Adolescent Cannabis Use Research Articles

Navigating the Grey Zone: The Impact of Legislative Frameworks in North America and Europe on Adolescent Cannabis Use-A Systematic Review.

This paper aims to systematically review the impact of legislative framework changes in North America and Europe on adolescent cannabis use. It not only seeks to examine the prevalence of adolescent marijuana use following legislative changes but also to identify the driving forces behind fluctuations in use and to address the gaps left by previous studies. A systematic literature review was conducted in selected databases. After screening English-language publications dating from 2013 to 2023 (n = 453 studies), 24 met the inclusion criteria. Articles were considered if they analyzed the impact of legislative changes on adolescent cannabis use in countries across North America and Europe. The overall findings suggest an inconsistency regarding the prevalence of cannabis use among youth and adolescents following policy changes. The effects of modifications in cannabis policies on marijuana consumption are complex and influenced by various factors. These include the details of legislation, societal perspectives, enforcement methods, socioeconomic status, and cultural background. The results of this analysis reveal a nuanced reality. Although research suggests a rise in cannabis use after legalization, there are variations in the outcomes observed. This highlights the significance of considering context and demographics. Moreover, studies shed light on how specific policy changes, such as depenalization, can affect cannabis use.

A test of competing mediators linking trouble sleeping to cannabis use in adolescents and emerging adults.

This study examined day-level associations between trouble sleeping and three cannabis-use indices (likelihood/quantity of use and impaired control). We evaluated behavioral and cognitive mediators of the association between trouble sleeping and cannabis outcomes. Youth (N = 86, ages 15-24, 48.8% female, 58.8% White, 18.6% Latine) who regularly used cannabis were recruited for an intervention study. This preregistered secondary data analysis leveraged data from a 1-week ecological momentary assessment (EMA) study completed prior to intervention. Trouble sleeping, cannabis use, and impaired control over use were assessed each morning; negative affect, risk-taking propensity, and cannabis craving were assessed multiple times and aggregated to create a daily average. Multilevel structural equation modeling evaluated hypothesized temporally sequenced associations and putative mechanisms at the day (i.e., within) and person (i.e., between) level. In bivariate analyses at the person level, there were large-effect associations between trouble sleeping and craving and negative affect, and between craving and cannabis-use likelihood and quantity (rs from .34 to .48). In multilevel analyses at the day level, participants were less likely to use cannabis the next day after reporting more trouble sleeping (β = -.65, p < .001). Trouble sleeping was not directly associated with subsequent cannabis-use quantity or impaired control, or indirectly via negative affect, risk-taking propensity, or craving. Trouble sleeping had differential relations with cannabis-use indices at the day and person levels. To promote youth health and reduce cannabis use, future research may consider the unique, person- and situation-driven mechanistic processes at play. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Hippocampal gray matter volume in young adulthood varies with adolescent alcohol use.

Adolescent substance use is linked with negative future outcomes (e.g., depression, anxiety, substance use disorder). Given that the brain undergoes significant maturation during adolescence, this developmental period may represent a time of particular vulnerability to substance use. Neuroimaging research has largely focused on heavy or binge patterns of substance use; thus, relatively less is known about the neural impact of a broader range of adolescent substance use. Characterizing the neural impact of a broader range of adolescent substance use may inform prevention and treatment efforts. The present study investigated relationships between adolescent substance use trajectories (i.e., alcohol, tobacco, and cannabis) and gray matter volume in young adulthood. Substance use was assessed in 1,594 participants at ages 11, 13, 16, and 19. Following the last assessment, 320 participants completed a single magnetic resonance imaging session to assess brain gray matter volume. Latent growth curve models were used to estimate growth parameters characterizing alcohol, tobacco, and cannabis use trajectories for each participant. These growth parameters (i.e., intercept, linear slope, and quadratic slope) were then used as predictors of gray matter volume. The gray matter volume of the hippocampus was positively associated with age 14 alcohol use (i.e., intercept) but not other trajectories (i.e., progression or acceleration) or substances (tobacco or cannabis). These results provide new insight into the neural impact of distinct adolescent alcohol, tobacco, and cannabis use trajectories, which may help to refine prevention and treatment efforts. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

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 = 5mg 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.

Adolescent and Young Adult Cannabis Use: Aberrant Functional Activation in the Context of Affective Processing

Adolescent and Young Adult Cannabis Use: Aberrant Functional Activation in the Context of Affective Processing

Clinician perspectives on adolescent cannabis-related beliefs and behaviors following recreational cannabis legalization

BackgroundAs more states legalize cannabis, studies are needed to understand the potential impacts of recreational cannabis legalization (RCL) on adolescents from the perspective of clinicians who care for them. MethodsThis qualitative study characterized clinician perspectives on whether cannabis legalization is associated with changes in adolescents’ cannabis use beliefs, behaviors, and consequences. Semi-structured qualitative interviews were conducted with 32 clinicians in a large healthcare organization from 9/6/2022–12/21/2022. Video-recorded interviews were transcribed and analyzed using thematic analysis. ResultsThe 32 participants (56.3 % female, mean [SD] age, 45.9 [7.6] years; 65.3 % non-Hispanic White) were from Addiction Medicine (n = 13), Psychiatry/Mental Health (n = 7), Pediatrics (n = 5), and the Emergency Department (n = 7). Clinicians described post-RCL increases in adolescent cannabis use, use of non-combustible modes and high-potency products, and younger age of first use. Clinicians reported social, physical, and policy changes, including changes in social norms, appealing advertisements, marketing, and easier access. Many noted fewer perceived harms among adolescents and greater self-medication post-RCL. They described how RCL contributed to increased parental cannabis use and permissiveness around adolescent use. Finally, many described post-RCL increases in cannabis hyperemesis syndrome, and several noted increased cannabis-related psychosis and acute intoxication, and decreased court-mandated treatment. ConclusionsClinicians from diverse specialties described post-RCL increases in adolescent cannabis use and cannabis-related consequences, alongside changes in social norms, access, marketing and advertisements, and decreased perceptions of harms. Findings can inform strategies to support adolescents in the context of increased cannabis availability and acceptability post-legalization and support the development of hypotheses for broader-scale quantitative work.

Investigating sex differences and age of onset in emotion regulation, executive functioning, and cannabis use in adolescents and young adults

BackgroundYoung adults have historically high levels of cannabis use at a time which coincides with emotional and cognitive development. Age of regular onset of cannabis use and sex at birth are hypothesized to influence the relationship between cannabis use and cognition. Here we investigated past 6-month cannabis use in relation to emotional and executive functioning. We further considered age of onset and sex in subgroup analyses.MethodYoung adults (N = 225; ages 16–22) completed a substance use interview and cognitive battery, including the Emotional Word-Emotional Face Stroop and NIH toolbox executive functioning tasks. Linear regressions examined relationships between past 6-month cannabis use episodes and performance. Subgroup analyses investigated whether age of onset or sex impacted relationships.ResultsAfter correcting for multiple comparisons, greater past 6-month cannabis use episodes were related to poorer Emotional Stroop Congruent Accuracy (p = .0004, FDR-p = .002) and List Sorting Working Memory (p = .02, FDR-p = .10) performance. Younger age of regular use onset marginally related to lower Emotional Stroop Congruent Accuracy performance (p = .03, FDR-p = .13). There were no cannabis use by sex interactions on cognition.ConclusionsConsistent with prior findings, results suggest small reductions in cannabis-related performance in processing speed during emotional Stroop and working memory tasks. Age of onset was modestly related to Stroop performance, but not sex. Longitudinal studies which detail patterns of cannabis and other substance use are needed to better assess brain-behavior relationships and other factors (e.g., age of onset of regular use, sex) which could influence cannabis-related impairments in cognitive functioning.

Alerta Cannabis: A Tailored-Computer Web-Based Program for the Prevention of Cannabis Use in Adolescents: A Cluster-Randomized Controlled Trial Protocol

BackgroundThe growing use of cannabis in adolescence is a public health problem that must be addressed through prevention. In Spain, the average age of initiation of cannabis use in the adolescent population is 14.8 years. At 14 years, the lifetime prevalence of cannabis use is 11.7%, which increases to 51.,5% at the age of 18; the prevalence of cannabis use in the population aged 14 to 18 years is 28.6%, a figure that must be tried to reduce, that is why this school prevention program is proposed: Alerta Cannabis.MethodsThe Alerta Cannabis research project consists of design, implementation, and evaluation. In the first phase, a computer-tailored eHealth program (Alerta Cannabis) is developed based on the I-Change Model, an integrated model based on three main behavioral change processes: awareness, motivation, and action. This program consists of four 30-minute sessions that will provide culturally adapted and personalized advice to motivate students not to use cannabis through text feedback, animations, and gamification techniques. This phase will also include usability testing. In the implementation phase, secondary school students from Western Andalusia, Spain (Seville, Cádiz, Huelva, and Córdoba) and Eastern Andalusia (Jaén, Málaga, and Granada) will be randomized to an experimental condition (EC) or a control condition (CC) for a cluster randomized clinical trial (CRCT). Each condition will have 35 classes within 8 schools. GI will receive the online intervention Alerta Cannabis. EC and CC will have to fill out a questionnaire at baseline, six months, and twelve months of follow-up. In the last phase, the effect of Alerta Cannabis is evaluated. The primary outcomes are the lifetime prevalence of cannabis use and its use in the last 30 days and at 6 months. At 12 months of follow-up, the prevalence in the last 12 months will also be assessed. The secondary outcome is the intention to use cannabis.DiscussionThe study tests the effect of the innovative program specifically aimed to reduce the use of cannabis in the adolescent population through eHealth in Spain. The findings aim to develop and implement evidence-based cannabis prevention interventions, which could support school prevention, for instance, the assistance of school nurses. If the program proves to be effective, it could be useful to prevent cannabis use on a national and international scale.Trial registrationNCT05849636. Date of registration: March 16, 2023.

Nicotine and Alcohol Use as Predictors of Recreational Cannabis Use in Adolescence: A Systematic Review and Narrative Synthesis

Background: The prevalence of recreational cannabis use among adolescents is a growing public health concern due to its link to short- and long-term adverse effects on adolescents’ wellbeing, physical health, mental health, and interpersonal behaviors. Method: Five databases were searched from inception to March 17, 2023, for exposure (nicotine product, alcohol) and outcome (recreational cannabis) in adolescents (persons aged 10–19 years). The studies were screened independently by two reviewers, and the quality of the studies was assessed with Newcastle Ottawa and AXIS tool. PRISMA guidelines were employed in this review. Result: Twenty-one (21) studies involving 2,778,406 adolescents were included in the appraisal and heterogeneity was found among these studies. Ascertainment bias was commonly detected in thirteen (13) of the included studies. Among the substances examined as potential exposures, nicotine-product use emerged as a significant factor associated with future cannabis use among adolescents, particularly in mid-adolescence and in places where recreational cannabis use has been legalized. Conclusion: Current evidence suggests an association between nicotine-product use and subsequent recreational cannabis use among adolescents. However, further research is needed to establish causality between exposure to nicotine substances and the use of recreational cannabis within this age demographic. Additionally, there is a need for the development of prevention programs and targeted policies that continuously inform and update this vulnerable sub-population about the risks associated with cannabis use for leisure.

Impact of intrinsic and extrinsic religiosity on cannabis use in adolescents: A structural equation modelling approach to data from the National Survey on Drug Use and Health (NSDUH) 2015–2019

IntroductionReligiosity is believed to be a factor that may reduce the risk of addiction and substance use both in adults and in young people. It is a complex construct that is neither measurable nor objectifiable, thus it must be estimated from proxy characteristics. For this purpose, researchers differentiate between subjective religiosity (i.e., individual religious experience) and extrinsic religiosity, that is, participation to religious services (extrinsic-personal subtype) or to social activities consistent with religion-based principles (extrinsic-social subtype).Objectives This work aimed at exploring the role of different facets of religiosity – intrinsic (subjective), extrinsic-personal (service attendance), and extrinsic-social (church-based social activities) – in terms of deterring cannabis use among adolescents.Methods Aggregated data of NSDUH (2015-2019) on 68,263 adolescents between 12 and 17 years of age were analysed using a structural equation modelling (SEM) to determine pathways of intrinsic and extrinsic components of religiosity in cannabis use. Several covariates were considered in the analyses, including comorbid depression and civil volunteering activities.Results About 15% of participants admitted cannabis use in the previous year. Intrinsic and extrinsic-personal religiosity was reported by 66% and 25% of the sample, respectively. A percentage of fifty-seven of participants were involved in at least one faith-based activity, while 74% reported participation in secular community activities. Both intrinsic and extrinsic-personal religious components were likely to reduce cannabis use at the SEM regression model analysis controlling for putative confounders (cannabis use coeff.: -0.065, p=0.001; coeff.: -0.176, p&lt;0.001, respectively). Considering the joint contribution of relevant covariates (community-based activities, lifetime MDE, sex, and poverty status), the outputs were similar. Cannabis use was not influenced by extrinsic-social component of religiosity, even though the involvement in non-faith based volunteering activities was protectively associated.ConclusionsFrom a policy-makers perspective, the reduction of cannabis use among young people may be obtained by supporting secular volunteering programs, which seem to be a cost-effective strategy. Moreover, whilst promoting religiosity is beyond the scope of any preventive programs, religious practices should be considered relevant protective factors.Disclosure of InterestNone Declared

Recoverability and estimation of causal effects under typical multivariable missingness mechanisms.

In the context of missing data, the identifiability or "recoverability" of the average causal effect (ACE) depends not only on the usual causal assumptions but also on missingness assumptions that can be depicted by adding variable-specific missingness indicators to causal diagrams, creating missingness directed acyclic graphs (m-DAGs). Previous research described canonical m-DAGs, representing typical multivariable missingness mechanisms in epidemiological studies, and examined mathematically the recoverability of the ACE in each case. However, this work assumed no effect modification and did not investigate methods for estimation across such scenarios. Here, we extend this research by determining the recoverability of the ACE in settings with effect modification and conducting a simulation study to evaluate the performance of widely used missing data methods when estimating the ACE using correctly specified g-computation. Methods assessed were complete case analysis (CCA) and various implementations of multiple imputation (MI) with varying degrees of compatibility with the outcome model used in g-computation. Simulations were based on an example from the Victorian Adolescent Health Cohort Study (VAHCS), where interest was in estimating the ACE of adolescent cannabis use on mental health in young adulthood. We found that the ACE is recoverable when no incomplete variable (exposure, outcome, or confounder) causes its own missingness, and nonrecoverable otherwise, in simplified versions of 10 canonical m-DAGs that excluded unmeasured common causes of missingness indicators. Despite this nonrecoverability, simulations showed that MI approaches that are compatible with the outcome model in g-computation may enable approximately unbiased estimation across all canonical m-DAGs considered, except when the outcome causes its own missingness or causes the missingness of a variable that causes its own missingness. In the latter settings, researchers may need to consider sensitivity analysis methods incorporating external information (e.g., delta-adjustment methods). The VAHCS case study illustrates the practical implications of thesefindings.

Neurite Orientation Dispersion and Density Imaging (NODDI) of Brain Microstructure in Adolescent Cannabis and Nicotine Use.

Despite evidence suggesting deleterious effects of cannabis and nicotine tobacco product (NTP) use on white matter integrity, there have been limited studies examining white matter integrity among users of both cannabis and nicotine. Further, updated white matter methodology provides opportunities to investigate use patterns on neurite orientation dispersion and density (NODDI) indices and subtle tissue changes related to the intra- and extra-neurite compartment. We aimed to investigate how cannabis and NTP use among adolescents and young adults interacts to impact the white matter integrity microstructure. A total of 221 participants between the ages of 16 and 22 completed the Customary Drinking and Drug Use Record (CDDR) to measure substance use, and underwent a magnetic resonance imaging (MRI) session. Participants were divided into NTP-control and NTP groupings and cannabis-control and cannabis groupings (≥26 NTP/cannabis uses in past 6 months). Tract-Based Spatial Statistics (TBSS) and two-way between-subjects ANOVA investigated the effects of NTP use group, cannabis use group, and their interaction on fractional anisotropy (FA) and NODDI indices while controlling for age and biological sex. NTP use was associated with decreased FA values and increased orientation dispersion in the left anterior capsule. There were no significant effects of cannabis use or the interaction of NTP and cannabis use on white matter outcomes. NTP use was associated with altered white matter integrity in an adolescent and young adult sample. Findings suggest that NTP-associated alterations may be linked to altered fiber tract geometry and dispersed neurite structures versus myelination, as well as differential effects of NTP and cannabis use on white matter structure. Future work is needed to investigate how altered white matter is related to downstream behavioral effects from NTP use.

Can we predict adolescent cannabis use? A Bayesian semi-parametric approach to project future trends

Despite its decrease in many Western countries, cannabis remains the most used illicit substance among adolescents. This study aims to summarize cannabis consumption during the last two decades and project trends among 15-year-olds in the 2021–22 HBSC survey. A Bayesian semi-parametric hierarchical model was adopted to estimate the trend of cannabis consumption using data of about 287,000 adolescents from the 2001/2002 to the 2017/2018 HBSC wave and the 38 countries that met the inclusion criteria. Data show an overall decline in most countries for both boys and girls. However, in 22 countries of 38 cannabis use is expected to increase again in our projection. The discussion of these findings should take into account cultural, policy, social factors and unpredictable events such as the Covid-19 pandemic, that can significantly impact future trends leading to discrepancies between the projected and observed values. However, these discrepancies can provide insight into understanding the potential impact of preventive strategies and the underlying processes responsible for changes in cannabis use over time.

Perceived risk of harm and school commitment as protective factors of cannabis use in a school-based survey of adolescents

Cannabis is one of the most used substances by adolescents in the United States and is associated with adverse effects. In general, previous research has focused on risk rather than protective factors for adolescent cannabis use. A focus on protective factors can lead to improving strengths-based prevention programs. For the current study, we reviewed the literature and selected a set of protective factors that have relevance for preventing cannabis use in adolescents. We tested these factors with a large sample of adolescents within a single analytic model that allowed for making comparisons among protective factors as well as replicating findings from prior research. Adolescent data came from a large school-based survey study of students (n = 32,626) in grades 6, 8, 10, and 12 conducted in the state of Utah. Logistic regression analysis indicated that adolescents reporting higher endorsement of perceived risk of harm for using cannabis, school commitment, and family management had significantly greater odds of being in the non-using cannabis group for the past 30-days compared to youth with lower endorsement of these factors. In contrast, prosocial involvement and school opportunities were not associated with past 30-day cannabis use in the analytical model. Implications for the perceived risk of harm, school commitment, and family management in relation to strengths-based preventive strategies are discussed.

Risk and Promotive Factors Related to Cannabis Use Among American Indian Adolescents.

Reservation-dwelling American Indian adolescents are at exceedingly high risk for cannabis use. Prevention initiatives to delay the onset and escalation of use are needed. The risk and promotive factors approach to substance use prevention is a well-established framework for identifying the timing and targets for prevention initiatives. This study aimed to develop predictive models for the usage of cannabis using 22 salient risk and promotive factors. Models were developed using data from a cross-sectional study and further validated using data from a separate longitudinal study with three measurement occasions (baseline, 6-month follow-up, 1-year follow-up). Application of the model to longitudinal data showed an acceptable performance contemporaneously but waning prospective predictive utility over time. Despite the model's high specificity, the sensitivity was low, indicating an effective prediction of non-users but poor performance in correctly identifying users, particularly at the 1-year follow-up. This divergence can have significant implications. For example, a model that misclassifies future adolescent cannabis use could fail to provide necessary intervention for those at risk, leading to negative health and social consequences. Moreover, supplementary analysis points to the importance of considering change in risk and promotive factors over time.

Why Are Adolescent Cannabis Use Disorder Treatment Admissions Declining in the US? The Mediated Pathway of State Treatment Admissions Rates before and after Recreational Cannabis Legalization

Purpose: State-level prevalence data are used to investigate whether recreational cannabis legalization moderates the mediated pathway from the perception of low risk of harm, to cannabis use, to cannabis use disorder (CUD) treatment admissions, among adolescents (age 12–17) in the US. Methods: Annual state prevalence measures of perception of low risk, cannabis use, and CUD treatment admissions between 2008 and 2019 (N = 542 state-year observations) were collected from the National Survey on Drug Use and Health (NSDUH) and the Treatment Episode Dataset – Admissions (TEDS-A). A two-way fixed effects (state and year) moderated mediation model was used to test whether recreational legalization moderated the indirect effect of perception of low risk on treatment admissions via cannabis use. Results: A positive indirect effect of perceiving cannabis as low risk on CUD treatment admissions via cannabis use was observed prior to legalization but not afterwards. After legalization, the positive association of perceiving cannabis as low risk with cannabis use was strengthened, and the positive association of cannabis use with treatment admissions was suppressed, as compared to before legalization. Discussion: Recreational legalization may alter the social acceptability and medical self-administration of cannabis, potentially leading to CUD treatment utilization decline among adolescents even as risk factors for CUD increase. Linking recreational cannabis legalization to advancing awareness of the health risks associated with adolescent cannabis use and promoting adolescent CUD treatment engagement through mHealth approaches and primary care providers are key to addressing potential adolescent health challenges brought about by expanding cannabis legalization.

Adolescent alcohol and cannabis use and early adulthood educational attainment in the 1986 Northern Finland birth cohort study

BackgroundHeavy alcohol and cannabis use during adolescence have been previously described as risk factors not only for morbidity in adulthood, but also social problems including adversities in educational attainment. Attempts to consider overlapping risk factors and confounders for these associations are needed.MethodsUsing weighted multivariable models, we examined prospective associations between age at first drink (AFD), age at first intoxication (AFI), frequency of alcohol intoxication, as well as self-reported alcohol tolerance (i.e., number of drinks needed for the subjective experience of intoxication), and lifetime cannabis use at age 15/16 years with subsequent educational attainment obtained from comprehensive registers until age 33 in the Northern Finland Birth Cohort 1986 (6,564 individuals, 49.1% male). Confounding variables including sex, family structure (intact vs. non-intact), maternal and paternal education level, behavioural/emotional problems in school at age 7/8 years, having a history of illicit substance use in adolescence, having any psychiatric diagnosis before age 16, and parental psychiatric diagnoses, were adjusted for.ResultsIn this large birth cohort study with a 17-year follow-up, younger age at first intoxication, higher frequency of alcohol intoxication, and high self-reported alcohol tolerance at age 15/16 years were associated with poorer educational outcomes by the age of 33 years. These associations were evident regardless of potential confounders, including parental education and childhood behavioural/emotional problems. The association between adolescent cannabis use and educational attainment in adulthood was no longer statistically significant after adjusting for confounders including frequency of alcohol intoxication at age 15/16.ConclusionsAssessments of age of first alcohol intoxication, high self-reported alcohol tolerance and frequency of intoxication during adolescence should be included when implementing screening strategies aimed at identifying adolescents at risk for subsequent social problems.

Effects of Cannabis Exposure on Adolescent Health and Development: A Narrative Review

Abstract: Adolescence is an immature but adventurous time period of exploration. Due to rapid developments of the brain with unbalanced release of neurotransmitters, adolescents are prone to impulsivity that may carry out potentially dangerous behaviors. According to the Centers for Disease Control and Prevention, more than one-third of high school students have reported the use of cannabis or marijuana in 2019, and the trend has not declined since. Previous studies have shown that cannabis not only affects cognitive and social behaviors, but also produces psychological responses to stress. In this review, we have summarized recent studies on cannabis- produced effects during the unique period of adolescent development, and we have also briefly discussed the legalization of cannabis. Though there are slight differences between cannabis and marijuana, the major active component of them is tetrahydrocannabinol. We have used the term “cannabis” in this review. Cannabis use in adolescents causes structural and functional changes in the brain, increasing the probability of depression, which is also associated with other illicit substance use, and impairs education achievement. Given that cannabis use can cause detrimental harm to adolescents, it is suggested that adolescents should generally avoid using cannabis in a recreational manner. More preclinical and clinical studies are needed to provide detailed information for evidence-based decisions.

Sex Differences in Response-Contingent Cannabis Vapor Administration During Adolescence Mediate Enduring Effects on Behavioral Flexibility and Prefrontal Microglia Activation in Rats.

Introduction: Cannabis is the most used illicit drug in the United States. With many states passing legislation to permit its recreational use, there is concern that cannabis use among adolescents could increase dramatically in the coming years. Historically, it has been difficult to model real-world cannabis use to investigate the causal relationship between cannabis use in adolescence and behavioral and neurobiological effects in adulthood. Materials and Methods: We used a response-contingent vapor administration model to investigate long-term effects of cannabis use during adolescence on the medial prefrontal cortex (mPFC) and mPFC-dependent behaviors in male and female rats. Results: Adolescent (35- to 55-day-old) female rats had significantly higher rates of responding for vaporized Δ9-tetrahydrocannabinol (THC)-dominant cannabis extract (CANTHC) compared with adolescent males. In adulthood (70-110 days old), female, but not male, CANTHC rats also took more trials to reach criterion and made more regressive errors in an automated attentional set-shifting task compared with vehicle rats, thereby indicating sex differences in behavioral flexibility impairments. Notably, sex-treatment interactions were not observed when rats of each sex were exposed to a noncontingent CANTHC vapor dosing regimen that approximated CANTHC vapor deliveries earned by females. No differences were observed in effort-based decision making in either sex. In the mPFC, female (but not male) CANTHC rats displayed more reactive microglia with no changes in myelin basic protein expression or dendritic spine density. Conclusion: Altogether, these data reveal important sex differences in rates of responding for CANTHC vapor in adolescence that may confer enduring alterations to mPFC structure and function and suggest that there may be subtle differences in the effects of response-contingent versus noncontingent cannabis exposure that should be systematically examined in future studies.

Associations between cannabis use, opioid misuse and severe psychological distress in adolescents: A cross-sectional school-based study

BackgroundCannabis use and nonmedical use of prescription opioids are consumed by a small to moderate number of adolescents. However, little is known about their combined influence on mental health in this age group. This study examined the association between cannabis use, nonmedical use of prescription opioids, or both with serious psychological distress among adolescents and tested if sex could moderate these associations. MethodsWe based our analyses on cross-sectional data from the 2019 Ontario Student Drug Use and Health Survey, a provincially representative sample of students in grades 7 through 12 (aged 11–20 years or older) across Ontario, Canada (n= 7097; mean age: 15.2 ± 1.2 years). Logistic regression analyses were adjusted for important covariates. ResultsWe found that 20.5% reported cannabis use only, 5.8% reported opioid use only, and 5% reported both cannabis and opioid use. Cannabis use only (odds ratio [OR]:1.91; 95% confidence interval [CI]:1.53–2.37), opioid use only (OR: 2.21; 95% CI: 1.63–3.00), and both cannabis and opioid use (OR: 3.24; 95% CI: 2.25–4.66) were associated with greater odds of serious psychological distress after adjustment for covariates. Associations were similar for males and females. ConclusionThe use of both cannabis and opioids is significantly associated with serious psychological distress among adolescents. Adolescents who use both cannabis and opioids represent a small and vulnerable group that should be targeted in future interventions against mental health problems. Health professionals should consider screening for polysubstance use, especially when working with adolescents who use cannabis.