Recent rapid decrease in adolescents' perception that marijuana is harmful, but no concurrent increase in use

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

BACKGROUND

As 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.

METHODS

This 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.

RESULTS

The 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.

CONCLUSIONS

Clinicians 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.

Independent and concurrent cannabis use with alcohol, cigarettes, and other substances among college students: Rates and consequences

Objective: The purpose of this study was to examine patterns of concurrent cannabis and other substance use and their differential associations with cannabis-related problems and academic outcomes in college students. Participants: Participants were undergraduate students (N = 263; M age = 19.1 years; 61.2% female) who were eligible if they used cannabis at least 3 days in the past month (M = 10.1 days). Method: Substance use, academic-related outcomes, and measures of Cannabis Use Disorder (CUD) severity and problems were obtained in an online survey. Results: The five groups evaluated were cannabis-only users (5.3%), cannabis and alcohol (47.1%), cannabis, alcohol and cigarettes (16.7%), cannabis, alcohol and other substances (14.8%), or all-substances (16%). Cannabis-only and all-substance users reported using cannabis most frequently (ps ≤ .034), but only the latter reported greater CUD severity, problems, and poorer academic outcomes. Discussion: College student polysubstance users may be at increased risk for poorer outcomes compared to cannabis-only users and other groups.

Adolescents' Cannabis Knowledge and Risk Perception: A Systematic Review

To systematically review evidence evaluating cannabis-related knowledge and perception of risk in children and adolescents. We systematically searched Medline, PsycINFO, and EMBASE using Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. 133 studies from around the world (including ages 10-18 yrs) met inclusion criteria, with 70% meeting grade 2C quality. Increased knowledge and perception of risk of cannabis frequently correlated with lower levels of current use and intent to use. Studies examining correlations over time generally demonstrated increased adolescent cannabis use and decreased perception of risk. Included prevention-based interventions often enhanced knowledge and/or perception of risk in adolescents exposed to the intervention. Studies exploring outcomes relating to legislative changes for recreational marijuana use demonstrated considerable heterogeneity regarding knowledge and perception of risk whereas studies that focused on medicinal marijuana legislative changes overwhelmingly demonstrated a decrease in perception of risk post legalization. Increased knowledge and perception of risk of cannabis in adolescents often correlate with lower levels of current use and intention to use in the future. Further study and implementation of public health and clinically-oriented strategies that seek to increase knowledge among youth about the potential health harms of cannabis use should continue and be prioritized.

Birth, cognitive and behavioral effects of intrauterine cannabis exposure in infants and children: A systematic review and meta-analysis

BACKGROUND AND AIMS

Δ9-tetrahydrocannabinol (THC), the principal psychoactive component of cannabis, has been implicated in affecting fetal neurodevelopment by readily crossing the placenta. However, little is known regarding the long-term effects of intrauterine cannabis exposure. This systematic review and meta-analysis synthesized prospective and cross-sectional human studies to measure the effects of intrauterine cannabis exposure on birth, behavioral, psychological and cognitive outcomes in infancy until early childhood.

METHODS

Reporting according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, cross-sectional and prospective studies published from database inception until June 2023, investigating developmental outcomes of infants, toddlers and young children with intrauterine cannabis exposure were considered. All articles were obtained from PubMed or PsycINFO databases.

RESULTS

The literature search resulted in 932 studies, in which 57 articles met eligibility criteria. The meta-analysis revealed that intrauterine cannabis exposure increases the risk of preterm delivery [odds ratio (OR) = 1.68, 95% confidence interval (CI) = 1.05-2.71, P = 0.03], low birth weight (OR = 2.60, CI = 1.71-3.94, P < 0.001) and requirement for neonatal intensive care unit (NICU) admission (OR = 2.51, CI = 1.46-4.31; P < 0.001). Our qualitative synthesis suggests that intrauterine cannabis exposure may be associated with poorer attention and externalizing problems in infancy and early childhood. We found no evidence for impairments in other cognitive domains or internalizing behaviors.

CONCLUSIONS

Prenatal cannabis use appears to be associated with lower birth weight, preterm birth and neonatal intensive care unit admission in newborns, but there is little evidence that prenatal cannabis exposure adversely impacts behavioral or cognitive outcomes in early childhood, with the exception of attention and externalizing problems.

Chronic Pain and Cannabis Use Frequency, Intensity, and Severity in Young Adults

BACKGROUND

Cannabis use is common among young adults and is associated with many physical and mental health problems. Persons with chronic pain may be particularly susceptible to using cannabis at high rates, including for analgesic purposes, thus exposing themselves to greater risk of cannabis-related problems. However, little research has examined connections between chronic pain and cannabis use in the young adult population.

MATERIALS AND METHODS

Participants were young adults from the community who were recruited for a larger health behaviors study. The present sample included 403 persons from this larger sample who reported cannabis use in the past 90 days. Participants completed measures of demographic characteristics, cannabis and alcohol use, and chronic pain.

RESULTS

This young adult sample reported using cannabis on an average of 47.1 of the past 90 days, and 20.1% reported chronic pain. Chronic pain was associated with greater cannabis use frequency (IRR = 1.35, 95%CI 1.15; 1.57, p < 0.001), intensity (IRR = 1.61, 95%CI 1.18; 2.21, p = 0.003), and negative consequences (IRR = 1.23, 95%CI 1.02; 1.48, p < 0.030).

DISCUSSION

In this sample of young adults who use cannabis, chronic pain was significantly associated with frequent, intense cannabis use, as well as more cannabis-related negative consequences. These findings suggest that chronic pain may be a marker for a particularly high-risk pattern of cannabis use in this age group, thus identifying an especially vulnerable subset of young adults who may require heightened research and clinical attention.

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.

The effect of marijuana use in adolescence on college and graduate degree attainment

We estimate the long-term effect of using marijuana in adolescence on college and graduate degree attainment measured approximately 20 years later. We rely on the first two waves (1994-1996) and the fifth wave (2016-2018) of the National Longitudinal Study of Adolescent to Adult Health and estimate instrumental variables models that exploit the network structure at the second degree by using marijuana use status of friends of friends who are not themselves friends of the respondent in order to instrument for the respondent's marijuana use. Our models also include school and grade fixed effects. Marijuana use in adolescence leads to a large reduction in the likelihood of college and graduate degree attainment by the time respondents are aged 33-43 years old.

Associations between Adolescent Marijuana Use, Driving after Marijuana Use and Recreational Retail Sale in Colorado, USA

OBJECTIVE

We investigated associations between the retail distribution of recreational marijuana in Colorado and (i) past 30-day marijuana use and (ii) driving after marijuana use (DAMU) among a representative sample of public high school students using four waves of data from a state surveillance system.

METHODS

Past 30-day marijuana use was assessed among all sampled students (n = 85,336). DAMU was assessed among students 15 years or older who indicated driving (n = 47,518). Modified Poisson regression with robust variance estimates was used to estimate prevalence ratios (PR) comparing the pre-distribution (2013) and post-distribution (2015, 2017, 2019) periods for marijuana-related behaviors. Frequency of behavioral engagement was assessed using a multinomial approach.

RESULTS

An estimated 20.3% of students engaged in past 30-day marijuana use and 10.5% of student drivers engaged in DAMU. Retail distribution of recreational marijuana was not significantly associated with the prevalence of any marijuana use or DAMU. However, it was associated with 1.16 (95% CI: 1.04-1.29) times the prevalence of using marijuana one or two times in the last 30 days, 1.27 (1.03, 1.55) times the prevalence of DAMU one time, and 0.82 (0.69, 0.98) times the prevalence of DAMU six or more times. No significant associations were observed for the remaining frequency categories.

CONCLUSIONS

Approximately 1 in 10 students who drive reported DAMU. Varying prevalence in the frequency of past 30-day marijuana use and DAMU was observed following the retail distribution of recreational marijuana in Colorado. Care should be taken to properly educate adolescent drivers regarding the dangers of DAMU.

A Review of the Effects of Adolescent Cannabis Use on Physical Health

The current review highlights the available research related to cannabis and indicators of physical health in a variety of domains. Various studies have found associations between cannabis use with pulmonary, cardiovascular, gastrointestinal, and endocrine function as well as body mass index and sleep. At this time, more research is needed to understand the influence of cannabis use on physical health, particularly among adolescent samples.

Consequences of adolescent drug use

Substance use in adolescence is a known risk factor for the development of neuropsychiatric and substance use disorders in adulthood. This is in part due to the fact that critical aspects of brain development occur during adolescence, which can be altered by drug use. Despite concerted efforts to educate youth about the potential negative consequences of substance use, initiation remains common amongst adolescents world-wide. Additionally, though there has been substantial research on the topic, many questions remain about the predictors and the consequences of adolescent drug use. In the following review, we will highlight some of the most recent literature on the neurobiological and behavioral effects of adolescent drug use in rodents, non-human primates, and humans, with a specific focus on alcohol, cannabis, nicotine, and the interactions between these substances. Overall, consumption of these substances during adolescence can produce long-lasting changes across a variety of structures and networks which can have enduring effects on behavior, emotion, and cognition.

Dealing with Zeros: Adolescent Drug Use, Perceived Disapproval, and Perceived Harm

Because studies examining youth drug use often have data with a high proportion of zeros, they often do not meet the assumptions for univariate or linear regression analyses that are typically used. We demonstrate the use of zero-inflated negative binomial regression models to address excessive zeros in drug use frequency on perceptions of disapproval and perceived harm among middle and high school students (N = 522). We found that perceptions of parent disapproval were a better predictor of marijuana use (p = .01) than peer disapproval. Perceived harm was related to marijuana use (p = .04). Researchers should consider using zero-inflated negative binomial regression models when examining youth drug use.

Population-based examination of substance use disorders and treatment use among US young adults in the National Survey on Drug Use and Health, 2011-2019

Background

Compared with adults of other age groups, young adults are more likely to have substance use disorders (SUDs) but less likely to receive treatment. Untreated SUDs can lead to lethal consequences, particularly deaths related to drug overdose.

Objectives

This study aimed to examine trends and sociodemographic differences in the prevalence and treatment use of SUDs among US young adults aged 18 to 25 in the National Survey on Drug Use and Health 2011-2019.

Methods

Bivariable logistic regression analyses were conducted to examine annual changes in the prevalence and treatment use of SUDs, and multivariable logistic regression was used to examine sociodemographic differences in SUD prevalence and treatment use in the pooled sample of young adults from 2011 to 2019.

Results

From 2011 to 2019, the overall SUD prevalence increased significantly from 5.4% to 6.2%. Cannabis use disorder was the most common SUD annually. Groups with lower prevalence of SUDs included females, young adults aged 22-25, and Hispanic, Black, and Asian participants. Across the survey years, the prevalence of treatment use fluctuated insignificantly between 10.9% and 16.9% among young adults with SUDs, and most young adults received SUD treatment in self-help groups and residential and outpatient rehabilitation facilities. Compared to White participants, treatment use was lower in Hispanic, Black, Asian participants, as well as young adults of two or more races. Young adults covered by Medicaid/CHIP were more likely to use treatment.

Conclusions

This study revealed an alarming level of unmet treatment need and significant disparities in treatment use among young adults with SUDs. To reduce barriers to treatment utilization, more coordinated efforts that leverage policy and structural changes alongside innovations to engage young adults with SUD care are needed.

Adolescent simultaneous use of alcohol and marijuana by trends in cigarette and nicotine vaping from 2000 to 2020

BACKGROUND

Simultaneous alcohol and marijuana (SAM) use is associated with adverse consequences for youth. While SAM use is overall declining among youth, prior studies indicate increasing marijuana use among US adolescents who ever used cigarettes, suggesting possible moderation of the alcohol-marijuana relationship by cigarette use.

METHODS

We included 43,845 12-th grade students participating in Monitoring the Future data (2000-2020). A 5-level alcohol/marijuana measure was used, including past-year SAM, alcohol-only, marijuana-only, non-simultaneous alcohol and marijuana, or no use. Multinomial logistic regressions estimated associations between time periods (categorized based on sample size: 2000-2005, 2006-2009, 2010-2014, 2015-2020) and the 5-level alcohol/marijuana measure. Models adjusted for sex, race, parental education and survey mode and included interactions of time periods and lifetime cigarette or vaped nicotine use.

RESULTS

While overall SAM among 12th graders decreased from 23.65% to 18.31% between 2000 and 2020, SAM increased among students who never used cigarettes or vaped nicotine (from 5.42% to 7.03%). Among students who ever used cigarettes or vaped nicotine, SAM increased from 39.2% in 2000-2005-44.1% in 2010-2014 then declined to 37.8% in 2015-2020. Adjusted models controlling for demographics indicated that among students with no lifetime cigarette or vaped nicotine use, students in 2015-2020 had 1.40 (95% C.I. 1.15-1.71) times the odds of SAM, and 5.43 (95% C.I. 3.63-8.12) times the odds of marijuana-only (i.e., no alcohol use) compared to students who used neither in 2000-2005. Alcohol-only declined over time in both students who ever and never used cigarettes or nicotine vape products.

CONCLUSION

Paradoxically, while SAM declined in the overall adolescent US population, the prevalence of SAM increased among students who have never smoked cigarettes or vaped nicotine. This effect arises because of a substantial decline in the prevalence of cigarette smoking; smoking is a risk factor for SAM, and fewer students smoke. Increases in vaping are offsetting these changes, however. Preventing adolescent use of cigarettes and nicotine vaped products could have extended benefits for other substance use, including SAM.

Recreational cannabis legislation and binge drinking in U.S. adolescents and adults

BACKGROUND

Recreational cannabis laws (RCLs) may have spillover effects on binge drinking. Our aims were to investigate binge drinking time trends and the association between RCLs and changes in binge drinking in the United States (U.S.).

METHODS

We used restricted National Survey on Drug Use and Health data (2008-2019). We examined trends in the prevalence of past-month binge drinking by age groups (12-20, 21-30, 31-40, 41-50, 51+). Then, we compared model-based prevalences of past-month binge drinking before and after RCL by age group, using multi-level logistic regression with state random intercepts, an RCL by age group interaction term, and controlling for state alcohol policies.

RESULTS

Binge drinking declined overall from 2008 to 2019 among people aged 12-20 (17.54% to 11.08%), and those aged 21-30 (43.66% to 40.22%). However, binge drinking increased among people aged 31+ (ages 31-40: 28.11% to 33.34%, ages 41-50: 25.48% to 28.32%, ages 51+: 13.28% to 16.75%). When investigating model-based prevalences after versus before RCL, binge drinking decreased among people aged 12-20 (prevalence difference=-4.8%; adjusted odds ratio (aOR)=0.77, [95% confidence interval (CI) 0.70-0.85]), and increased among participants aged 31-40 (+1.7%; 1.09[1.01-1.26]), 41-50 (+2.5; 1.15[1.05-1.26]) and 51+ (+1.8%; 1.17[1.06-1.30]). No RCL-related changes were noted in respondents ages 21-30.

CONCLUSIONS

Implementation of RCLs was associated with increased past-month binge drinking in adults aged 31+ and decreased past-month binge drinking in those aged < 21. As the cannabis legislative landscape continues to change in the U.S., efforts to minimize harms related to binge drinking are critical.

The acute effects of cannabis with and without cannabidiol in adults and adolescents: A randomised, double-blind, placebo-controlled, crossover experiment

BACKGROUND AND AIMS

Long-term harms of cannabis may be exacerbated in adolescence, but little is known about the acute effects of cannabis in adolescents. We aimed to (i) compare the acute effects of cannabis in adolescent and adult cannabis users and (ii) determine if cannabidiol (CBD) acutely modulates the effects of delta-9-tetrahydocannabinol (THC).

DESIGN

Randomised, double-blind, placebo-controlled, crossover experiment. The experiment was registered on ClinicalTrials.gov (NCT04851392).

SETTING

Laboratory in London, United Kingdom.

PARTICIPANTS

Twenty-four adolescents (12 women, 16- to 17-year-olds) and 24 adults (12 women, 26- to 29-year-olds) who used cannabis 0.5-3 days/week and were matched on cannabis use frequency (mean = 1.5 days/week).

INTERVENTION

We administered three weight-adjusted vaporised cannabis flower preparations: 'THC' (8 mg THC for 75 kg person); 'THC + CBD' (8 mg THC and 24 mg CBD for 75 kg person); and 'PLA' (matched placebo).

MEASUREMENTS

Primary outcomes were (i) subjective 'feel drug effect'; (ii) verbal episodic memory (delayed prose recall); and (iii) psychotomimetic effect (Psychotomimetic States Inventory).

FINDINGS

Compared with 'PLA', 'THC' and 'THC + CBD' significantly (P < 0.001) increased 'feel drug effect' (mean difference [MD] = 6.3, 95% CI = 5.3-7.2; MD = 6.8, 95% CI = 6.0-7.7), impaired verbal episodic memory (MD = -2.7, 95% CI = -4.1 to -1.4; MD = -2.9, 95% CI = -4.1 to -1.7) and increased psychotomimetic effects (MD = 7.8, 95% CI = 2.8-12.7; MD = 10.8, 95% CI = 6.2-15.4). There was no evidence that adolescents differed from adults in their responses to cannabis (interaction P ≥ 0.4). Bayesian analyses supported equivalent effects of cannabis in adolescents and adults (Bayes factor [BF01 ] >3). There was no evidence that CBD significantly modulated the acute effects of THC.

CONCLUSIONS

Adolescent cannabis users are neither more resilient nor more vulnerable than adult cannabis users to the acute psychotomimetic, verbal memory-impairing or subjective effects of cannabis. Furthermore, in adolescents and adults, vaporised cannabidiol does not mitigate the acute harms caused by delta-9-tetrahydocannabinol.

Risk Factors for Adolescent Cannabis Use in a State With Legal Recreational Cannabis: The Role of Parents, Siblings, and Friends

PURPOSE

Cannabis use during adolescence can have harmful consequences, including poor educational outcomes, neurocognitive defects, and an increased risk of addiction to other drugs, such as tobacco, alcohol, and opioids. Perceived family and social network cannabis use is a risk factor for use among adolescents. It is not currently known whether there is an association between perceived family/social network cannabis use and adolescent cannabis use in the context of legalization. The purpose of this study was to examine associations between adolescent perceptions of parent, sibling, and best friend medical and/or recreational cannabis use and adolescents' own use and whether the association changed pre-legalization and post-legalization in Massachusetts.

METHODS

We analyzed responses from surveys administered to students at 2 high schools in Massachusetts before legalization in 2016 (wave 1) and after legalization but before the start of regulated retail cannabis sales in 2018 (wave 2). We used χ2 tests and multiple logistic regression to examine associations between adolescent perception of parent, sibling, and best friend use and adolescent past 30-day cannabis use before and after legalization.

FINDINGS

In this sample, no statistically significant differences were found in the prevalence of past 30-day cannabis use before and after legalization among adolescents. There was an increase in the proportion of adolescents who reported any perceived parent cannabis use from before to after legalization (18% before legalization to 24% after legalization; P = 0.018). Perceived parent, sibling, and best friend medical and recreational cannabis use were all associated with an increased odds of adolescent use, with the highest increase in odds found for perceived best friend use (adjusted odds ratio, 17.2; 95% CI, 12.4-24.0).

IMPLICATIONS

Adolescent perceptions of their parents as cannabis users increased after legalization, even before state-regulated retails sales began. Parent, sibling, and best friend cannabis use is each independently associated with increased odds of adolescent's own use. These findings from 1 Massachusetts district should be explored in larger and more representative populations and motivate additional attention to interventions that consider family and friend influences when seeking to address adolescent cannabis use.

Cannabis Recreational Legalization and Prevalence of Simultaneous Cannabis and Alcohol Use in the United States

BACKGROUND

Simultaneous cannabis/alcohol use, using both substances within a short time interval so that their effects overlap, has a greater risk of potential negative consequences than single-substance use and is more common in younger age. Relationships between recreational cannabis laws (RCLs) and changes in simultaneous cannabis/alcohol use prevalence remain untested.

OBJECTIVE

To examine trends in simultaneous cannabis/alcohol use from 2008 to 2019, and investigate associations between implementation of RCLs (i.e., presence of active legal dispensaries or legal home cultivation) and simultaneous cannabis/alcohol use in the United States (U.S.).

DESIGN

Repeated cross-sectional samples from the 2008-2019 U.S. National Survey on Drug Use and Health (NSDUH).

PARTICIPANTS

Respondents (51% female) aged 12 and older.

INTERVENTIONS

Changes in simultaneous cannabis/alcohol use before and after RCL implementation (controlling for medical cannabis law implementation) were compared in different age groups (12-20, 21-30, 31-40, 41-50, 51+), using adjusted multi-level logistic regression with state random intercepts and an RCL/age group interaction.

MEASUREMENTS

Self-reported simultaneous cannabis/alcohol use.

RESULTS

From 2008 to 2019, the overall prevalence of simultaneous cannabis/alcohol use declined among those aged 12-20 but increased in adults aged 21+. Model-based simultaneous cannabis/alcohol use prevalence increased after RCL implementation among respondents aged 21-30 years (+1.2%; aOR= 1.15 [95%CI = 1.04-1.27]), 31-40 years (+1.0; 1.15 [1.04-1.27]), and 41-50 years (+1.75; 1.63 [1.34-1.98]), but not in individuals aged <21 or 51+ years.

CONCLUSIONS

Implementation of recreational cannabis policies resulted in increased simultaneous use of cannabis and alcohol, supporting the complementarity hypothesis, but only among adults aged 21+. Efforts to minimize harms related to simultaneous cannabis/alcohol use are critical, especially in states with RCLs. Future studies should investigate cultural norms, perceived harm, and motives related to simultaneous use.

Cannabis Toxicity in Children and Adolescents

The legalization of recreational and medical cannabis has increased the availability and potency of cannabis products in homes and communities. Although state laws regarding legalization and commercial sale often encompass adult use only, pediatric toxicity from unintentional exposures to cannabis edibles and adolescent harm from chronic use are increasing in states and countries that have relaxed laws on use. Unintentional edible ingestions are shown to increase in regions that legalize and commercialize cannabis products at the retail level. Long-term effects on teenagers regarding psychiatric changes as well as acute gastrointestinal effects from hyperemesis syndrome are well documented in the medical literature. This article provides clinical information on the presentation, evaluation, and management of adverse effects from pediatric and adolescent teen exposures to cannabis seen in acute care and emergent settings. [Pediatr Ann. 2023;52(5):e181-e186.].

Study design to evaluate a web-intervention to prevent alcohol and cannabis-impaired driving and use among adolescents in driver education

BACKGROUND

Alcohol and cannabis are the most commonly used substances among adolescents in the U.S. The consequences related to using both substances together are significantly higher relative to use of either substance alone. Teens' propensity to engage in risky driving behaviors (e.g., speeding, rapid lane changes, and texting) and their relative inexperience with the timing and duration of cannabis' effects puts them at heightened risk for experiencing harms related to driving under the influence. Use of alcohol and cannabis peak at age 16, the legal age teens may apply for a provisional driver's license in some states. Targeting novice teen drivers prior to licensure is thus an ideal time for prevention efforts focused on reducing alcohol and/or cannabis initiation, use, and impaired driving.

METHODS

The current study proposes to evaluate the efficacy of webCHAT among 15.5 to 17-year-old adolescents (n = 150) recruited at driver education programs. WebCHAT is a single session online intervention that aims to prevent alcohol and cannabis use and risky driving behaviors. We will recruit adolescents enrolled in driver education programs, and stratify based on whether they used cannabis and/or alcohol in the past 3 months (60% screening negative and 40% screening positive). All participants will receive usual driver education and half will also receive webCHAT. We will test whether webCHAT in addition to usual driver education reduces alcohol and/or cannabis initiation or use and reduces risky driving attitudes and behaviors (intent to drive after drinking/using, riding as a passenger with someone who drank/used) compared to teens in usual driver education over a 6-month period. We will also explore whether variables such as beliefs and perceived norms serve as explanatory mechanisms for our outcomes.

DISCUSSION

The study has the potential to promote public welfare by decreasing adolescent initiation and use of cannabis and alcohol and reducing risky driving behaviors that can have substantial monetary, personal, and social costs. The study recruits adolescents who are at risk for substance use as well as those who are not and it is delivered remotely during a teachable moment when adolescents receive driver education. Trial registration This study was registered with ClinicalTrials.gov on July 13, 2021 (NCT04959461). https://clinicaltrials.gov/ct2/show/NCT04959461.

THC and CBD: Villain versus Hero? Insights into Adolescent Exposure

Cannabis is the most used drug of abuse worldwide. It is well established that the most abundant phytocannabinoids in this plant are Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). These two compounds have remarkably similar chemical structures yet vastly different effects in the brain. By binding to the same receptors, THC is psychoactive, while CBD has anxiolytic and antipsychotic properties. Lately, a variety of hemp-based products, including CBD and THC, have become widely available in the food and health industry, and medical and recreational use of cannabis has been legalized in many states/countries. As a result, people, including youths, are consuming CBD because it is considered “safe”. An extensive literature exists evaluating the harmful effects of THC in both adults and adolescents, but little is known about the long-term effects of CBD exposure, especially in adolescence. The aim of this review is to collect preclinical and clinical evidence about the effects of cannabidiol.

Associations of alternative cannabis product use and poly-use with subsequent illicit drug use initiation during adolescence

RATIONALE

Specific cannabis products may differentially increase risk of initiating non-cannabis illicit drug use during adolescence.

OBJECTIVE

To determine whether ever- and poly-use of smoked, vaporized, edible, concentrate, or blunt cannabis products are associated with subsequent initiation of non-cannabis illicit drug use.

METHODS

High school students from Los Angeles completed in-classroom surveys. The analytic sample (N = 2163; 53.9% female; 43.5% Hispanic/Latino; baseline M age = 17.1 years) included students who reported never using illicit drugs at baseline (spring, 11th grade) and provided data at follow-up (fall and spring, 12th grade). Logistic regression models assessed associations between use of smoked, vaporized, edible, concentrate, and blunt cannabis at baseline (yes/no for each product) and any non-cannabis illicit drug use initiation-including cocaine, methamphetamine, psychedelics, ecstasy, heroin, prescription opioids, or benzodiazepines-at follow-up.

RESULTS

Among those who never used non-cannabis illicit drugs at baseline, ever cannabis use varied by cannabis product (smoked = 25.8%, edible = 17.5%, vaporized = 8.4%, concentrates = 3.9%, and blunts = 18.2%) and patterns of use (single product use = 8.2% and poly-product use = 21.8%). After adjustment for baseline covariates, odds of illicit drug use at follow-up were largest for baseline ever users of concentrates (aOR [95% CI] = 5.74[3.16-10.43]), followed by vaporized (aOR [95% CI] = 3.11 [2.41-4.01]), edibles (aOR [95% CI] = 3.43 [2.32-5.08]), blunts (aOR [95% CI] = 2.66[1.60-4.41]), and smoked (aOR [95% CI] = 2.57 [1.64-4.02]) cannabis. Ever use of a single product (aOR [95% CI] = 2.34 [1.26-4.34]) or 2 + products (aOR [95% CI] = 3.82 [2.73-5.35]) were also associated with greater odds of illicit drug initiation.

CONCLUSIONS

For each of five different cannabis products, cannabis use was associated with greater odds of subsequent illicit drug use initiation, especially for cannabis concentrate and poly-product use.

Associations between early childhood adversity and behavioral, substance use, and academic outcomes in childhood through adolescence in a U.S. longitudinal cohort

BACKGROUND

Childhood adversity is strongly associated with adolescent substance use, but few epidemiologic studies have investigated early childhood adversity (ECA) before age 5. This study investigated pathways by which ECA is associated with adolescent alcohol and cannabis use and high school completion through childhood behavioral and academic mediators and their reciprocal effects.

METHODS

Data were from the National Longitudinal Survey of Youth 1979-Child/Young Adult Cohort which surveyed children born 1984-1999 and followed through 2016 (n = 5521). Outcomes included alcohol and cannabis use frequency at ages 15-18, and high school completion by age 19. ECA at ages 0-4 was a cumulative score of maternal heavy drinking/drug use, low emotional support, low cognitive stimulation, and household poverty. Multilevel path models were conducted with ECA, childhood mediators (behavioral (externalizing and internalizing problems) and academics (reading and math scores), accounting for demographics and confounders.

RESULTS

ECA was indirectly associated with adolescent cannabis frequency through mediators of externalizing/internalizing problems, low academics, and early cannabis onset before age 14. ECA was also indirectly associated with alcohol frequency via the same mediators, but not early alcohol onset. Greater behavioral problems elevated substance use risk; whereas, low academics reduced risk. Reciprocal effects were evident between childhood behavioral problems and cannabis frequency to high school completion.

CONCLUSION

Adversity from birth to age 4 is associated with childhood behavioral problems and lower academics, which increased adolescent alcohol and cannabis use and lowered high school completion. Early childhood interventions with parents and preschools/daycare may reduce early onset and adolescent substance use.

Recreational cannabis legalization alters associations among cannabis use, perception of risk, and cannabis use disorder treatment for adolescents and young adults

OBJECTIVE

Understanding how recreational cannabis legalization may impact cannabis use disorder (CUD) among adolescents and young adults is key to developing an appropriate public health response. This research investigates whether associations among adolescent and young adult perception of risk of harm from cannabis use, prevalence of past-month cannabis use, and rate of CUD treatment admissions changed following recreational cannabis legalization in the US, 2008-2019.

METHODS

Data from the NSDUH and TEDS-A datasets are employed in difference-in-differences models of the effect of recreational legalization on perception of risk, cannabis use prevalence, and CUD treatment admissions. Moderated models test whether associations among variables changed following recreational legalization.

RESULTS

Following recreational legalization: 1) adolescent and young adult past-month cannabis use prevalence increased; 2) among both adolescents and young adults, the association of lower perception of risk of harm with higher cannabis use prevalence was strengthened; 3) among adolescents, the association of higher cannabis use prevalence with higher CUD treatment admissions was suppressed; and 4) among young adults, an association of higher cannabis use prevalence with lower CUD treatment admissions emerged.

CONCLUSIONS

Recreational legalization is likely to increase cannabis use among adolescents and young adults who perceive cannabis as less harmful, while at the same time reduce rates of CUD treatment utilization. These trends portend an increase in unmet need for CUD treatment for age groups particularly vulnerable to the development and negative consequences of CUD.

Generational shifts in attitudes and beliefs about alcohol: An age-period-cohort approach

INTRODUCTION AND AIMS

Population level alcohol consumption has declined markedly in Australia in the past two decades, with distinct generational patterns. The underlying reason for this shift remains unclear and there has been little work assessing how attitudes and beliefs about alcohol have shifted in population sub-groups.

DESIGN AND METHODS

Using seven waves of survey data spanning 19 years (2001-2019, n = 166,093 respondents aged 14 +), we assess age, time-period and birth cohort effects on trends in four measures of alcohol attitudes (disapproval of regular alcohol use, perceptions of safe drinking levels for men and women and perception that alcohol causes the most deaths of any drug in Australia).

RESULTS

There were steady increases in period effects for perceived safe drinking levels (especially for men) and belief that alcohol causes the most deaths. Disapproval of regular use has been stable at the population level, but there are marked cohort differences, with early and recent cohorts more likely than others to disapprove of regular alcohol use.

DISCUSSIONS AND CONCLUSIONS

These findings point to a broad lowering of perceived safe levels of drinking across the population alongside a sharp increase in disapproval of drinking for recent cohorts, potentially contributing to the reductions in drinking that have been reported in these cohorts.

Short-Term Effects of Recreational Cannabis Legalization on Youth Cannabis Initiation

PURPOSE

As recreational cannabis is legalized, it is critical to know the impacts of legalization on youth cannabis use. Existing research generates conflicting results and does not shed light on channels of effects. This study investigates the impacts of legalization on youth cannabis initiation and overall cannabis use prevalence.

METHODS

We used Interrupted Time Series design and data from nationally-representative repeated cross-sectional Canadian surveys spanning 16 years. The primary outcomes were cannabis initiation rates and cannabis use prevalence among youths. The secondary outcomes were self-reported age of first cannabis use, ease of cannabis access, and perception of cannabis harm among youths.

RESULTS

After legalization, cannabis initiation rate among youths was 2.7 percentage points (95% confidence interval: 1.7-3.7; p < .01) or 69% higher, although there was no significant increase in the overall prevalence of cannabis use. Furthermore, there was a 4-month delay in the average age of first cannabis use among youths aged 17-18 years (95% confidence interval: 2.6-5.5 months; p < .01). The legalization was associated with greater perception of cannabis harm but also easier access to cannabis.

DISCUSSION

The impacts of legalization on youth cannabis use after 1 year are mixed. Although we observed an increase in cannabis initiation among youths who had never used cannabis, there was no change in the overall prevalence of cannabis use, implying a possible offsetting increase in cannabis cessation among existing users. To achieve legalization's goal of reducing youth cannabis use, policy measures are needed to curb youth cannabis access and initiation.

Abrupt peaks in perceived risk of occasional drug use after changing the question order in a repeated self-administered survey

Background

Question-order changes in repeated surveys can distort comparisons. We want to describe the evolution of drug risk perceptions among Spanish adolescents and assessing whether the 2006 peaks in perceived risk of occasional drug use can be explained by question-order changes.

Methods

The subjects were secondary students from a biennial national survey during 2000-2012. A one-off intervention was applied in 2006, replacing the two-adjacent items on perceived risk of occasional and regular use of each drug by non-adjacent items. Annual prevalence of high-risk perception were obtained for occasional and regular use of cannabis, heroin, cocaine and ecstasy. Subsequently, the 2006 percent level change (PC) in such were estimated prevalence using segmented Poisson regression, adjusting for various student and parent covariates.

Results

The 2006 PC in prevalence of high-risk perception of occasional drug use ranged from +63% (heroin) to +83% (ecstasy). These PCs were very high in all considered subgroups. However, the 2006 PC in prevalence of high-risk perception of regular drug use ranged from 1% (heroin) to 12% (cannabis). The evolution of preventive interventions does not suggest alternative causal hypotheses for 2006 peaks other than question-order changes.

Conclusion

Within the cognitive heuristics framework, the 2006 spikes in perceived risk of occasional drug use were most likely due to a release of the anchor exerted by perceived risk of regular drug use over that of occasional use triggered by 2006 question-order changes. In repeated surveys it is inexcusable to pre-test the effect of any change in questionnaire format.

A Review of the Effects of Adolescent Cannabis Use on Physical Health

The current review highlights the available research related to cannabis and indicators of physical health in a variety of domains. Various studies have found associations between cannabis use with pulmonary, cardiovascular, gastrointestinal, and endocrine function as well as body mass index and sleep. At this time, more research is needed to understand the influence of cannabis use on physical health, particularly among adolescent samples.

In harm's way: Do college students' beliefs about cannabis put them at risk for use?

Objective: This study describes beliefs held by college students about cannabis use and examines the association between three specific cannabis beliefs and likelihood of use. Participants: 3,720 undergraduate students ages 18 to 25 attending ten colleges in one state. Methods: Data were gathered via online survey. Results: The majority (80%) of the sample was unsure or believed that cannabis was an effective way to reduce stress; 67% were unsure or believed that cannabis was not related to an increased risk for mental health problems; and 62% were unsure or believed that students who use cannabis are not more academically disengaged. Holding these beliefs, which are not supported by scientific evidence, was associated with a greater likelihood of cannabis use, even after statistically adjusting for covariates. Conclusions: These findings suggest that beliefs unsupported by scientific evidence are widespread among college students. Dispelling misinformation about cannabis might hold promise for reducing use.

Admissions to substance use treatment facilities for cannabis use disorder, 2000-2017: Does legalization matter?

BACKGROUND AND OBJECTIVES

A growing number of US states have legalized marijuana use in the past decade. We examined if marijuana legalization is associated with increased marijuana-related admissions to substance use treatment facilities between 2000 and 2017.

METHODS

Data from the Treatment Episode Data Set-Admissions were used to examine the relationship between marijuana-related admissions among adults aged ≥18 by year and legalization status (i.e., fully legalized, medical use only [partially legalized], and illegal) (N = 35,457,854). Using interaction analyses, we further examined whether certain patient characteristics were associated with residence in states that legalized marijuana use as compared to those in which marijuana remained illegal.

RESULTS

Overall, the proportion of marijuana-related admissions in states with legalization decreased by 2.3% from 31.7% in 2000-2005 to 29.4% in 2012-2017 (odds ratio [OR], 0.90; 95% confidence intervals [CI], 0.89-0.90) with little difference from states where marijuana use remained illegal, in which marijuana use as any reason for admissions decreased by 0.3% from 39.8% in 2000-2005 to 39.5% in 2012-2017 (OR, 0.99; 95% CI, 0.98-0.99). We did not find any striking patient characteristics (e.g., referral by the police) associated with admissions in states that legalized compared to those that had not.

DISCUSSION AND CONCLUSIONS

While earlier studies suggested that marijuana legalization is associated with increased levels of use, emergency department visits, and traffic fatalities, our findings suggest that marijuana legalization did not increase marijuana-related treatment use in the United States.

SCIENTIFIC SIGNIFICANCE

This is the first study to examine the association of marijuana legalization with marijuana-related treatment use.

Cannabidiol use and perceptions in France: a national survey

Background

Cannabidiol (CBD), a safe, non-intoxicating cannabis component, is growing in popularity in Europe and worldwide. However, CBD EU regulation is blurry, and consequent labelling and product quality issues may have implications for public health. There is therefore a need to assess the prevalence and perceived harmfulness of CBD use in EU countries, as well as to characterise CBD users. We aimed to do so in the French population.

Methods

In December 2021, an online survey was conducted in a sample respecting the French adult population structure for key demographic variables. Sociodemographic, behavioural and CBD perception data were collected. Three separate regressions were performed to identify correlates of i) having heard of CBD, ii) using CBD, iii) perceived harmfulness of CBD. A hierarchical classification was also performed to identify profiles of CBD users.

Results

The study sample comprised 1969 adults, of whom 69.2% had heard of CBD and 10.1% used it. Less than half (46.8%) of the former considered it harmful. Having heard of CBD was associated with younger age, being born in France, tobacco use, and cannabis use. CBD use was associated with younger age, tobacco use, cannabis use, poor self-reported general health status, and positive perception of alternative medicines. Cluster analysis revealed four different CBD user profiles based on socio-demographics and behavioural characteristics.

Conclusion

Ten percent of the adults in this French study used CBD, and several user profiles emerged. Our results indirectly advocate clearer European CBD regulations to ensure safe and high-quality products.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14057-0.

A Longitudinal Study of E-Cigarette, Cigarette, and Marijuana Use Sequence in Youth

Objective

There is evidence linking youth use of electronic (e-) cigarettes to subsequent cigarette and marijuana use, raising public health concerns. We examined the sequence of use of e-cigarettes, conventional cigarettes, and marijuana in a longitudinal sample of adolescents, to determine if use of e-cigarettes often preceded use of other substances.

Methods

We collected self-reports from 1123 Oregon adolescents (52% female; 37% Hispanic) longitudinally from 8^th to 11^th grade (8 total surveys) regarding their lifetime (ever use) and current use (last 30 days) of e-cigarettes, cigarettes, and marijuana. If applicable, students also reported the delivery method of their current marijuana use.

Results

Almost 10% of adolescents reported using e-cigarettes prior to use of cigarettes or marijuana, and the majority of these youth initiated use of marijuana, cigarettes, or both by 11^th grade. More youth transitioned from e-cigarette use to marijuana use then from e-cigarettes to use of conventional cigarettes. Participants who were co-using e-cigarettes and marijuana in 11^th grade had an increased likelihood of consuming marijuana via vaping, dabbing, and edibles, compared to those who were only using marijuana.

Discussion

E-cigarettes were often the first substance used in this longitudinal sample, and more of these youth subsequently used marijuana compared to cigarettes. While research has focused on the progression from e-cigarettes to cigarettes in youth, these findings indicate that more attention should be focused on the subsequent initiation of marijuana.

Motives, Frequency, and Consequences of Cannabis Use Among College Students

We investigated profiles of cannabis use motives among current cannabis-consuming college students. Then we assessed profile differences in demographic characteristics, social contexts of use, regulatory environment, alcohol use, negative affect, negative consequences, and cannabis use. Participants ( N = 1, 213) were from three universities in states with different cannabis legislation. Six profiles emerged: Low Motives, Low to Moderate Enhance, High Enhance, High Enhance & Social + Moderate Expand, High Enhance & Cope, and High Motives. Profiles differed in social contexts of use, sex, alcohol use, negative affect, and regulatory environment. Profiles endorsing high and multiple motives had higher cannabis use and negative consequences, relative to profiles with low or fewer motives. Profiles characterized by high avoidance motives (i.e., coping) had the highest cannabis use and consequences. Interventions targeting types and intensity of motives for cannabis-use may help reduce use and related consequences among college students who use cannabis.

Marijuana Use Is Associated With Suicidal Ideation and Behavior Among US Adolescents at Rates Similar to Tobacco and Alcohol

This study used data from the National Youth Risk Behavior Survey to examine the association between adolescent marijuana, tobacco, and alcohol use and suicidal ideation and attempts over a period of six years (2011-2017), as attitudes and laws became more permissive of marijuana use. We used logistic regression to control for possible confounders, estimate marginal prevalence ratios (PR's), and assess changes over time. Marijuana was more strongly associated with suicide attempts than ideation, and more frequent use was associated with significantly greater risk. The effect has not changed substantively since 2011, despite changing attitudes toward marijuana. Marijuana is broadly comparable to other substances: results for tobacco were similar, though frequent alcohol use had a significantly stronger association than other substances.

Systematic review of structural and functional neuroimaging studies of cannabis use in adolescence and emerging adulthood: evidence from 90 studies and 9441 participants

Cannabis use peaks in adolescence, and adolescents may be more vulnerable to the neural effects of cannabis and cannabis-related harms due to ongoing brain development during this period. In light of ongoing cannabis policy changes, increased availability, reduced perceptions of harm, heightened interest in medicinal applications of cannabis, and drastic increases in cannabis potency, it is essential to establish an understanding of cannabis effects on the developing adolescent brain. This systematic review aims to: (1) synthesize extant literature on functional and structural neural alterations associated with cannabis use during adolescence and emerging adulthood; (2) identify gaps in the literature that critically impede our ability to accurately assess the effect of cannabis on adolescent brain function and development; and (3) provide recommendations for future research to bridge these gaps and elucidate the mechanisms underlying cannabis-related harms in adolescence and emerging adulthood, with the long-term goal of facilitating the development of improved prevention, early intervention, and treatment approaches targeting adolescent cannabis users (CU). Based on a systematic search of Medline and PsycInfo and other non-systematic sources, we identified 90 studies including 9441 adolescents and emerging adults (n = 3924 CU, n = 5517 non-CU), which provide preliminary evidence for functional and structural alterations in frontoparietal, frontolimbic, frontostriatal, and cerebellar regions among adolescent cannabis users. Larger, more rigorous studies are essential to reconcile divergent results, assess potential moderators of cannabis effects on the developing brain, disentangle risk factors for use from consequences of exposure, and elucidate the extent to which cannabis effects are reversible with abstinence. Guidelines for conducting this work are provided.

Perceptions of the health risks of cannabis: estimates from national surveys in Canada and the United States, 2018-2019

Few studies have compared knowledge of the specific health risks of cannabis across jurisdictions. This study aimed to examine perceptions of the health risks of cannabis in Canada and US states with and without legal non-medical cannabis. Cross-sectional data were collected from the 2018 and 2019 International Cannabis Policy Study online surveys. Respondents aged 16-65 (n = 72 459) were recruited from Nielsen panels using non-probability methods. Respondents completed questions on nine health effects of cannabis (including two 'false' control items). Socio-demographic data were collected. Regression models tested differences in outcomes between jurisdictions and by frequency of cannabis use, adjusting for socio-demographic factors. Across jurisdictions, agreement with statements on the health risks of cannabis was highest for questions on driving after cannabis use (66-80%), use during pregnancy/breastfeeding (61-71%) and addiction (51-62%) and lowest for risk of psychosis and schizophrenia (23-37%). Additionally, 12-18% and 6-7% of respondents agreed with the 'false' assertions that cannabis could cure/prevent cancer and cause diabetes, respectively. Health knowledge was highest among Canadian respondents, followed by US states that had legalized non-medical cannabis and lowest in states that had not legalized non-medical cannabis (P < 0.001). Overall, the findings demonstrate a substantial deficit in knowledge of the health risks of cannabis, particularly among frequent consumers.

Gender Differences in Dual Diagnoses Associated with Cannabis Use: A Review

Gender differences in psychiatric disorders and drug use are well known. Cannabis is the most widely used illegal drug among young people. In recent years, its use has been related to the development of psychiatric pathologies; however, few studies have incorporated the gender perspective as of yet. The present work analyses the literature to determine the existence of gender differences in the development of psychotic, depressive and anxious symptoms associated with cannabis use. First, we describe cannabis misuse and its consequences, paying special attention to adolescent subjects. Second, the main gender differences in psychiatric disorders, such as psychosis, depression, anxiety and cannabis use disorders, are enumerated. Subsequently, we discuss the studies that have evaluated gender differences in the association between cannabis use and the appearance of psychotic, depressive and anxious symptoms; moreover, we consider the possible explanations for the identified gender differences. In conclusion, the studies referred to in this review reveal the existence of gender differences in psychiatric symptoms associated with cannabis use, although the direction of such differences is not always clear. Future research is necessary to discern the causal relationship between cannabis use and the development of psychiatric symptoms, as well as the gender differences found.

Societal Costs and Outcomes of Medical and Recreational Marijuana Policies in the United States: A Systematic Review

Significant support exists in the United States for legalization of marijuana/cannabis. As of 2021, 36 states and four territories approved the legalization of medical cannabis via medical marijuana laws (MMLs), and 15 states and District of Columbia (DC) have adopted recreational marijuana laws (RMLs). We performed structured and systematic searches of articles published from 2010 through September 2021. We assess the literature pertaining to adolescent marijuana use; opioid use and opioid-related outcomes; alcohol use; tobacco use; illicit and other drug use; marijuana growing and cultivation; employment, earnings, and other workplace outcomes; academic achievement and performance; criminal activity; perceived harmfulness; traffic and road safety; and suicide and sexual activity. Overall, 113 articles satisfied our inclusion criteria. Except for opioids, studies on use of other substances (illicit drugs, tobacco, and alcohol) were inconclusive. MMLs and RMLs do not generate negative outcomes in the labor market, lead to greater criminal activity, or reduce traffic and road safety.

Medical Cannabis Laws and Adolescent Alcohol Use Initiation

Background

The effects of medical cannabis laws (MCLs) on adolescent alcohol use remains unclear. Previous literature investigates alcohol consumption rather than alcohol initiation among adolescents, and does not examine the effect by sociodemographic characteristics and state-level dispensary status. We used population representative, state-level data to examine the relationship between MCLs and adolescent alcohol initiation.

Methods

Data for this study were derived from the Youth Risk Behavior Survey (YRBS), a nationally representative, cross-sectional school-based survey administered by the Centers for Disease Control (CDC) in odd-numbered years from 1991 to 2015. We used a difference-in-difference model to assess pre and post effects of state MCL enactment on adolescent alcohol use initiation. Logistic regression analyses assessed associations between MCLs and varying ages of initiation. We further stratified our results by race/ethnicity, gender, and dispensary status.

Results

Results from adjusted logistic regression models showed higher odds of initiating alcohol among adolescents in states without MCLs when compared to adolescents in states with MCLs (OR 1.37, [95% CI = 1.29, 1.44]). This effect was consistent across age, race/ethnicity, and gender groups. Reductions in self-report of alcohol initiation were also consistently found in multiple age strata (9-10, 11-12, and 13-14), though this finding did not reach conventional levels of statistical detection in all race/ethnicities.

Conclusions

Our findings support a substitutive effect, suggesting that adolescents in states with MCLs, as opposed to states without MCLs, may substitute cannabis for alcohol. Considering the evolving landscape of medical cannabis laws and the proliferation of state-level legalization laws, further research into the effects of such policies, such as adult-use cannabis laws, is warranted to further elucidate their effects on adolescent substance use.

Age-varying time trends in cannabis- and alcohol-related risk perceptions 2002-2019

BACKGROUND

Alcohol- and cannabis-related risk perceptions are strong predictors of use behavior. Studies suggest that attitudes toward cannabis are becoming increasingly permissive, however studies have yet to comprehensively a) compare time trends in cannabis-related attitudes to those of other commonly used substances, such as alcohol, and b) test whether trends significantly differ by age.

METHOD

Public access data from the National Study on Drug Use and Health from 2002 to 2019 were used (N = 1,005,421). Structural Equation Models tested whether study year (linear trend), was associated with alcohol- and cannabis-related risk perceptions (correlated outcomes), and whether age (adolescence [12-17], emerging adulthood [18-25], adulthood [26-35], middle adulthood [36-49], and older adulthood [50+]) moderated time trends. Sex, race/ethnicity, and use frequency were covaried.

RESULTS

The linear trend of study year was associated with decreased cannabis-related risk perceptions (p < .001). There was also a significant interaction of age by study year for cannabis-related risk perceptions, such that adults, emerging adults, and middle adults had the largest decrease in attitudes over time. For alcohol-related risk perceptions, the linear trend of study year was significantly associated with increased risk perceptions (p = .001), but the interaction of time by age was non-significant; alcohol-related effects were extremely small (b < 0.01).

CONCLUSIONS

Findings suggest that cannabis-related risk perceptions are becoming more permissive with time across ages, but particularly in adults, emerging adults, and middle adults. In contrast, alcohol-related risk perceptions have stayed relatively stable over time, with only negligible increases. Findings underscore the importance of targeting permissive cannabis-related attitudes via prevention efforts.

Adolescent Brain Cognitive Development (ABCD) study Linked External Data (LED): Protocol and practices for geocoding and assignment of environmental data

Our brain is constantly shaped by our immediate environments, and while some effects are transient, some have long-term consequences. Therefore, it is critical to identify which environmental risks have evident and long-term impact on brain development. To expand our understanding of the environmental context of each child, the Adolescent Brain Cognitive Development (ABCD) Study® incorporates the use of geospatial location data to capture a range of individual, neighborhood, and state level data based on the child's residential location in order to elucidate the physical environmental contexts in which today's youth are growing up. We review the major considerations and types of geocoded information incorporated by the Linked External Data Environmental (LED) workgroup to expand on the built and natural environmental constructs in the existing and future ABCD Study data releases. Understanding the environmental context of each youth furthers the consortium's mission to understand factors that may influence individual differences in brain development, providing the opportunity to inform public policy and health organization guidelines for child and adolescent health.

Online Knowledge Translation Program involving Video Games and University Student-Led Tutorials about Cannabis and Psychosis for Black Youth: Mixed Method Feasibility Study (Preprint)

Background

Objective

Methods

Results

Conclusions

Adolescents' Marijuana Use Following Recreational Marijuana Legalization in Alaska and Hawaii

Alaska and Hawaii, the only two noncontiguous states in the United States, have different marijuana policy environments. Alaska enacted recreational marijuana legalization (RML) in 2014, whereas recreational marijuana is still illegal in Hawaii. This study analyzed how RML affects adolescents' marijuana use (MU) by comparing two states. We used data from 2 states (Alaska and Hawaii) from the Youth Risk Behavior Survey, 2009 to 2019 years (N = 35 467). The trends of lifetime MU and current MU were examined. Using difference-in-differences analysis models, this study investigated whether RML increased lifetime and current MU in Alaska compared with Hawaii after adjusting for socioeconomic characteristics. Both lifetime and current MU prevalence among adolescents in Alaska increased after RML, while both rates in Hawaii gradually decreased. The rate of lifetime MU in Alaska was significantly increased after RML (odds ratio [OR] = 1.29) compared with Hawaii. Similarly, the current MU among adolescents in Alaska was significantly increased compared with that in Hawaii (OR = 1.34). Both lifetime and current MU were increased following RML in Alaska, suggesting that RML may affect the increase of MU among adolescents.

Joint perceptions of the risk and availability of Cannabis in the United States, 2002-2018

BACKGROUND

Prior work suggests that perceived risk and perceived availability of cannabis independently affect cannabis use. However, perceived risk likely modifies the effect of perceived availability, and vice versa. This study explored trends in joint perceived risk and availability of cannabis from 2002 to 2018 and the relationship between combined perceptions and cannabis use, frequent use, and cannabis use disorder (CUD).

METHODS

National Surveys on Drug Use and Health data (n = 949,285, ages 12+) were used to create combined categories of perceived risk of weekly cannabis use and perceived cannabis availability. Descriptive analyses compared joint perceived risk/availability trends (pre/post-2015 due to survey redesign) overall and stratified by age, gender, past-year cannabis use, frequent use, and CUD. Regression analysis estimated associations between perceived risk/availability and cannabis outcomes.

RESULTS

From 2002 to 2018, the prevalence of perceiving cannabis as low-risk doubled while perceiving cannabis as available remained unchanged. The proportion of individuals perceiving cannabis as Low-risk/Available increased by 86% from 2002 to 2014 (16.8%-31.2%) and 19% from 2015 to 2018 (30.1%-35.8%) while High-risk/Available and High-risk/Unavailable proportions declined. Differing patterns were observed by age and gender. Compared with individuals perceiving cannabis as High-risk/Unavailable, people in all other perception categories had greater risk of all cannabis outcomes. Results were consistent with additive interaction between perceived risk and availability in their effects on cannabis use.

CONCLUSIONS

Trends and associations with cannabis outcomes differ when considering perceived risk and availability independently versus jointly. Longitudinal studies and cannabis policy evaluations would advance understanding of links between cannabis perceptions and use.

Differences in Opinions About Marijuana Use and Prevalence of Use by State Legalization Status

OBJECTIVE

Beliefs about marijuana use and prevalence of use may be associated with the legalization status of the state of residence. We examined differences in views and rates of use of marijuana among residents in recreationally legal, medically legal, and nonlegal states.

METHODS

We surveyed a nationally representative online panel of US adults (N = 16,280) and stratified results by marijuana legalization status of states. We compared views of residents of recreational states on benefits and risks of marijuana use to residents in other states.

RESULTS

The response rate was 56.3% (n = 9003). Residents in recreationally legal states were more likely to believe marijuana could be beneficial for pain management (73% in recreationally legal states, 67% in medically legal states, 63% in nonlegal states; P value: <0.0001), provide relief from stress, anxiety or depression (52% in recreationally legal states, 47% in medically legal states, 46% in nonlegal states; P value: 0.01), and improve appetite (39% in recreationally legal states, 36% in medically legal states, 33% in nonlegal states; P value: <0.009). In addition, residents in recreational states were significantly more likely to believe that smoking 1 marijuana joint a day is somewhat or much safer than smoking 1 cigarette a day (40.8% in recreationally legal states, 39.1% in medically legal states, and 36.1% in nonlegal states; P value: <0.0001). Residents of recreationally and medically legal states were more likely to believe second-hand marijuana smoke was somewhat or much safer than second-hand tobacco smoke (38.3% in recreationally legal states, 38.3% in medically legal states, and 35.7% in nonlegal states; P value: 0.003). Past-year marijuana use in any form (20% in recreational, 14.1% in medical, 12% in nonlegal) and past-year marijuana use of multiple forms (11.1% in recreational, 6.1% in medical, 4.9% in nonlegal) were highest among residents of recreationally legal states. Overall, prevalence of past-year use of any form of marijuana use was more common among residents of recreationally legal states compared with other states (20.3%, confidence interval [CI] 19.5, 21.1 in recreationally legal states; 15.4%, CI 14.7, 16.2 in medically legal states; 11.9%, CI 11.2, 12.6 in nonlegal states).

CONCLUSIONS

Residents in recreationally legal states were most likely to believe marijuana has benefits, marijuana smoke is safer than tobacco smoke, and have the highest rate of marijuana use. This is cause for concern, given the tide of commercialization, growing number of high-potency cannabis products, and favorable media coverage promoting use for health problems.

A Mapping Literature Review of Medical Cannabis Clinical Outcomes and Quality of Evidence in Approved Conditions in the USA from 2016 to 2019

In 2017, a National Academies of Sciences, Engineering, and Medicine (NASEM) report comprehensively evaluated the body of evidence regarding cannabis health effects through the year 2016. The objectives of this study are to identify and map the most recently (2016-2019) published literature across approved conditions for medical cannabis and to evaluate the quality of identified recent systematic reviews, published following the NASEM report. Following the literature search from 5 databases and consultation with experts, 11 conditions were identified for evidence compilation and evaluation: amyotrophic lateral sclerosis, autism, cancer, chronic noncancer pain, Crohn's disease, epilepsy, glaucoma, human immunodeficiency virus/AIDS, multiple sclerosis (MS), Parkinson's disease, and posttraumatic stress disorder. A total of 198 studies were included after screening for condition-specific relevance and after imposing the following exclusion criteria: preclinical focus, non-English language, abstracts only, editorials/commentary, case studies/series, and non-U.S. study setting. Data extracted from studies included: study design type, outcome definition, intervention definition, sample size, study setting, and reported effect size. Few completed randomized controlled trials (RCTs) were identified. Studies classified as systematic reviews were graded using the Assessing the Methodological Quality of Systematic Reviews-2 tool to evaluate the quality of evidence. Few high-quality systematic reviews were available for most conditions, with the exceptions of MS (9 of 9 graded moderate/high quality; evidence for 2/9 indicating cannabis improved outcomes; evidence for 7/9 indicating cannabis inconclusive), epilepsy (3 of 4 graded moderate/high quality; 3 indicating cannabis improved outcomes; 1 indicating cannabis inconclusive), and chronic noncancer pain (12 of 13 graded moderate/high quality; evidence for 7/13 indicating cannabis improved outcomes; evidence from 6/7 indicating cannabis inconclusive). Among RCTs, we identified few studies of substantial rigor and quality to contribute to the evidence base. However, there are some conditions for which significant evidence suggests that select dosage forms and routes of administration likely have favorable risk-benefit ratios (i.e., epilepsy and chronic noncancer pain). The body of evidence for medical cannabis requires more rigorous evaluation before consideration as a treatment option for many conditions, and evidence necessary to inform policy and treatment guidelines is currently insufficient for many conditions.

Public health impacts to date of the legalisation of medical and recreational cannabis use in the USA

The legality of cannabis use has been changing in a number of jurisdictions around the world. In the U.S., it has been legalised for medicinal and/or recreational uses in 34 jurisdictions and counting. This study leverages the decades-long experience of legalisation in the U.S. to provide an overview of the associated changes in public attitudes, cannabis markets and adverse health effects. We found a broad-based warming of public attitudes toward legalisation, potentially influenced by the increasingly positive portrayal of cannabis in media and declines in cannabis risk perceptions. Potency of cannabis products increased significantly while prices fell sharply. Although adults were less responsive to price changes than adolescents, adults who use cannabis regularly were sensitive to prices, with an estimated 10% price reduction leading to about 2.5% increase in the rate of use. Overall, past-year cannabis use has increased in adults since 2002, and adults over 26 years old who resided in states with medicinal cannabis laws were more likely to have used cannabis in the past 30 days, to have used daily, and to have higher rates of cannabis use disorders than adults who resided in states without legalised medicinal cannabis. Traffic fatalities involving cannabis temporarily increased in some states post-legalisation, and there were more presentations to medical services related to chronic regular cannabis use. There is suggestive evidence that adverse health consequences have increased among people who use cannabis regularly since legalisation. More robust research is needed to determine whether these effects of legalisation are temporary or long-term.

Trends in cannabis use and attitudes toward legalization and use among Australians from 2001-2016: an age-period-cohort analysis

BACKGROUND AND AIMS

Changes in cannabis legalization and availability in Australia necessitate monitoring use and attitudes. We estimated age-period-cohort effects of past-year cannabis use and attitudes toward criminalization and legalization.

DESIGN

Analysis of six waves of the Australian National Drug Strategy Household Survey (NDSHS) every 3 years (2001-2016).

SETTING AND PARTICIPANTS

The study was nationally representative of Australian households using multistage random sampling, totaling 145 168 respondents 18-79 years old. Data were collected using telephone, face-to-face, and drop-and-collect. Sample sizes per analysis varied based on data availability (~107 000-127 000 per model).

MEASUREMENTS

Six waves of data for past-year cannabis use (by sex and education), attitudes toward criminalization and legalization.

FINDINGS

Past-year cannabis use decreased in young adults ages 18-35 from 2001-2016 (25.1%-18.6%) and increased in middle adults ages 36-55 (8.6%-10.1%) and older adults ages 56-79 (0.6%-3.0%). We observed a positive period effect and negative cohort effect for recent cohorts for past-year use (e.g. 1955 cohort had 1.41 (95% CI: [1.11, 1.70]) increased log odds vs. 1998 cohort had -2.86 (95% CI: [-3.17, -2.55]) increased log odds) compared with the mean across years. Results were consistent by sex and varied by education. We observed a negative period effect for criminalization favorability (0.14 (95% CI: [0.003, 0.28]) increased log odds in 2001 vs. -0.31 (95% CI: [-0.45, -0.17]) increased log odds in 2016) and positive cohort effect for recent cohorts. Last, we observed a positive period effect for legalization support (-0.03 (95% CI: [-0.20, 0.14]) increased log odds in 2001 vs. 0.38 (95% CI: [0.22, 0.55]) increased log odds in 2016) and negative cohort effect for recent cohorts.

CONCLUSION

Cannabis use appears to be increasing in Australia among adults over 35, while decreasing among adolescents and young adults. Legalization support also appears to have been increasing since 2007, signaling discordance between use and attitudes among adolescents and young adults, and potentially predicting increases in use over time.

Driving after marijuana use among U.S. adolescents: Prevalence profiles and related behaviors

OBJECTIVES

The interplay between marijuana legislation, perceptions of risks associated with marijuana use, and marijuana-related risk behaviors is an ever changing and complex issue. Marijuana impaired driving is of concern as legalization continues to expand in the United States. While driving after using marijuana has been shown to be prevalent among adults, little research has examined the behavior in adolescents. The aim of the present study was to examine the prevalence of driving after using marijuana among U.S. adolescents, with an examination of the relationship to age of marijuana initiation and marijuana usage patterns.

METHODS

We analyzed data from the 2017 Youth Risk Behavior Survey, a nationally representative sample of high schools students in the U.S. The sample was current marijuana users, defined as past 30 day use. Driving after using marijuana was the main outcome variable, with analyses examining the association between the outcome and age of initiation and patterns of use. Prevalence ratios were obtained by modeling Poisson regression to examine factors associated with driving under the influence of marijuana.

RESULTS

Nearly half of all marijuana users reported driving after use during the past 30 days, and did not differ between males and females. Prevalence of driving after using marijuana was significantly higher among heavy users (PR = 2.8; 95% CI 2.1-3.6). A higher prevalence of driving after drinking alcohol (PR = 1.7; 95% CI 1.5-1.9) was also found among those who had driven after using marijuana.

CONCLUSIONS

Among adolescent marijuana users, the prevalence of driving after using marijuana was high. Enhanced surveillance, prevention, and control measures are necessary to mitigate the negative impacts of marijuana consumption and related behaviors.

The Need for Marijuana Perceived Risk Interventions Targeting College Students at a Historically Black College and University

The purpose of this pilot study was to test a peer-led Hip-Hop Development Model (HHD) prevention intervention designed to increase the perceived risk from drug use for undergraduate college students attending a Historically Black College and University (HBCU). The HHD model was used to develop prevention messaging to increase the perceived risk from drug use. This study examined the following outcomes of peer-group-based development of public service announcements grounded in HHD: (1) feasibility, (2) acceptability, and (3) potential for immediate posttest and 1-year impact on perceived risk from marijuana use. Findings indicated that the college students were able to produce public service announcements over the course of a semester that could be broadcast to other students on campus. At the 1-year follow-up, perceived risk from marijuana use was significantly higher than at baseline. Perceived risk from marijuana use at baseline was low with 36% of participants who responded moderate or great risk which increased to 63% at immediate and 50% at 1-year posttest. This small pilot study provides insights into what is needed to implement and evaluate youth-targeted marijuana prevention messaging, in a context of rapid increase in the liberalization of adult marijuana use across the United States.