use. Few studies have attempted to understand the respective findings in light of each other, however.

Objective

The purpose of this review was to assemble comparable data for each behavior-disorder association and assess the associations in terms of their overall strength. The review aimed to include a representative, but not exhaustive, range of studies that would allow for explorative comparisons.

Methods

Eligible studies were identified via Pubmed searches and citation searching, restricted to publications no older than 2015 written in English. To obtain comparable data, only studies that reported findings as odds ratios were included, and risk of bias related to study samples, behavioral measurement disparities, and control variables was assessed via sensitivity analyses. Findings for each disorder were compared on the basis of different measures of central tendency.

Results

From 3,682 records, 294 studies were included. The review found evidence of associations between each of the four unhealthy behaviors and psychosis, depression, anxiety, bipolar disorder, attention-deficit/hyperactivity disorder (ADHD), and post-traumatic stress disorder (PTSD), while personality disorder was only investigated in relation to cannabis and tobacco use. In overall comparison, the associations were generally of similar strength, and only the association between cannabis use and personality disorder was exceptional in terms of being significantly stronger than its counterparts across disorders and across behaviors. Analyses of bias risk identified some influence from behavioral measurement disparities and lack of adequate statistical control, but findings were generally robust across a range of sensitivity analyses.

Conclusion

This explorative and comparative review found that poor diet quality, sedentary behavior, and cannabis and tobacco use are about equally strongly associated with a range of different mental disorders. Given the general nature of these associations, we should probably understand them to reflect a general and shared etiology. However, the findings in this review should be regarded as tentative until confirmed by more comprehensive investigations.

Legalization and retail availability of recreational marijuana and adolescent use in schools

Legalization of use and retail sales of recreational marijuana in U.S. states and the associated potential increase in access to marijuana and normalization of its use by adults could lead to increased use by adolescents. Studies have found that states with legal recreational marijuana have higher rates of adolescent use and frequency of use compared to states without legal use. We examined changes in student office discipline referrals (ODRs) for substance use offenses in Oregon middle and high schools before and after the legalization of recreational marijuana relative to comparison schools in other states. We found that rates of substance use related ODRs in middle schools increased by 0.14 per 100 students (30% of the mean) with legalization relative to comparison schools. This increase was moderated by the presence of a marijuana outlet within one mile of the school. We found no statistically discernible changes in high school ODRs. Marijuana use in adolescence has been linked to negative health and social consequences, including academic problems, mental health issues, and impaired driving. Potential adverse impact on adolescents and investments in school-based prevention programs could be important considerations for policymakers and public health officials when evaluating marijuana legalization.

Using EMA to explore the role of Black adolescents' experiences in activity spaces in momentary negative emotion and marijuana use

Research examining the role of place in Black adolescents' health behaviors typically examines neighborhoods, with little attention paid to micro geographies such as activity spaces. Understanding experiences in activity spaces may be especially important for Black adolescents living in neighborhoods traditionally characterized as disadvantaged. The SPIN project recruited 75 Black adolescents living in a single neighborhood to complete ecological momentary assessments (EMA) about the activity spaces they encountered over a month. Perceptions of violence and social support in activity spaces in a day are related to marijuana use during the day, relationships partially explained by negative momentary emotions.

Examination of the Relationship Between Daily Perceptions of Collective Efficacy and Marijuana Use Among Black Youth: Does the Location of the Perception Matters?

Neighborhood-level collective efficacy protects Black youth from substance use; however, neighborhood research does not account for the entirety of adolescents' exposure or their perceptions of space which may be critical to understanding the role of context in substance use. To address this limitation, the SPIN Project recruited 65 Black adolescents (M(SD) = 15.32(1.06)) to complete four brief surveys each day for a month describing their perceptions of spaces and marijuana use. Multilevel negative binomial models were estimated to test the relationship between an individual's perceptions of collective efficacy and the marijuana used during a day, and if the location of the observations moderated these relationships. Findings indicated that the perceptions of collective efficacy protected adolescents from marijuana use when occurring within their home neighborhood, but not outside of it; thereby suggesting important variations in adolescents' perceptions based on the location that matter for Black youth marijuana use.

Cohort Profile: The Woodlawn Study

The Woodlawn Study is an epidemiologically- defined community cohort study of 1242 Black Americans (51% female and 49% male), who were in first grade in 1966-67 in Woodlawn, a neighborhood of Chicago, Illinois. The study comprises extensive interview data over the life course including self-, mother-, and/or teacher-reported assessments at ages 6, 16, 32, 42, and 62 (in progress), administrative records (i.e., education, crime, and death records), and census data. These data cover a wide range of focal areas across the life course, including family environment, socioeconomic indicators, education, social integration (e.g., marriage, community engagement, religious involvement) and social support, employment, racial discrimination, substance use, crime/victimization, and mental and physical health, including mortality. Over the past 50 years, Woodlawn research has mapped cumulative disadvantage, substance use, and criminal offending and has identified key risk and protective factors of adversity, resilience, and success across the full life course. In turn, these findings have informed life course theory and policy for a population that experiences significant criminal and health disparities.

The moderating role of recreational substance use in the association of Mediterranean diet with academic performance among adolescents

No study has examined the potential moderating role of recreational substance use in the relationship between the Mediterranean diet (MedDiet) and academic performance. The aim of this study was to test the potential moderating role of recreational substance use (i.e., alcohol, tobacco, and cannabis) in the association of adherence to the MedDiet with academic performance among adolescents. This cross-sectional study included a sample of 757 adolescents (55.6% girls) aged 12-17 years from the Valle de Ricote (Region of Murcia). The Region of Murcia is an autonomous community of Spain located in the southeast of the Iberian Peninsula, along the coast of the Mediterranean Sea. Adherence to the MedDiet was assessed by the Mediterranean Diet Quality Index for Children and Teenagers (KIDMED). Recreational substance use (i.e., tobacco, alcohol, cannabis) was self-reported by adolescents. Academic performance was assessed by the school records at the end of the academic year. The relationship between adherence to the MedDiet and academic performance was moderated by both tobacco and alcohol use (for grade point average and all school records). In conclusion, higher adherence to the MedDiet was related to greater academic performance in adolescents, but recreational substance use could moderate this association.

The clouded debate: A systematic review of comparative longitudinal studies examining the impact of recreational cannabis legalization on key public health outcomes

Background

Ineffective cannabis regulatory frameworks such as prohibition have sparked interest in alternative solutions to reduce individual and societal harms. While it has been suggested that the recreational legalization process has yielded early successes, the relatively recent implementation of the novel policies has provided a modest time frame for a truly thorough establishment and assessment of key population-level indicators. The following systematic review focuses on identifying the downstream public health sequelae of cannabis legalization policies, including parameters such as cannabis consumption rates, hospitalization rates, vehicular accidents and fatalities, criminal activity, and suicidal behaviors, as well as other substance use trends.

Methods

An exhaustive search of the MEDLINE and Google Scholar databases were performed to identify high-quality (1) longitudinal studies, which (2) compared key public health outcomes between regions which had and had not implemented recreational cannabis legalization (RML) policies, (3) using distinct databases and/or time frames. Thirty-two original research articles were retained for review.

Results

Adult past-month cannabis consumption (26+ years) seems to have significantly increased following RML, whereas young adult (18-26 years) and adolescent (12-17 years) populations do not show a significant rise in past-month cannabis use. RML shows preliminary trends in increasing service use (such as hospitalizations, emergency department visits, or poisonings) or vehicular traffic fatalities. Preliminary evidence suggests that RML is related to potential increases in serious/violent crimes, and heterogeneous effects on suicidal behaviors. While the research does not illustrate that RML is linked to changing consumptions patterns of cigarette, stimulant, or opioid use, alcohol use may be on the rise, and opioid prescribing patterns are shown to be significantly correlated with RML.

Conclusion

The current data supports the notion that RML is correlated with altered cannabis consumption in adults, potentially increased criminal activity, and a decline in opioid quantities and prescriptions provided to patients. Future work should address additional knowledge gaps for vulnerable populations, such as individuals with mental health problems or persons consuming cannabis frequently/at higher THC doses. The effects of varying legalization models should also be evaluated for their potentially differing impacts on population-level outcomes.

Parallel latent trajectories of mental health and personal earnings among 16- to 20 year-old US labor force participants: a 20-year longitudinal study

PURPOSE

Determine the number of latent parallel trajectories of mental health and employment earnings over two decades among American youth entering the workforce and estimate the association between baseline sociodemographic and health factors on latent trajectory class membership.

METHODS

This study used data of 8173 participants from the National Longitudinal Survey of Youth 1997 who were 13-17 years old in 1997. Surveys occurred annually until 2011 then biennially until 2017, when participants were 33-37 years old. The Mental Health Inventory-5 measured mental health at eight survey cycles between 2000 and 2017. Employment earnings were measured annually between 1998 and 2017. Latent parallel trajectories were estimated using latent growth modeling. Multinomial logistic regression explored the association between baseline factors and trajectory membership.

RESULTS

Four parallel latent classes were identified; all showed stable mental health and increasing earnings. Three percent of the sample showed a good mental health, steep increasing earnings trajectory (average 2017 earnings ~ $196,000); 23% followed a good mental health, medium increasing earnings trajectory (average 2017 earnings ~ $78,100); 50% followed a good mental health, low increasing earnings trajectory (average 2017 earnings ~ $39,500); and 24% followed a poor mental, lowest increasing earnings trajectory (average 2017 earnings ~ $32,000). Participants who were younger, women, Black or Hispanic, from lower socioeconomic households, and reported poorer health behaviors had higher odds of belonging to the poor mental health, low earnings class.

CONCLUSION

Findings highlight the parallel courses of mental health and labor market earnings, and the influence of gender, race/ethnicity, and adolescent circumstances on these processes.

Preparedness for healthy ageing and polysubstance use in long-term cannabis users: a population-representative longitudinal study

BACKGROUND

Cannabis is often characterised as a young person's drug. However, people who began consuming cannabis in the 1970s and 1980s are no longer young and some have consumed it for many years. This study tested the preregistered hypothesis that long-term cannabis users show accelerated biological ageing in midlife and poorer health preparedness, financial preparedness, and social preparedness for old age.

METHODS

In this longitudinal study, participants comprised a population-representative cohort of 1037 individuals born in Dunedin, New Zealand, between April, 1972, and March, 1973, and followed to age 45 years. Cannabis, tobacco, and alcohol use and dependence were assessed at ages 18 years, 21 years, 26 years, 32 years, 38 years, and 45 years. Biological ageing and health, financial, and social preparedness for old age were assessed at age 45 years. Long-term cannabis users were compared using independent samples t tests with five groups: lifelong cannabis non-users, long-term tobacco users, long-term alcohol users, midlife recreational cannabis users, and cannabis quitters. In addition, regression analyses tested dose-response associations for continuously measured persistence of cannabis dependence from age 18 years to 45 years, with associations adjusted for sex, childhood socioeconomic status, childhood IQ, low childhood self-control, family substance dependence history, and persistence of alcohol, tobacco, and other illicit drug dependence.

FINDINGS

Of 997 cohort members still alive at age 45 years, 938 (94%) were assessed at age 45 years. Long-term cannabis users showed statistically significant accelerated biological ageing and were less equipped to manage a range of later-life health, financial, and social demands than non-users. Standardised mean differences between long-term cannabis users and non-users were large: 0·70 (95% CI 0·46 to 0·94; p<0·0001) for biological ageing, -0·72 (-0·96 to -0·49, p<0·0001) for health preparedness, -1·08 (-1·31 to -0·85; p<0·0001) for financial preparedness, and -0·59 (-0·84 to -0·34, p<0·0001) for social preparedness. Long-term cannabis users did not fare better than long-term tobacco or alcohol users. Tests of dose-response associations suggested that cannabis associations could not be explained by the socioeconomic origins, childhood IQ, childhood self-control, and family substance-dependence history of long-term cannabis users. Statistical adjustment for long-term tobacco, alcohol, and other illicit drug dependence suggested that long-term cannabis users' tendency toward polysubstance dependence accounted for their accelerated biological ageing and poor financial and health preparedness, although not for their poor social preparedness (β -0·10, 95% CI -0·18 to -0·02; p=0·017).

INTERPRETATION

Long-term cannabis users are underprepared for the demands of old age. Although long-term cannabis use appears detrimental, the greatest challenge to healthy ageing is not use of any specific substance, but rather the long-term polysubstance use that characterises many long-term cannabis users. Substance-use interventions should include practical strategies for improving health and building financial and social capital for healthy longevity.

FUNDING

The National Institute on Aging and the UK Medical Research Council. The Dunedin Research Unit is supported by the New Zealand Health Research Council and the New Zealand Ministry of Business, Innovation and Employment.

Explainable machine learning analysis reveals sex and gender differences in the phenotypic and neurobiological markers of Cannabis Use Disorder

Cannabis Use Disorder (CUD) has been linked to a complex set of neuro-behavioral risk factors. While many studies have revealed sex and gender differences, the relative importance of these risk factors by sex and gender has not been described. We used an “explainable” machine learning approach that combined decision trees [gradient tree boosting, XGBoost] with factor ranking tools [SHapley’s Additive exPlanations (SHAP)] to investigate sex and gender differences in CUD. We confirmed that previously identified environmental, personality, mental health, neurocognitive, and brain factors highly contributed to the classification of cannabis use levels and diagnostic status. Risk factors with larger effect sizes in men included personality (high openness), mental health (high externalizing, high childhood conduct disorder, high fear somaticism), neurocognitive (impulsive delay discounting, slow working memory performance) and brain (low hippocampal volume) factors. Conversely, risk factors with larger effect sizes in women included environmental (low education level, low instrumental support) factors. In summary, environmental factors contributed more strongly to CUD in women, whereas individual factors had a larger importance in men.

Adult Psychiatric, Substance, and Functional Outcomes of Different Definitions of Early Cannabis Use

OBJECTIVE

Research on associations of early cannabis use with adult functioning reports mixed findings. This may be due, in part, to wide variations in the definitions of early cannabis use. This study aims to compare associations of 4 commonly used definitions of early cannabis use-related to timing, dose, duration, and associated symptoms-with adult outcomes.

METHOD

Analyses were based on a 20⁺-year longitudinal, community-representative study of 1,420 participants. Between ages 9 and 21 years (8,806 observations), participants were assessed for cannabis use and DSM-5 cannabis use disorder. In early adulthood (ages 24-26 and 30; 2,424 observations of 1,266 subjects), participants were also assessed for psychiatric, substance use, and functional outcomes.

RESULTS

All definitions of early use were associated with multiple adult outcomes in models that adjusted for sex and race/ethnicity. In models that also adjusted for childhood psychiatric problems and family adversities, only daily use and a persistent developmental subtype (defined as daily/problematic use that began in adolescence and continued into early adulthood) were associated with later substance use/disorders, poorer functional outcomes, and derailments in the transition to adulthood.

CONCLUSION

Daily, continued-over-time cannabis use beginning on adolescence was most problematic for a range of adult outcomes. Cessation of early use did not fully eliminate later risks; but was associated with fewer negative outcomes, with weaker effect sizes.

The Relations between Youth Cannabis Use, School Cannabis Use-Related Disciplinary Approaches and Student Perceptions of School Support

Background: In the school year immediately following cannabis legalization in Canada, this paper investigated youth perceptions of school support for the prevention and cessation of substance use. Scant research has examined student perceptions in relation to school disciplinary approaches. This study was the first to classify school discipline approach styles using school-level measures.Objective: The objective of this study was to examine whether different school cannabis use-related disciplinary approaches are associated with student cannabis use and perceptions of school supportiveness for the prevention and cessation of substance use.Results: School- and student-level survey data from Year 7 (the 2018/2019 school year) of the COMPASS study were used, including 68,037 grade 9-12 (Secondary I-V in Quebec) students attending 131 Canadian secondary schools. Schools were classified as using different cannabis use-related disciplinary styles based on school-administrator reported approaches to student first-offense violations of school cannabis policies. We identified that although none of the cannabis use-related disciplinary approach styles examined were associated with cannabis use, they were associated with student perceptions. Students attending schools classified as using a Permissive/Supportive approach had a higher likelihood of perceiving their school as supportive for substance use prevention/cessation than their peers at Authoritarian schools. Students who perceived their school as supportive for substance use prevention/cessation were less likely to report current cannabis use than their peers who perceived their school as unsupportive.Conclusions: Unlike previous studies using school classification styles that are based on student perceptions, results do not support direct associations between school cannabis use-related disciplinary styles and student cannabis use. Future prospective research should examine whether supportive disciplinary approaches (e.g., counseling referrals, educational programs) promote student perceptions of school supportiveness, and in turn, deter student substance use.

Prospective Associations of Discrimination, Race, and Sexual Orientation with Substance Use in Adolescents

Objective: Adolescents are at high risk for alcohol and cannabis use. Emerging evidence suggests that discrimination exposure is prospectively associated with risk for alcohol use among adolescents of marginalized race, sexual orientation, or gender identity. However, it is unknown whether prospective discrimination-substance use associations among marginalized adolescents are also present for cannabis use. This study examined prospective associations of race, sexual orientation, and discrimination exposure with alcohol and cannabis use over one year. Methods: Data were drawn from a two-wave longitudinal health survey study of 9-11^th graders (n = 350 for the current analyses; Year 1 M_age=15.95 [SD = 1.07, range = 13-19]; 44% male; 44% Black, 22% White, 18% Asian, 16% Multiracial; 16% LGB; 10% Hispanic/Latinx ethnicity) at an urban high school. Two multinomial logistic regressions examined associations of Year 1 race, sexual orientation, and discrimination experiences with Year 2 alcohol and cannabis consumption separately. Results: Year 1 Discrimination exposure was associated with increased risk for Year 2 past-year alcohol use among Asian (OR = 1.34) and past-month alcohol use among Multiracial (OR = 1.30) adolescents, but not Black or LGB adolescents. Discrimination exposure was not associated with any cannabis use pattern in any group. Independent of discrimination, LGB adolescents were at greater risk for monthly alcohol (OR = 3.48) and cannabis use (OR = 4.07) at Year 2. Conclusions: Discrimination exposure is prospectively associated with risk for alcohol use among adolescents of understudied (Asian, Multiracial) racial backgrounds, and should be considered in alcohol prevention and intervention strategies. Risk factors for alcohol and cannabis use among LGB adolescents should continue to be explored.

A Content Analysis of Cannabis Company Adherence to Marketing Requirements in Four States

OBJECTIVE

Marketing messages can influence adolescents' attitudes and behaviors toward alcohol and tobacco. In the era of legalized cannabis use, retail cannabis companies often use social media marketing on platforms popular among youth. The purpose of this study was to evaluate adherence to state-based regulations for restricted and required content across social media from recreational cannabis businesses.

METHOD

A retrospective content analysis was used to evaluate one year of publicly displayed posts by retail cannabis companies on Facebook and Instagram from four states in which recreational cannabis use is legal (Alaska, Colorado, Oregon, and Washington State). We evaluated restricted content including the following: (a) business practices, such as avoiding discounts/promotions or promoting branded products; (b) modeling cannabis use or overconsumption; (c) youth-focused messaging; and (d) health benefits. We evaluated required content including three types of warnings: (a) limiting cannabis use to those age 21 and over, (b) avoiding impaired driving, and (c) describing health risks.

RESULTS

A total of 2,660 posts were evaluated from 14 businesses. In the area of restricted content, discounts/promotions were present in approximately 35% of all posts. Another common category was overconsumption, found in 12% of posts. Required content regarding warnings was present in less than half of all social media posts.

CONCLUSIONS

Despite state-based advertising restrictions, recreational cannabis business pages use messages with youth appeal. Required safety message adherence is not typical on social media business pages.

A Content Analysis of Cannabis Company Adherence to Marketing Requirements in Four States

OBJECTIVE

Marketing messages can influence adolescents' attitudes and behaviors toward alcohol and tobacco. In the era of legalized cannabis use, retail cannabis companies often use social media marketing on platforms popular among youth. The purpose of this study was to evaluate adherence to state-based regulations for restricted and required content across social media from recreational cannabis businesses.

METHOD

A retrospective content analysis was used to evaluate one year of publicly displayed posts by retail cannabis companies on Facebook and Instagram from four states in which recreational cannabis use is legal (Alaska, Colorado, Oregon, and Washington State). We evaluated restricted content including the following: (a) business practices, such as avoiding discounts/promotions or promoting branded products; (b) modeling cannabis use or overconsumption; (c) youth-focused messaging; and (d) health benefits. We evaluated required content including three types of warnings: (a) limiting cannabis use to those age 21 and over, (b) avoiding impaired driving, and (c) describing health risks.

RESULTS

A total of 2,660 posts were evaluated from 14 businesses. In the area of restricted content, discounts/promotions were present in approximately 35% of all posts. Another common category was overconsumption, found in 12% of posts. Required content regarding warnings was present in less than half of all social media posts.

CONCLUSIONS

Despite state-based advertising restrictions, recreational cannabis business pages use messages with youth appeal. Required safety message adherence is not typical on social media business pages.

Associations of Cannabis Use across Adolescence and Early Adulthood With Health and Psychosocial Adjustment in Early Adulthood and Midadulthood in Men

Background:

Associations between men’s prior cannabis use and their physical and psychosocial adjustment were examined using prospective data across adolescence (ages 13-20 years), early adulthood (ages 20-30 years), and midadulthood (ages 30-38 years). The theoretical framework was based in developmental-contextual and lifespan approaches.

Method:

Models were tested using men in the Oregon Youth Study who had been studied since ages 9 to 10 years and who, in childhood, lived in neighborhoods with higher than average rates of delinquency. Cannabis use in adolescence was used to predict early adult outcomes (and early adult use to midadult outcomes). In addition, a set of covariates was added to the models, including childhood risk factors assessed at age 9 years (ie, family socioeconomic status; externalizing behaviors; and if available, the childhood proxy for the outcome [eg, age 9 intelligence scale]) and alcohol use in adolescence (or early adulthood). physical health outcomes included accidental injuries, problems resulting from a prior injury, body mass index, self-report health, and also pain and cardiovascular risk (blood pressure and pulse rate) in midadulthood. Psychosocial outcomes included income, housing insecurity, intelligence, depressive symptoms, psychosis symptoms, hostility/aggression, social problems, and attention problems.

Results:

Whereas there was almost no prediction from prior cannabis use to the physical health outcomes, there were comprehensive associations of cannabis use from the prior developmental period and psychosocial outcomes in both early adulthood and midadulthood.

Conclusion:

Cannabis use in prior developmental periods was associated with a broad range of types of poor psychosocial adjustment in adulthood.

High Prevalence and Early Onsets: Legal and Illegal Substance Use in an Urban Cohort of Young Adults in Switzerland

INTRODUCTION

Debates about the legalization of illegal substances (e.g., cannabis) continue around the globe. A key consideration in these debates is the adequate protection of young people, which could be informed by current prevalence and age-of-onset patterns. For Switzerland, such information is limited, which is particularly true for women, despite advanced political efforts to legalize cannabis. The objective of the current study was to investigate substance use prevalence rates and ages of onset in a community-representative sample of female and male young adults in Switzerland.

METHODS

Data came from the Zurich Project on the Social Development from Childhood to Adulthood (z-proso). In 2018, participants (N = 1,180, 50.8% females) were ∼20 years old. Lifetime and past-year use of alcohol, tobacco, cannabinoids, stimulants, hallucinogens, opioids, and benzodiazepines were assessed with an extensive substance use questionnaire. Additionally, ages of onsets of the respective substances were estimated by averaging participants' self-reported ages of onsets from ages 13 to 20 (max. 4 assessments).

RESULTS

57% of 20-year-olds had used cannabinoids, 16% stimulants, 15% opioids (mostly codeine), and 8% hallucinogens in the past year. Males had higher prevalence than females for most drugs; nevertheless, females' prevalence rates were notably high. Legal substance use was typically initiated 1.3-2.7 years before legal selling age. Thus, almost half of the sample had consumed alcohol and tobacco by age 14. More than 40% of the total sample had smoked cannabis by age 16. Males initiated use of legal substances and cannabis earlier than females.

DISCUSSION

Our recent community-representative data suggested unexpectedly high levels and early onsets of substance use compared to a previous Swiss surveys and also the European average. Drug policy debates should consider urban substance use patterns when considering legalization efforts.

Variations of cannabis-related adverse mental health and addiction outcomes across adolescence and adulthood: A scoping review

INTRODUCTION

Evidence supporting associations between cannabis use and many health outcomes is growing, however it remains unclear how such associations vary across the lifespan. We therefore aim to answer the following questions: (1) Are the risks of cannabis's adverse effects on mental health and addiction-related outcomes different in adolescents than in adults? (2) What are the relationships between these cannabis's adverse effects and (a) an individual's age at first cannabis use, (b) age at assessment, and (c) duration of cannabis use?

METHODS

We searched Medline, Embase, CINAHL, and PsychINFO from inception to 18 October 2021. Two reviewers independently screened studies and descriptively synthesized results.

RESULTS

We included 140 studies. Cannabis effects on mental health and addiction-related outcomes were worse in adolescents, early cannabis initiators and cannabis users who consumed for longest periods. Evidence of worse long-term adverse effects in adolescents was substantial for psychosis, cannabis, and nicotine use disorders; mixed for depression, suicidality, other substance use and disorders; and limited for anxiety. Additionally, acute cannabis exposure had the opposite trend with adults more often reporting adverse effects than adolescents.

CONCLUSION

The available evidence suggests that cannabis use should be delayed as late as possible in adulthood and shortened in duration across the lifespan to decrease the risk of negative outcomes, while emphasizing the need for adapted harm reduction approaches. This scoping review provides evidence on the role of age and duration of exposure as determinants of cannabis-related adverse effects, which may inform prevention and harm reduction strategies.

SYSTEMATIC REVIEW REGISTRATION

https://doi.org/10.17605/OSF.IO/BYG72.

Cannabinoids for the treatment of cannabis use disorder: New avenues for reaching and helping youth?

Cannabis use peaks during adolescence and emerging adulthood, and cannabis use disorder (CUD) is associated with a wide range of adverse outcomes. This is particularly pertinent in youth, because the developing brain may be more vulnerable to adverse effects of frequent cannabis use. Combining evidence-based psychosocial interventions with safe and effective pharmacotherapy is a potential avenue to improve youth outcomes, but we lack approved CUD pharmacotherapies. Here, we review new potential avenues for helping youth with CUD, with a particular focus on cannabinoid-based treatments. Evidence from placebo-controlled RCTs suggests synthetic delta-9-tetrahydrocannabinol (THC) decreases withdrawal symptoms, but not cannabis use, in adults with daily cannabis use/CUD, while findings regarding formulations containing THC combined with cannabidiol (CBD) are mixed. Preliminary evidence from two placebo-controlled RCTs in adults with CUD suggests that both Fatty Acid Amide Hydrolase inhibitors and CBD can reduce cannabis use. However, larger trials are needed to strengthen the evidence. Findings from adults point to cannabinoid-based treatments as a potential strategy that should be examined in youth with CUD.

Frequent teenage cannabis use: Prevalence across adolescence and associations with young adult psychopathology and functional well-being in an urban cohort

BACKGROUND

Amidst cannabis legalization efforts and laws, we do not fully understand how the youngest frequent cannabis users fare during young adulthood. This study aims to 1) examine the prevalence of cannabis use during adolescence, and 2) investigate links of frequent (i.e., weekly or daily) teenage cannabis use with psychopathology and functional well-being at age 20-compared to no or occasional use.

METHODS

Data came from a prospective-longitudinal cohort study (assessments from 2004 to 2018, from ages 7-20) in an urban setting (N = 1482). Substance use was assessed with self-reports between ages 13 and 20. At age 20, participants reported on psychopathology (psychotic symptoms, problematic substance use, aggression, and internalizing symptoms) and functional well-being (delinquency, financial difficulties, social exclusion, general well-being, and not being in education, employment, or training). Covariates were based on self-, parent-, teacher-, and behavioral measures.

FINDINGS

Almost one in five adolescents had used cannabis frequently between ages 13 and 17 (26.6% of males, 9.8% of females). Adjusting nearly 20 potential confounders, frequent teenage cannabis use was associated with age 20 problematic substance use and poorer functional well-being compared to the no cannabis use and the occasional use groups. Frequent teenage cannabis use was more consistently associated with age 20 functional outcomes compared to frequent teenage nicotine or alcohol use.

CONCLUSIONS

Frequent teenage cannabis use was common and associated with problematic substance use, more delinquency, and poorer functional well-being at age 20. Accordingly, frequent teenage cannabis users could experience increased difficulties in mastering the transitions of young adulthood.

Greenspace programmes for mental health: A survey study to test what works, for whom, and in what circumstances

The health benefits of greenspace are widely acknowledged. Greenspace programmes, defined as health programmes undertaken in outside green areas such as parks, gardens, hills, and forests, are becoming more commonplace. However, there is still limited understanding of the mechanisms by which greenspace programmes are effective. This makes future development and implementation very difficult. We recently developed and published a novel framework for greenspace programmes for mental health showing what works, for whom, and in what circumstances (Masterton et al., 2020). In this current study, the accuracy of the proposed framework was tested for the first time using primary data from greenspace organisations in Scotland. Given the link between mental health and substance use, the applicability of the framework to programmes that support people with problem substance use was also tested. A survey was designed to test the contexts, mechanisms, and outcomes identified within the previously proposed framework. The survey was completed by 64 participants to provide a general overview of the framework's applicability for programmes that support mental health, as well as for programmes that support people with problem substance use. Overall, respondents agreed with all survey statements. This suggests that the framework does effectively represent the underlying context, mechanism, outcome configurations of greenspace programmes for mental health. Furthermore, there were no differences between responses from organisations that support people with problem substance use, and organisations that do not support this client group. This shows that the framework has the potential to be applicable to both greenspace programmes for mental health and greenspace programmes for people with problem substance use. This is a novel finding as, to our knowledge, there is currently no framework looking to explain the contexts, mechanisms, and outcomes necessary for greenspace programmes to be successful for people with problem substance use.

Initiation of Moderately Frequent Cannabis use in Adolescence and Young Adulthood is Associated with Declines in Verbal Learning and Memory: A Longitudinal Comparison of Pre- versus Post-Initiation Cognitive Performance

OBJECTIVE

Cannabis use is associated with relative cognitive weaknesses as observed by cross-sectional as well as longitudinal research. Longitudinal studies, controlling for relevant confounds, are necessary to differentiate premorbid from post-initiation contributions to these effects.

METHODS

We followed a sample of adolescents and young adults across ten years. Participants provided neurocognitive data and substance use information at two-year intervals. Participants who initiated cannabis and/or alcohol use were identified (n = 86) and split into alcohol-only initiators (n = 39) and infrequent (n = 29) and moderately frequent (n = 18) cannabis initiators. Participants completed the Rey Auditory Verbal Learning Task (RAVLT) and the Iowa Gambling Task (IGT). Group differences before and after substance use initiation and the extent to which alcohol, nicotine, and cannabis use frequencies contributed to cognitive functions over time were examined.

RESULTS

After controlling for parental education, RAVLT new learning was worse in moderately frequent cannabis users prior to use initiation. RAVLT total learning and delayed recall showed significant declines from pre- to post-initiation in moderately frequent cannabis users. Regression analyses confirmed that frequencies of cannabis, but not alcohol, use contributed to post-initiation variations. Nicotine use showed an independent negative association with delayed memory. Findings for the IGT were not significant.

CONCLUSIONS

Verbal learning and memory may be disrupted following the initiation of moderately frequent cannabis use while decreased new learning may represent a premorbid liability. Our use of a control group of alcohol-only users adds interpretive clarity to the findings and suggests that future studies should carefully control for comorbid substance use.

Voucher Reinforcement Decreases Psychiatric Symptoms in Young People in Treatment for Drug Use Disorders - A Post Hoc Secondary Analysis of a Randomized Controlled Trial

OBJECTIVE

This multicenter, parallel randomized, open study examined the effect of using vouchers and session reminders as an added element to outpatient treatment for drug use disorders in youth. It was hypothesized that being randomly assigned to a contingency management condition would lead to a reduction of psychiatric symptoms, and that this reduction would be mediated through abstinence and treatment completion.

METHODS

A total of 460 participants aged 15 to 25 years from nine outpatient sites were randomized to one of four treatment conditions (standard treatment alone [STD], i.e., 12 sessions using motivational interviewing and cognitive behavioral therapy, STD plus vouchers for attendance [VOU], STD plus text reminders [REM], or STD plus vouchers and text reminders [REM + VOU]). Participants' symptoms of psychological distress were assessed using the YouthMap 12 instrument at intake, and at 3, 6, and 9 months post-treatment initiation. Interviewers were blinded to interventions.

RESULTS

114 participants were randomized to STD, 112 to REM, 113 to VOU, and 121 to VOU + REM. 69 clients were never interviewed for follow-up, leaving 391 for analysis (n = 90, n = 94, n = 99, n = 108). The mean age was 20.5 years (SD = 2.6), 23% were female, and 34% reported having a psychiatric diagnosis. Random effects regression showed that participants randomized to one of the two voucher-based conditions experienced significantly steeper declines in symptoms compared with STD (p < .01). Structural equation modeling results indicated that the effects of contingency management on symptoms were mediated through abstinence, but not sessions attended.

CONCLUSIONS

Adding contingency management to interventions for drug use disorders can reduce symptoms of psychological and emotional distress among populations of treatment-seeking youth, in part due to indirect effects through abstinence at follow-up. The data is collected from a clinical trial registered as ISRCTN27473213, at https://www.isrctn.com/.

Disciplinary Approaches for Cannabis Use Policy Violations in Canadian Secondary Schools

The objective of this study was to examine the disciplinary approaches being used in secondary schools for student violations of school cannabis policies. Survey data from 134 Canadian secondary schools participating in the Cannabis use, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) study were used from the school year immediately following cannabis legalization in Canada (2018/19). Despite all schools reporting always/sometimes using a progressive discipline approach, punitive consequences (suspension, alert police) remain prevalent as first-offence options, with fewer schools indicating supportive responses (counselling, cessation/educational programs). Schools were classified into disciplinary approach styles, with most schools using Authoritarian and Authoritative approaches, followed by Neglectful and Permissive/Supportive styles. Further support for schools boards in implementing progressive discipline and supportive approaches may be of benefit.

Vouchers versus reminders to prevent dropout: Findings from the randomized youth drug abuse treatment project (youthDAT project)

BACKGROUND

Over the last few decades, evidence-based treatments for emerging adults with drug use disorder (DUD) have been developed, but dropout and inconsistent session attendance persist. This study assessed the efficacy of voucher reinforcement and/or text reminders for treatment attendance and completion in emerging adults with DUD in Denmark.

METHODS

The study compared four levels of treatment intensity, with participants randomly assigned to standard outpatient counseling only (STD), outpatient counseling plus vouchers for attendance (VOU), outpatient counseling plus text reminders (REM), or outpatient counseling plus vouchers and text reminders (REM + VOU). A total of 460 individuals aged 15-25 years seeking treatment for DUD were randomly assigned to the four treatment conditions across nine sites.

RESULTS

STD counseling had the lowest completion rate (25%), followed by REM (39%), VOU (46%), and REM + VOU (49%). Additionally, post hoc comparisons indicated that clients randomized to the REM + VOU condition differed in terms of zero no-shows from clients who were randomized to the VOU condition (χ2(1) = 6.90, p = 0.009) and the REM condition (χ2(1) = 5.87, p = 0.015).

CONCLUSIONS

Vouchers and text reminders contribute to reduced dropout and increased treatment attendance in emerging adults with DUD. The combination of vouchers and reminders in particular has the potential to reduce the number of no-shows.

Are School Substance Use Policy Violation Disciplinary Consequences Associated with Student Engagement in Cannabis?

Schools are increasingly concerned about student cannabis use with the recent legalization in Canada; however, little is known about how to effectively intervene when students violate school substance use policies. The purpose of this study is to assess the disciplinary approaches present in secondary schools prior to cannabis legalization and examine associations with youth cannabis use. This study used Year 6 (2017/2018) data from the COMPASS (Cannabis use, Obesity, Mental Health, Physical Activity, Alcohol use, Smoking, Sedentary behavior) study including 66,434 students in grades 9 through 12 and the 122 secondary schools they attend in British Columbia, Alberta, Ontario, and Quebec. Student questionnaires assessed youth cannabis use and school administrator surveys assessed potential use of 14 cannabis use policy violation disciplinary consequences through a ("check all that apply") question. Regression models tested the association between school disciplinary approaches and student cannabis use with student- (grade, sex, ethnicity, tobacco use, binge drinking) and school-level covariates (province, school area household median income). For first-offence violations of school cannabis policies, the vast majority of schools selected confiscating the product (93%), informing parents (93%), alerting police (80%), and suspending students from school (85%), among their disciplinary response options. Few schools indicated requiring students to help around the school (5%), issuing a fine (7%), or assigning additional class work (8%) as potential consequences. The mean number of total first-offence consequences selected by schools was 7.23 (SD = 2.14). Overall, 92% of schools reported always using a progressive disciplinary approach in which sanctions get stronger with subsequent violations. Students were less likely to report current cannabis use if they attended schools that indicated assigning additional class work (OR 0.57, 95% CI (0.38, 0.84)) or alerting the police (OR 0.81, 95% CI (0.67, 0.98)) among their potential first-offence consequences, or reported always using the progressive discipline approach (OR 0.77, 95% CI (0.62, 0.96)) for subsequent cannabis policy violations. In conclusion, results reveal the school disciplinary context in regard to cannabis policy violations in the year immediately preceding legalization. Various consequences for cannabis policy violations were being used by schools, yet negligible association resulted between the type of first-offence consequences included in a school's range of disciplinary approaches and student cannabis use.

[Cannabis use among the drug users with compulsory detained detoxification treatment in China]

OBJECTIVE

To explore the epidemic situation of cannabis use among drug users with compulsory detained detoxification treatment in China.

METHODS

Using the data from the Drug Abuse Population Estimation in the Key Cities of the Ministry of Public Security, we analyzed the sociodemographic characteristics and substance use of cannabis abusers with compulsory detained detoxification treatment in 55 provincial capital cities and key cities of China. Chi-square test, Fisher exact test and Kruskal-Wallis rank sum test were used to compare the prevalence of cannabis, heroin, synthetic and mixed drug use among patients with detoxification treatment, as well as the differences in polydrug use and areas among cannabis users.

RESULTS

In the study, 25 366 drug users with compulsory detained detoxification treatment were recruited, of whom 2.2% (546/25 366) used cannabis in the previous year before the treatment. The proportion of males was 83.5%, and the proportion of ethnic minorities was 41.0%. Those who received junior high school education or above accounted for 30.8%, and the unemployed accounted for 44.1%. The average age was (33.3±8.2) years, the average age of beginning drug use was (24.8±7.7) years, and the average duration between the first drug abuse and first detoxification treatment was (5.4±4.6) years. The prevalence of cannabis use was higher among those drug users who were 35-year-old and younger, ethnic minorities, employees and residents in Xinjiang. Of the cannabis users, 91.4% used polydrug, 13.6% combined with heroin alone, 42.1% combined with synthetic drugs alone and 35.7% combined with both of heroin and synthetic drugs. Of the cannabis users, 49.6% came from 3 regions: Xinjiang Uygur Autonomous Region, Jiangsu Province and Shanghai City. The cannabis users in Xinjiang had a high proportion of ethnic minorities who received junior high school education and below. Moreover, 79.6% of them combined cannabis use with heroin. The cannabis users in Jiangsu, Zhejiang and Shanghai areas had a higher proportion of ethnic Han who received better education (high school and above). Moreover, 92.7% of them combined cannabis use with methamphe-tamine.

CONCLUSION

The prevalence of cannabis use among the population with compulsory detained detoxification treatment is higher than that among drug users under surveillance, but there are obvious regional cluster effect and high possibility of polydrug abuse. Thus, it's important to strengthen the monitoring of cannabis use, to increase the control of cannabis and to formulate China's anti-cannabis policy among different population.

Electronic nicotine delivery system use is related to higher odds of alcohol and marijuana use in adolescents: Meta-analytic evidence

Research suggests that electronic nicotine delivery system (ENDS) use is associated with other substance use in adolescents; however, the magnitude of this association and whether this differs between adolescents and adults is not yet well understood. This meta-analysis aimed to quantify the extent to which ENDS use is associated with alcohol and marijuana use among adolescents and to compare the odds across adolescent samples and a comparison group of adult samples. A comprehensive literature review was conducted examining the relationship between ENDS use and alcohol (adolescent k = 40 from 19 independent studies; adult k = 35 from 12 independent studies) and marijuana (adolescent k = 24 from 14 independent studies; adult k = 6 from 3 independent studies) use. Adolescents who use ENDS had greater odds of reporting co-occurring alcohol use (OR = 4.50, p < .001), particularly binge drinking (OR = 4.51), and marijuana use (OR = 6.04, p < .001) than adolescent who did not use ENDS. Adults who use ENDS were also more likely to use alcohol (OR = 1.57, p < .001) and marijuana (OR = 2.04, p < .001) than those who did not use ENDS. ENDS use was associated with significantly greater odds of alcohol use (log odds ratio; LOR = 0.96 (OR = 2.61), p < .001) and a trend of greater marijuana use (LOR = 0.93 (OR = 2.53), p = 0.08) in adolescents than in adults. Effects were large in adolescents and small in adults. Findings suggest that ENDS use should be assessed in adolescents in both research and clinical settings. Importantly, ENDS use is strongly associated with co-occurring alcohol or marijuana use in adolescents.

Interventions to Prevent Illicit and Nonmedical Drug Use in Children, Adolescents, and Young Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Illicit and nonmedical (use in ways other than instructed) drug use is common in adolescents and young adults and increases the risk of harmful outcomes such as injuries, violence, and poorer academic performance.

OBJECTIVE

To review the benefits and harms of interventions to prevent illicit and nonmedical drug use in children, adolescents, and young adults to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMED, PsycINFO, and the Cochrane Central Register of Controlled Trials (January 1, 2013, to January 31, 2019 [children and adolescents]; January 1, 1992, to January 31, 2019 [young adults <25 years]); surveillance through March 20, 2020.

STUDY SELECTION

Clinical trials of behavioral counseling interventions to prevent initiation of illicit and nonmedical drug use among young people.

DATA EXTRACTION AND SYNTHESIS

Critical appraisal was completed independently by 2 investigators. Data were extracted by 1 reviewer and checked by a second. Random-effects meta-analysis was used to estimate the effect sizes associated with the interventions.

MAIN OUTCOMES AND MEASURES

Number of times illicit drugs were used; any illicit drug or any cannabis use.

RESULTS

Twenty-nine trials (N = 18 353) met inclusion criteria. Health, social, or legal outcomes such as mental health symptoms, family functioning, consequences of drug use, and arrests were reported in 19 trials and most showed no group differences. The effects on illicit drug use in 26 trials among nonpregnant youth (n = 17 811) were highly variable; the pooled result did not show a clinically important or statistically significant association with illicit drug use (standardized mean difference, -0.08 [95% CI, -0.16 to 0.001]; 24 effects [from 23 studies]; n = 12 801; I2 = 57.0%). The percentage of participants using illicit drugs ranged from 2.3% to 38.6% in the control groups and 2.4% to 33.7% in the intervention groups at 3 to 32 months' follow-up. The median absolute risk difference between groups was -2.8%, favoring the intervention group (range, -11.5% to 14.8%). The remaining 3 trials provided a perinatal home-visiting intervention to pregnant Native American youth. One trial (n=322) found a reduction in illicit drug use at 38 months (eg, cannabis use in the previous month, 10.7% in the intervention group and 15.6% in the control group) but not at earlier follow-up assessments. Across all 29 trials, only 1 trial reported on harms and found no statistically significant group differences.

CONCLUSIONS AND RELEVANCE

The evidence for behavioral counseling interventions to prevent initiation of illicit and nonmedical drug use among adolescents and young adults was inconsistent and imprecise, with some interventions associated with reduction in use and others associated with no benefit or increased use. Health, social, and legal outcomes were sparsely reported, and few showed improvements.

Primary Care-Based Interventions to Prevent Illicit Drug Use in Children, Adolescents, and Young Adults: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

In 2017, an estimated 7.9% of persons aged 12 to 17 years reported illicit drug use in the past month, and an estimated 50% of adolescents in the US had used an illicit drug by the time they graduated from high school. Young adults aged 18 to 25 years have a higher rate of current illicit drug use, with an estimated 23.2% currently using illicit drugs. Illicit drug use is associated with many negative health, social, and economic consequences and is a significant contributor to 3 of the leading causes of death among young persons (aged 10-24 years): unintentional injuries including motor vehicle crashes, suicide, and homicide.

OBJECTIVE

To update its 2014 recommendation, the USPSTF commissioned a review of the evidence on the potential benefits and harms of interventions to prevent illicit drug use in children, adolescents, and young adults.

POPULATION

This recommendation applies to children (11 years and younger), adolescents (aged 12-17 years), and young adults (aged 18-25 years), including pregnant persons.

EVIDENCE ASSESSMENT

Because of limited and inadequate evidence, the USPSTF concludes that the benefits and harms of primary care-based interventions to prevent illicit drug use in children, adolescents, and young adults are uncertain and that the evidence is insufficient to assess the balance of benefits and harms. More research is needed.

RECOMMENDATION

The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of primary care-based behavioral counseling interventions to prevent illicit drug use, including nonmedical use of prescription drugs, in children, adolescents, and young adults. (I statement).

Do Differences in Learning Performance Precede or Follow Initiation of Marijuana Use?

OBJECTIVE

Studies examining cross-sectional associations between age at marijuana initiation and memory deficits yield mixed results. Because longitudinal data are sparse, controversy continues regarding whether these deficits reflect premorbid risk factors or sequelae of early marijuana initiation; here, we examine this question in a community sample followed since birth.

METHOD

Masked examiners administered four subtests of the Wide Range Assessment of Memory and Learning (WRAML/WRAML2) from childhood until young adulthood to 119 urban, predominantly African American participants. Multivariable generalized estimated equation models measured longitudinal trajectories of learning. Participants were grouped as never users (n = 26), later initiators (≥16 years old; n = 31), and earlier initiators of marijuana use (n = 62).

RESULTS

Marijuana onset groups did not significantly differ on WRAML scaled scores or IQ in childhood, nor did they differ on WRAML scaled scores in adolescence. On most WRAML2 subtests, these groups did not significantly differ in young adulthood after taking into account sex and childhood IQ. However, on Story Memory, later initiators attained higher scaled scores in young adulthood, even after including additional covariates of anxiety, depression, postsecondary education, past-month marijuana use, and past-week high-risk drinking. They showed a significantly more positive trajectory than never users that was driven by within-group improvement after adolescence. Earlier initiators showed within-group decline in Story Memory after adolescence.

CONCLUSIONS

Differences in learning following earlier initiation of marijuana use may not be solely attributable to premorbid deficits.

Effects of Adolescent Cannabis Use on Motivation and Depression: A Systematic Review

Purpose of review

This article reviews recent behavioral and neuroimaging studies to elucidate whether adolescent cannabis use is related to reduced motivation and increased risk of depression.

Recent findings

Recent work suggests that heavy adolescent cannabis use predicts poorer educational outcomes, often presumed to reflect reduced academic motivation, as well as increased levels of depressive symptoms. However, evidence of a link between cannabis use and general motivation was lacking. Factors such as concurrent alcohol and tobacco use, trajectories of cannabis use during adolescence, and cannabis-related changes in underlying neurocircuitry may impact associations among cannabis use, motivation, and depression.

Summary

Heavy adolescent cannabis use is associated with poorer educational outcomes and increased levels of depressive symptoms. The role of depression in how cannabis may affect motivation, broadly, is not yet clear, as most studies have not examined associations among all three constructs. Future work should explore possible overlap between cannabis effects on motivation and depression, and clarify the temporality of these associations.

Commentary on Terry-McElrath et al. (2019): Will persistent patterns of youth marijuana use compromise their futures?

Recent increases in the prevalence of frequent marijuana use that extend well into adulthood raise concerns about the long-term consequences for population health and for the individuals engaging in these use patterns.

Cannabinoids therapeutic use: what is our current understanding following the introduction of THC, THC:CBD oromucosal spray and others?

INTRODUCTION

The complexity of the endocannabinoid (eCB) system is becoming better understood and new drivers of eCB signaling are emerging. Modulation of the activities of the eCB system can be therapeutic in a number of diseases. Research into the eCB system has been paralleled by the development of agents that interact with cannabinoid receptors. In this regard it should be remembered that herbal cannabis contains a myriad of active ingredients, and the individual cannabinoids have quite distinct biological activities requiring independent studies. Areas covered: This article reviews the most important current data involving the eCB system in relation to human diseases, to reflect the present (based mainly on the most used prescription cannabinoid medicine, THC/CBD oromucosal spray) and potential future uses of cannabinoid-based therapy. Expert commentary: From the different therapeutic possibilities, THC/CBD oromucosal spray has been in clinical use for approximately five years in numerous countries world-wide for the management of multiple sclerosis (MS)-related moderate to severe resistant spasticity. Clinical trials have confirmed its efficacy and tolerability. Other diseases in which different cannabinoids are currently being investigated include various pain states, Alzheimer's disease, Parkinson's disease, Huntington's disease and epilepsy. The continued characterization of individual cannabinoids in different diseases remains important.