Association of State Recreational Marijuana Laws With Adolescent Marijuana Use

Effects of Cannabis Use on Neurocognition: A Scoping Review of MRI Studies

Cannabis is one of the most commonly utilized recreational drugs. However, increasing evidence from the literature suggests harmful implications on cognition. Thus, the main aim of the current review is to summarize literature findings pertaining to the impact of cannabis on neurocognitive skills, focusing on the imaging biomarkers provided by MRI. Two reviewers navigated the literature independently using four main search engines including PubMed and Cochrane. Articles were first evaluated through their title and abstract, followed by full-text assessment. Study characteristics and findings were extracted, and the studies' quality was appraised. 47 articles were included. The majority of the studies were of a case-control design (66%), and the most studied neurocognitive skill was memory (40.4%). With task-based fMRI being the most commonly utilized MRI technique, findings have shown significantly varying decreased and increased neuronal activity within brain regions associated with the cognitive tasks performed. Results suggest that cannabis users are significantly suffering from cognitive deficits. The major significance of this review is attributed to highlighting the role of MRI. Future research needs to delve more into validating the negative effects of cannabis, to enable stakeholders to take action to limit cannabis usage, to foster public health and wellbeing.

Increasing lifetime and past 30-day marijuana use among middle school students regardless of recreational marijuana sales

PURPOSE

This study investigated whether adult use marijuana sales were associated with changes in lifetime and past 30-day (P30D) marijuana use among middle school students in Nevada (NV), which had adult-use marijuana sales during the study period, compared to New Mexico (NM), which did not have adult-use marijuana sales during the study period.

METHODS

Data were drawn from the middle school 2017 and 2019 NV Youth Risk Behavior and NM Youth Risk and Resiliency Surveys. Difference-in-difference analyses compare changes in lifetime and P30D marijuana use in NV (adult-use sales implemented July 2017) vs. NM (no adult-use sales during the study period).

RESULTS

There was no difference in lifetime (aOR 1.11; 95% CI 0.91,1.36) and P30D (aOR 1.17; 95% CI 0.91,1.51) marijuana use by adult-use sales status. The odds of lifetime and P30D marijuana use increased in both states, particularly among students who were female, older, non-White, or attending a Title 1 school.

DISCUSSION

Adult-use sales were not associated with an increase in lifetime or P30D marijuana use. State-level prevention efforts should focus on sub-populations with increasing lifetime and P30D use regardless of adult-use sales status.

Evolving Disparities in Cannabis Use Among Youth by Demographics and Tobacco and Alcohol Use in the U.S.: 2013-2021

INTRODUCTION

This study investigated the prevalence of past 30-day cannabis use among U.S. youth by cigarette use, alcohol use, demographics, and state-of-residence cannabis legal status in 2021 and examined whether changes in cannabis use prevalence were modified by these factors from 2013 to 2021.

METHODS

Data were drawn from the 24 states that collected cannabis use data participating in the Youth Risk Behavior Surveillance System from 2013 to 2021. Logistic regression analyses estimated past 30-day cannabis prevalence in 2021 and produced AORs by current cigarette, alcohol, and state-of-residence cannabis legal status. The same method was used with year as the exposure, adjusting for sex, race, and ethnicity, to assess trends in prevalence from 2013 to 2021.

RESULTS

In 2021, cannabis use was more common among female youth (16.75% vs 13.83% [AOR=1.26, 95% CI=1.16, 1.37]) and non-Hispanic Black and Hispanic youth than among non-Hispanic White youth (17.19%, 16.14% vs 14.60% [AOR=1.25, 95% CI=1.12, 1.39 and AOR=1.16, 95% CI=1.04, 1.29, respectively]). Cannabis use was much more common among youth who reported any past 30-day cigarette or alcohol use (44.90% vs 6.48% [AOR=11.80, 95% CI=10.57, 13.18]). Declines in cannabis use were observed independent of state-level cannabis law from 2013 to 2021, and cannabis use prevalence did not differ significantly by state-of-residence cannabis legal status among the 24 participating states in 2021.

CONCLUSIONS

Public health officials should carefully consider the potential impact of expanding commercialization of cannabis as a wellness product on youth cannabis use, especially with regard to minoritized populations and co-use with tobacco and alcohol. National and state-level public health education on cannabis use and youth-oriented prevention of cannabis uptake are long overdue.

Cannabis use among adolescents and young adults during the COVID-19 pandemic: A systematic review

Background

A systematic review of the literature was performed to summarize cannabis use among adolescents and young adults during the COVID-19 pandemic. Special focus was given to the prevalence of cannabis use during COVID-19, as well as factors that may explain changes in cannabis consumption patterns.

Methods

The protocol of this systematic review was registered. Articles from seven publication databases were searched in January 2022. The inclusion criteria for studies were as follows: 1) published in English; 2) study instruments needed to include items on COVID-19; 3) conducted after January 1st, 2020; 4) published in a peer-reviewed journal, dissertation, or thesis; 5) study population ≤25 years of age; 6) study designs were limited to observational analytical studies; 7) measured cannabis use. This review excluded other reviews, editorials, and conference abstracts that were not available as full text manuscripts. Independent review, risk of bias assessment, and data abstraction were performed by two authors.

Results

Fifteen articles from the United States (n=11) and Canada (n=4) were included in this review. The findings of this review showed that the prevalence of cannabis use during the pandemic among adolescents and young adults were mixed. Some mental health symptoms, including depression and anxiety, were identified as the most commonly reported reasons for increased cannabis use during the pandemic.

Conclusions

This review highlights the inconsistencies in the prevalence of cannabis use among adolescents and young adults during the pandemic. Therapeutic interventions for mental health and continued public health surveillance should be conducted to understand the long-term effects of cannabis use among adolescents and young adults.

Risk-Taking, Social Support, and Belongingness Contribute to the Risk for Cannabis Use Frequency in University Students

Background: Cannabis use and misuse is known to be associated with a variety of negative health, academic, and work-related outcomes; therefore, it is important to study the factors that contribute to or moderate its use. Objectives: The aim of this study was to determine whether risky behavior, belongingness and social support as clustering variables play a role in cannabis use frequency. Method: In a university student sample, participant data on risky behavior, belongingness and social support were used to generate vulnerability profiles through cluster analysis (low vulnerability with low risk, low vulnerability with high belonging, moderate vulnerability, and high vulnerability). Using an analysis of variance, the vulnerability profiles were compared with respect to cannabis use frequency and quantity. Through chi-square tests we assessed whether these profiles are overrepresented in certain demographics. Results: The cluster analysis yielded four groups, which differed in their vulnerability for cannabis use. The most vulnerable cluster group had higher cannabis use frequency relative to the two least vulnerable groups. Low income vs. high income was also associated with high vulnerability group membership. International students were overrepresented in the low vulnerability with high belonging group relative to the low vulnerability with low-risk group. The opposite was observed for domestic students. Conclusions: This research adds to the expanding body of literature on cannabis use and misuse in Canada, which may contribute to public health policy and the prevention and treatment of cannabis addiction by providing new insight on who may be at risk.

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.

Development and initial validation of the cannabis-related psychosis risk literacy scale (CPRL): a multinational psychometric study

BACKGROUND

Public education efforts to address and reduce potential harms from cannabis use in Arab countries are either slow or inexistent, and do not follow the steadily increasing trends of cannabis use in Arab youth. Several decades of research on substance use, it can be suggested that being aware of, and knowing about, psychosis risk related to cannabis can at least limit the consumption of the substance. Motivated by a lack of measures specifically designed to measure literacy about cannabis-related psychosis risk in younger populations, and based on an extensive literature review, we aimed to create and validate a new self-report scale to assess the construct, the Cannabis-related Psychosis Risk Literacy Scale (CPRL), in the Arabic language.

METHOD

A cross-sectional study was carried-out during the period from September 2022 to June 2023, enrolling 1855 university students (mean age of 23.26 ± 4.96, 75.6% females) from three Arab countries (Egypt, Kuwait and Tunisia).

RESULTS

Starting from an initial pool of 20 items, both Exploratory Factor Analysis and Confirmatory Factor Analysis suggested that the remaining 8 items loaded into a single factor. The scale demonstrated good internal consistency, with both McDonald omega and Cronbach's alpha values exceeding 0.7 (omega = 0.85 / alpha = 0.85). The CPRL showed measurement invariance across gender and country at the configural, metric, and scalar levels. Concurrent validity of the CPRL was established by correlations with less favourable attitudes towards cannabis (r = -.14; p <.001). In addition, higher literacy levels were found in students who never used cannabis compared to lifetime users (4.18 ± 1.55 vs. 3.44 ± 1.20, t(1853) = 8.152, p <.001).

CONCLUSION

The newly developed CPRL scale offers a valid and reliable instrument for assessing and better understanding literacy about cannabis-related psychosis risk among Arabic-speaking young adults. We believe that this new scale is suitable as a screening tool of literacy, as an instrument for measuring the effect of public education interventions aimed at promoting cannabis-related psychosis risk literacy among young people, and as a research tool to facilitate future studies on the topic with a wider application.

Systematic Review and Meta-Analysis: Medical and Recreational Cannabis Legalization and Cannabis Use Among Youth in the United States

OBJECTIVE

Dramatic changes in state-level cannabis laws (CL) over the past 25 years have shifted societal beliefs throughout the United States, with unknown implications for youth. In the present study, we conducted an updated systematic review and meta-analysis examining estimated effects of medical cannabis legalization (MCL) and recreational cannabis legalization (RCL) on past-month cannabis use among US youth.

METHOD

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, followed by a subsequent meta-analysis investigating the associations between state-level cannabis laws (ie, MCL vs non-MCL, and RCL vs non-RCL) and past-month cannabis use prevalence among US adolescents and young adults. Supplemental analyses examined age-group effects and design-related factors.

RESULTS

Our search identified 4,604 citations, 34 and 30 of which were included in qualitative and quantitative analyses, respectively. Meta-analysis of MCL studies identified no significant association between MCL and change in past-month youth cannabis use (odds ratio [OR] = 0.981, 95% CI = 0.960, 1.003). Meta-analysis of RCL studies showed significantly increased odds of past-month cannabis use (OR = 1.134, 95% CI = 1.116-1.153). Meta-analysis of more recent studies, however, showed a significantly increased odds of past-month cannabis use among both adolescents and young adults (OR = 1.089, 95% CI = 1.015,1.169, and OR = 1.221, 95% CI = 1.188,1.255, respectively).

CONCLUSION

Cannabis legalization has complex and heterogenous effects on youth use that may differ across law types. Our meta-analytic results showed modest positive effects of RCL on past-month cannabis use (more so in young adults than in adolescents) and minimal effects of MCL on these outcomes in US youth. Given the shift toward recreational legalization, additional focus on RCL effects is warranted.

A systematic review of evidence on integrated management of psychiatric disorders in youth who use cannabis

Given the risks to mental health associated with cannabis use in youth and the increase in cannabis legalization worldwide and in the U.S., there is a need to understand existing evidence-based approaches to integrated management of psychiatric disorders in youth who use cannabis. This systematic review aimed to appraise the current evidence on integrated treatment for adolescents and young adults with common psychiatric disorders who engage in regular cannabis use. A total of 989 studies were screened for inclusion. Study's titles and abstracts were screened and advanced to full text review for further screening by two independent reviewers. Thirty-five full-text articles were reviewed, with five articles ultimately meeting all criteria for inclusion. Five randomized controlled trials examined the effects of therapeutic interventions in youth with common psychiatric disorders who used cannabis, including two studies on depression, one on bipolar disorder, one on anxiety and one on PTSD were reviewed. No studies were considered high in risk of bias. Overall, there is a paucity of research on the treatment of comorbid adolescent mental health disorders and cannabis use, which limits the ability to draw evidence-based treatment recommendations.

Is legalization of recreational cannabis associated with levels of use and cannabis use disorder among youth in the United States? A rapid systematic review

Cannabis legalization policies are rapidly changing in the United States. While there are concerns that recreational legalization will negatively affect young people, previous reviews have not provided clear indication of such effects. The purpose of this rapid systematic review was to examine whether recreational legalization was associated with increases in prevalence of cannabis use and use disorder among adolescents and young adults. PubMed/MEDLINE, Embase, Scopus, PsycInfo, Web of Science, Dissertations & Theses Global, the Trip Database, and OpenGrey were searched from date of inception through Marcy 17, 2022 to retrieve all relevant records. English language and human subject filters were applied. Two reviewers screened abstracts and titles, assessed full text articles, and coded the final included articles. Studies including primarily 10- to 19-year-olds were classified as adolescent, and those between 18 and 26 years as young adult. Our search identified 33 research reports (22 with adolescent samples; 14 young adult). For adolescents, ten studies reported no change in use prevalence associated with legalization, six reported a decrease, and seven reported an increase. Among young adults, most studies (8) showed an increase in at least one prevalence measure, four showed no change, and one showed a decrease. Only two adolescent and one young adult study examined cannabis use disorder, both adolescent studies showed an increase, and the young adult showed no change. The majority of studies had risk of bias. Recreational legalization may be associated with increases in prevalence of cannabis use in young adults while results for adolescents are mixed. Policymakers and practitioners should consider appropriate prevention and treatment options for young people.Trial Registration: PROSPERO #CRD42021276984.

The impact of recreational cannabis legalization on youth: the Colorado experience

Over the past two decades, cannabis policies have liberalized in the United States, culminating in the legalization of recreational cannabis in Colorado and Washington state in 2012. This review will focus on the impact of recreational cannabis legalization in Colorado. While the prevalence of past-year and past-month cannabis use has remained relatively steady among adolescents post-legalization, the prevalence of young adult use has continued to rise. Cannabis products with increased potency have become more prevalent and widely used. There are concerns that the use of products with increased potency will increase risk for cannabis use and comorbid mental health disorders, particularly cannabis-induced psychosis and suicidal behavior, although more research is needed to fully understand the impact of high-potency products. Since the legalization of recreational cannabis, numerous additional public health concerns have emerged: unintentional overdoses requiring acute care visits, electronic vaping-associated lung injury, increased motor vehicle collisions related to cannabis consumption, and higher rates of cannabis use during pregnancy. Lessons learned from the first decade of cannabis legalization emphasize the need for research efforts to provide evidence-based guidelines, inform prevention strategies, and implement selective interventions for at-risk populations including youth, individuals with comorbid mental health disorders, and individuals who are pregnant.

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

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

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.

Salient Beliefs Associated with Unsanctioned Adult Cannabis Use in an Evolving Socio-Political Environment

Background: The changing cannabis legal climate in the United States has been associated with increased prevalence of use, more favorable general attitudes, and cultural norms toward its use among young adults. The purpose of this study was to conceptualize salient beliefs governing illicit cannabis use within a state where medical use is legal and adult use remains illegal. Methods: Following an initial qualitative pilot, a prospective study (baseline and a 30-day follow-up) that utilized an electronic survey design was conducted. Students at a large US university (N = 514) completed a baseline assessment of cannabis use and Theory of Planned Behavior (TPB) constructs, and 169 completed the follow-up assessing actual behavior. Results: Roughly 60% reported illicit cannabis use. Attitude and subjective norms accounted for 57% of the variation in intention for cannabis use in the next 30 days, while intention and perceived behavioral control (PBC) explained 51% of the variation in prospective use. The majority of salient beliefs identified exhibited moderate to strong correlations with intention and behavior among the larger sample. Close friends and partners were identified as important referents, outcome expectations of relaxation, improved social functioning, and more enjoyment, as well as environmental factors, such as proximity to use, safe utilization location, and continued illegality of adult use exhibited strong associations to intention and behavior. Conclusions: The practical utility of the salient belief measures identified herein presents a useful foundation for interventions aimed at reducing illicit cannabis utilization among young adults.

Cannabis and Alcohol Use by U.S. Young Adults, 2008-2019: Changes in Prevalence After Recreational Cannabis Legalization

INTRODUCTION

Young adults' cannabis and alcohol use patterns have changed after state recreational cannabis legalization according to studies based on college samples but not nationally representative samples. Associations between recreational cannabis legalization and changes in cannabis and alcohol use outcomes among young adults were examined, including differences by college enrollment and minor status (ages 18-20 vs 21-23 years).

METHODS

Repeated cross-sectional data (2008-2019) were collected from college-eligible participants aged 18-23 years in the National Survey on Drug Use and Health. Self-reported past-month cannabis use and frequent use (≥20 days) and a proxy for past-year DSM-5 cannabis use disorder were primary outcomes; past-month frequent alcohol use and binge drinking were secondary outcomes. Multilevel logistic regression models quantified changes in outcome prevalence from the study years before to after recreational cannabis legalization, adjusting for secular trends. Analyses were conducted on March 22, 2022.

RESULTS

Prevalence increased from before to after recreational cannabis legalization for past-month cannabis use (from 21% to 25%) and past-year proxy cannabis use disorder (from 11% to 13%); the increases were statistically significant [adjusted odds ratio (95% CI) = 1.20 (1.08-1.32) and 1.14 (1.003-1.30), respectively]. Increases were detected for young adults who were not in college and who were aged 21-23 years. Recreational cannabis legalization impacts were not detected for secondary outcomes.

CONCLUSIONS

Some young adults appear sensitive to state recreational cannabis legalization, including in terms of cannabis use disorder risk. Additional prevention efforts should be directed to young adults who are not in college and timed to occur before age 21 years.

Impact of Cannabis Legalization on Adolescent Cannabis Use

Because of substantial limitations in available national data, such as inconsistencies among surveys and small sample sizes, the increased prevalence of cannabis use among adolescents since recreational legalization has not been directly observed. Nevertheless, both usage frequency and product potency have significantly increased, alongside alternative routes of delivery to smoking, such as vaping cannabis. Moreover, certain populations may be especially vulnerable to the effects of legalization. Regardless of differing state-level cannabis legalization status, the adverse consequences of cannabis on youth have clear negative impacts on mental health, medical symptoms, educational outcomes, and increased risk of addiction to other substances.

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.

Past Cannabis Use, Health-Related Worry, and Beliefs About Perceived Benefits of Cannabis Among American Indians/Alaska Natives

BACKGROUND

Most adults report beliefs that cannabis has at least one benefit (e.g., stress relief, chronic pain management); however, the benefits are not well established. Beliefs about cannabis benefits are associated with the initiation of use, whereas beliefs about the risks of cannabis are protective factors against its use. Little is known about how health-related beliefs impact cannabis use among American Indians/Alaska Natives (AIAN).

PURPOSE

This exploratory study examined beliefs about perceived benefits (i.e., stress relief, pain management) of cannabis, how beliefs vary as a function of use, and associations between health worry and benefits of cannabis among AIAN adults.

METHODS

Participants (n = 182) were on average 41.4 (SD = 16.3) years old, 63.9% female, and identified as AIAN. Participants were asked questions about general demographics, health-related worry and perceptions, and cannabis use. Linear regressions were conducted to examine associations.

RESULTS

Those who used cannabis in the past year were more likely to agree that cannabis relieves stress and less likely to believe that those who use cannabis should be very worried about their health. Participants who agreed that those who use cannabis should be worried about their health were less likely to report beliefs that cannabis relieves stress or helps with chronic pain.

CONCLUSIONS

Our study confirms the role of health-related perceptions and worry about cannabis products with cannabis use among this population that may be at risk for higher cannabis use. Findings may have implications for cannabis policy at the tribal, state, and federal levels and the need for the development of targeted communications about the true health risks of cannabis.

Health, safety, and socioeconomic impacts of cannabis liberalization laws: An evidence and gap map

Background

Globally, cannabis laws and regulations are rapidly changing. Countries are increasingly permitting access to cannabis under various decriminalization, medicalization, and legalization laws. With strong economic, public health, and social justice incentives driving these domestic cannabis policy reforms, liberalization trends are bound to continue. However, despite a large and growing body of interdisciplinary research addressing the policy-relevant health, safety, and socioeconomic consequences of cannabis liberalization, there is a lack of robust primary and systematic research that comprehensively investigates the consequences of these reforms.

Objectives

This evidence and gap map (EGM) summarizes the empirical evidence on cannabis liberalization policies. Primary objectives were to develop a conceptual framework linking cannabis liberalization policies to relevant outcomes, descriptively summarize the empirical evidence, and identify areas of evidence concentration and gaps.

Search Methods

We comprehensively searched for eligible English-language empirical studies published across 23 academic databases and 11 gray literature sources through August 2020. Additions to the pool of potentially eligible studies from supplemental sources were made through November 2020.

Selection Criteria

The conceptual framework for this EGM draws upon a legal epidemiological perspective highlighting the causal effects of law and policy on population-level outcomes. Eligible interventions include policies that create or expand access to a legal or decriminalized supply of cannabis: comprehensive medical cannabis laws (MCLs), limited medical cannabidiol laws (CBDLs), recreational cannabis laws (RCLs), industrial hemp laws (IHLs), and decriminalization of cultivations laws (DCLs). Eligible outcomes include intermediate responses (i.e., attitudes/behaviors and markets/environments) and longer-term consequences (health, safety, and socioeconomic outcomes) of these laws.

Data Collection and Analysis

Both dual screening and dual data extraction were performed with third person deconfliction. Primary studies were appraised using the Maryland Scientific Methods Scale and systematic reviews were assessed using AMSTAR 2.

Main Results

The EGM includes 447 studies, comprising 438 primary studies and nine systematic reviews. Most research derives from the United States, with little research from other countries. By far, most cannabis liberalization research focuses on the effects of MCLs and RCLs. Studies targeting other laws-including CBDLs, IHLs, and DCLs-are relatively rare. Of the 113 distinct outcomes we documented, cannabis use was the single most frequently investigated. More than half these outcomes were addressed by three or fewer studies, highlighting substantial evidence gaps in the literature. The systematic evidence base is relatively small, comprising just seven completed reviews on cannabis use (3), opioid-related harms (3), and alcohol-related outcomes (1). Moreover, we have limited confidence in the reviews, as five were appraised as minimal quality and two as low quality.

Authors’ Conclusions

More primary and systematic research is needed to better understand the effects of cannabis liberalization laws on longer-term-and arguably more salient-health, safety, and socioeconomic outcomes. Since most research concerns MCLs and RCLs, there is a critical need for research on the societal impacts of industrial hemp production, medical CBD products, and decriminalized cannabis cultivation. Future research should also prioritize understanding the heterogeneous effects of these laws given differences in specific provisions and implementation across jurisdictions.

Pre-Post Cannabis Legalization for Adult Use: A Trend Study of Two Cohorts of Young Adult Cannabis Users in Los Angeles

Cannabis was legalized for adult use in California in 2016 for individuals 21 and older. Among 18-20-years-olds, who can possess cannabis legally as medical cannabis patients (MCP) but not as non-patient cannabis users (NPU), the impact of adult use legalization (AUL) on cannabis and other substance use is unknown. Two cohorts of 18-20-year-old cannabis users (MCP and NPU) were surveyed, one in 2014-15 (n = 172 "pre-AUL") and another in 2019-20 (n = 139 "post-AUL"), using similar data collection methods in Los Angeles, California. Logistic and negative binomial regressions estimated cohort and MCP differences for cannabis and other drug use outcomes based on past 90-day use. In both pre- and post-AUL cohorts, MCP were more likely to self-report medical cannabis use (p < .001) while the post-AUL cohort reported greater use of edibles (p < .01), but fewer mean days of alcohol (p < .05) and cigarette (p < .01) use in multivariate models. Notably, frequency of cannabis use (days or hits per day) did not significantly differ between the pre- and post-AUL cohorts, except for greater use of edibles, despite potentially greater access to cannabis.

Impact of cannabis use on brain metabolism using 31P and 1H magnetic resonance spectroscopy

PURPOSE

This prospective cross-sectional study investigated the influence of regular cannabis use on brain metabolism in young cannabis users by using combined proton and phosphorus magnetic resonance spectroscopy.

METHODS

The study was performed in 45 young cannabis users aged 18-30, who had been using cannabis on a regular basis over a period of at least 2 years and in 47 age-matched controls. We acquired 31P MRS data in different brain regions at 3T with a double-resonant 1H/31P head coil, anatomic images, and 1H MRS data with a standard 20-channel 1H head coil. Absolute concentration values of proton metabolites were obtained via calibration from tissue water as an internal reference, whereas a standard solution of 75 mmol/l KH2PO4 was used as an external reference for the calibration of phosphorus signals.

RESULTS

We found an overall but not statistically significant lower concentration level of several proton and phosphorus metabolites in cannabis users compared to non-users. In particular, energy-related phosphates such as adenosine triphosphate (ATP) and inorganic phosphate (Pi) were reduced in all regions under investigation. Phosphocreatine (PCr) showed lowered values mainly in the left basal ganglia and the left frontal white matter.

CONCLUSION

The results suggest that the increased risk of functional brain disorders observed in long-term cannabis users could be caused by an impairment of the energy metabolism of the brain, but this needs to be verified in future studies.

Socioeconomic and psychosocial determinants of substance misuse - a national perspective

Accurate estimates of population drug use and an understanding of the factors that influence substance choice are essential for the development of appropriate and targeted prevention strategies and campaigns. This review aims to provide an overview of the socioeconomic and psychosocial factors that influence substance use patterns within the Australian population through exploration of current and historical examples of substance misuse. Australia's comparatively large online drug market is reflective of the country's relative geographic isolation and high local drug prices. Legislation, particularly relating to cannabis cultivation and personal use, has evolved significantly in response to increased scientific and commercial applications and changing attitudes towards medical and personal use. Methylamphetamine use is disproportionately high, attributed to Australia's geographic location, high rates of local manufacture, steady cost, and increased purity. Despite the increased cost of cocaine over time, the profile of users appears to dictate rates of use. The prevalence of injecting drug use is driven by a lack of education, perceived risk, stigma, and other social factors. Additionally, psychosocial factors also contribute to substance misuse among specific population subgroups such as petrol sniffing among Indigenous Australians. Understanding the reasons for geographical variability in illicit drug use assists in the interpretation of substance-associated behavior in specific groups/populations and in guiding future intervention efforts and predictions of emerging trends. In addition, an understanding of factors influencing local drug usage may assist forensic practitioners in evaluating the occurrence and effects of particular substances that may emerge as significant factors in drug-related deaths.

Recreational Cannabis Legalization and Proximity to Cannabis Retailers as Risk Factors for Adolescents' Cannabis Use

Within-person studies are lacking regarding how recreational cannabis legalization (RCL) and the numbers of neighborhood cannabis retailers relate to adolescents' cannabis use. Study participants were 146 offspring (55% girls; 77% White non-Latinx) of men recruited in childhood from neighborhoods with high delinquency rates. Youth were assessed for past-year cannabis and alcohol use one or more times from ages 13 to 20 years (age M[SD] = 16.4 [2.1] years across 422 observations), while they were living in Oregon or Washington from 2005 to 2019 (where cannabis retail stores opened to adults ages 21 years and older in 2014 and 2015, respectively). We calculated distances between addresses of licensed cannabis retailers and participants' homes. Multilevel models that accounted for effects of age on cannabis use did not support that the number of retail stores within 2-, 5-, 10-, or 20-mile radii of adolescents' homes increased likelihood of past-year cannabis use at the within- or between-subjects levels. Likewise, primary models did not support a greater likelihood of cannabis use among youth whose adolescence coincided more fully with the post-RCL period. A secondary model suggested that after adjusting for adolescents' concurrent alcohol use as a marker of general substance use risk, RCL was associated with cannabis use (between-subjects B [95% CI] = .35 [.05-.66], p = .024). Further research is needed with larger prospective samples, at-risk subgroups, and as cannabis markets mature.

The Impact of Cannabis Use on Adolescent Neurodevelopment and Clinical Outcomes Amidst Changing State Policies

Cannabis is the most common illicit substance used by adolescents and the third most common psychoactive substance after alcohol and nicotine. Cannabis use during adolescence interrupts a critical period of brain development and leads to inappropriate activation of the reward pathway. Because the prefrontal cortex, which is responsible for impulse control and other executive functions, is not fully mature until the mid-twenties, the adolescent brain is especially vulnerable to damage from substance use. Although cannabis remains illegal at the federal level, recent changes in state policies have been associated with increased availability of a wide variety of cannabis products. As new products, formulations, and delivery devices that can deliver higher and faster peak doses of tetrahydrocannabinol enter the market, there is an even greater potential for cannabis to have negative clinical impacts on adolescent health. This article reviews the current literature on the impact of cannabis on adolescent health, including the neurobiology of the adolescent brain, potential clinical outcomes in adolescents who use cannabis, and the effects of changing state policies regarding cannabis on the increased availability of unregulated products.

Understanding the differential effect of local socio-economic conditions on the relation between prescription opioid supply and drug overdose deaths in US counties

BACKGROUND AND AIMS

Both local socio-economic conditions and prescription opioid supply are associated with drug overdose deaths, which exhibit substantial geographical heterogeneity across the United States. We measured whether the associations of prescription opioid supply with drug overdose deaths vary by local socio-economic conditions.

DESIGN

Ecological county-level study, including 3109 US counties between 2006 and 2019 (n = 43 526 county-years) using annual mortality data.

SETTING

United States.

CASES

A total of 711 447 drug overdose deaths.

MEASUREMENTS

We modeled overdose counts using Bayesian hierarchical Poisson models, estimating associations between four types of drug overdose deaths (deaths involving any drugs, any opioid, prescription opioids only and heroin), prescription opioid supply and five socio-economic indicators: unemployment, poverty rate, income inequality, Rey index (components include mean household income, % high school graduates, % blue-collar workers and unemployment rate), and American human development index (HDI; an indicator of community wellbeing).

FINDINGS

Drug overdose deaths and all substance-specific overdose deaths were higher in counties with higher income inequality [adjusted odds ratios (aORs) = 1.09-1.13], Rey index (aORs = 1.15-1.21) and prescription opioid supply (aORs = 1.14-1.21), and lower in counties with higher HDI scores (aORs = 0.75-0.92). Poverty rate, income inequality and HDI scores were found to modify the effect of prescription opioid supply on heroin overdose deaths. The plot of the interactions showed that when disadvantage is high, increasing prescription opioid supply does not increase heroin overdose deaths. The less disadvantage there is, indicated by lower poverty rates, higher HDI scores and lower income inequality, the greater the effect of increasing prescription opioid supply relative to population size on heroin overdose deaths in US counties.

CONCLUSIONS

In the United States, prescription opioid supply is associated with higher drug overdose deaths; associations are stronger in counties with less disadvantage and less income inequality, but only for heroin overdose deaths.

Comparing National College Health Assessment with other surveys of cannabis use and binge drinking among young adult college students 2008-2018

Objective: We considered the utility of National College Health Assessment (NCHA) data relative to other national data for studying college students' cannabis use and binge drinking, and drug policy effects. Participants: Survey data on 18-22-year old college students were drawn from the 2008-2018 NCHA, National Survey on Drug Use and Health (NSDUH), Monitoring the Future (MTF), and Healthy Minds Study (HMS). Methods: Prevalence estimates were compared across data sources in terms of level and change from 2008-2018 using linear regressions, separately for men and women. Results: Mean prevalence estimates for 30-day cannabis use and 2-week binge drinking, and linear time trends did not differ significantly among NCHA, NSDUH, and MTF. Conclusions: NCHA prevalence estimates are similar to those from NSDUH and MTF, NCHA has unique strengths, and some weaknesses can be offset. Findings support the value of NCHA for studying college students' substance use and effects of drug policy.

Student perceptions of cannabis use

OBJECTIVE

This qualitative study explored post-secondary students' perceptions of cannabis use on students' health, academic pursuits, and social lives, and investigated how these issues have been impacted by the legalization of recreational cannabis.

Participants: 20 undergraduate students at a small liberal arts university in Atlantic Canada participated in this study.

Methods: Semi-structured interviews were used to learn more about student perceptions of cannabis. Interview transcripts were analyzed using general thematic analysis.

Results: Students in this study report using cannabis in thoughtful ways, balancing various considerations in terms of health, social connections, and academics. They were aware that cannabis is not a risk-free drug and took some steps to manage risks.

Conclusion: Knowing why young adults believe they use cannabis is information for university professionals who want to develop effective harm reduction campaigns.

Assessing the Impact of Recreational Cannabis Legalization on Cannabis Use Disorder and Admissions to Treatment in the United States

Purpose of Review

Policy implications from changes in recreational cannabis laws (RCLs) have raised public health concerns. While numerous studies have examined the impact of RCLs on cannabis use, there is less research on the risk of developing cannabis use disorder (CUD). This review summarizes the latest research on the effects of RCLs on CUD prevalence and cannabis treatment admissions.

Recent Findings

Nine studies were published between 2016 - 2022 that examined RCLs and CUD or treatment. Findings generally indicate an increase in CUD prevalence associated with legalization, but effects differ by age group. There was no significant association between legalization and CUD treatment admissions, and CUD admissions decreased overall during the study periods.

Summary

To improve policy, prevention, and treatment services, policymakers should monitor RCLs' effects on adverse public health outcomes and researchers should consider the effects on individual and community-level characteristics. We discuss methodological challenges in conducting state-level research and provide suggestions for future studies.

Adolescent Cannabis Use During a Period of Rapid Policy Change: Evidence From the PATH Study

PURPOSE

To determine whether shifts in various state-level cannabis policies are associated with individual-level changes in adolescent cannabis use following implementation.

METHODS

We use the restricted-access youth cohort of the PATH Study, a recent, longitudinal, and nationally representative dataset, to assess whether changes in cannabis policy affect youth cannabis use. Data include respondents aged 12 to 17 years across up to six repeated observations (N = 26,673). Hybrid (between-person and within-person) panel models are used to examine adolescent past-month cannabis use.

RESULTS

Within-person effects showed that the odds of past-month cannabis use are lower (odds ratio [OR] = 0.632; p < .05) in years when a respondent's state allowed only cannabidiol (CBD) compared to years when the state had legalized medical cannabis. The odds of past-month cannabis use are lower during years when a respondent's state had decriminalized (OR = 0.617; p < .01) or criminalized (OR = 0.648; p < .05) adult recreational cannabis possession compared to years when it was legalized. These effects were robust to numerous controls, including time and state fixed effects. By contrast, significant between-person effects became nonsignificant with state fixed effects included, implying that state-level average use distinguishes average differences between states rather than policy.

DISCUSSION

Liberalized cannabis policy is significantly associated with recent adolescent cannabis use. The most consequential policy shift associated with adolescent use is from either criminalization or decriminalization of cannabis possession to legalization, such that states making these changes should consider additional prevention efforts.

The impact of recreational cannabis markets on motor vehicle accident, suicide, and opioid overdose fatalities

In the U.S., an increasing number of states are legalizing regulated commercial markets for recreational cannabis, which allows private industry to produce, distribute, and sell marijuana to those 21 and older. The health impacts of these markets are not fully understood. Preliminary evidence suggests recreational markets may be associated with increased use among adults, which indicates there may be downstream health impacts on outcomes related to cannabis use. Three causes of death that are linked to cannabis use are motor vehicle accidents, suicide, and opioid overdose. Drawing on data from U.S. death certificates from 2009 to 2019, we conducted a difference-in-differences analysis to estimate the impact of recreational markets on fatalities from motor vehicle accidents, suicide, and opioid overdose in seven states: Colorado, Washington, Oregon, Alaska, Nevada, California, and Massachusetts. States with comprehensive medical cannabis programs with similar pre-trends in deaths were used as comparisons. For each outcome, a pooled estimate was generated with a meta-analysis using random effects models. The results revealed substantial increases in crash fatalities in Colorado, Oregon, Alaska, and California of 16%, 22%, 20%, and 14%, respectively. Based on estimates from all seven states, recreational markets were associated with a 10% increase in motor vehicle accident deaths, on average. This study found no evidence that recreational markets impacted suicides. Most states saw a relative reduction in opioid overdose death that ranged between 3 and 28%. On average, recreational markets were associated with an 11% reduction in opioid overdose fatalities.

Recreational marijuana laws and the misuse of prescription opioids: Evidence from National Survey on Drug Use and Health microdata

Several studies have concluded that legalizing medical marijuana can reduce deaths from opioid overdoses. Drawing on micro data from the National Survey on Drug Use and Health, a survey uniquely suited to assessing patterns of substance use, we examine the relationship between recreational marijuana laws (RMLs) and the misuse of prescription opioids. Using a standard difference-in-differences (DD) regression model, we find that RML adoption reduces the likelihood of frequently misusing prescription opioids such as OxyContin, Percocet, and Vicodin. However, using a two-stage procedure designed to account for staggered treatment and dynamic effects, the DD estimate of relationship between RML adoption and the likelihood of frequently misusing prescription opioids becomes positive. Although event study estimates suggest that RML adoption leads to a decrease in the frequency of prescription opioid abuse, this effect appears to dissipate after only 2 or 3 years.

The ethics and management of cannabis use in pregnancy following decriminalisation and licensing for medical use: narrative review

AIMS AND METHOD

As drug policies pertaining to cannabis use become more liberalised, the prevalence of cannabis use in pregnancy could increase. However, there is limited guidance available for clinicians. This paper presents a narrative review of literature published in the past 16 years (2006-2021) to (a) address the impact of legalisation and decriminalisation on the risks, ethics and support of women who use cannabis during pregnancy and (b) develop guidance for clinicians.

RESULTS

Both national and international trends suggest increased use of cannabis over the past decade, while the risks of cannabis use for recreational or medicinal purposes in pregnancy remain unmitigated.

CLINICAL IMPLICATIONS

This review confirmed that the recommendation of cannabinoid-based products for pregnant and breast-feeding women is currently premature. More research is needed to address safety concerns. We discussed navigating ethical concerns and suggest targeted management strategies for clinicians treating pregnant women who choose to use cannabis.

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

Background

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

Methods

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

Results

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

Conclusion

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

Cannabis vaping among high school seniors in adult-use, medical, and prohibited legal contexts

Background

Vaping cannabis among adolescents has been increasing. Monitoring the Future (MTF) indicated in 2019 that past-month cannabis vaping among 12th graders underwent the second-highest single-year jump ever tracked by MTF for any substance in its 45-year history. These increases in adolescents who vape cannabis do not parallel declining general adolescent cannabis use trends. Nevertheless, research on cannabis consumption via vaping, especially among adolescents, has been substantially limited.

Method

We examined associations between legal contexts (prohibited, medical, and adult use) and vaping cannabis in the past year among high school seniors. In addition, associations between vaping cannabis and factors such as availability and acceptability were examined using secondary data from MTF (2020), with a sub-sample size of 556 participants (overall sample size: n = 3,770), using multivariate logistic regression models.

Results

We found that high school seniors in medical states had higher odds of past-year vaping cannabis, but 12th graders in adult-use states were not significantly more likely to vape cannabis than those in prohibited states. Increased availability of vaping products and decreased risk perceptions in medical states may explain this relationship. Adolescents who perceived high risks associated with regular cannabis use had decreased odds of vaping cannabis. High school seniors reporting very easy access to cannabis cartridges had increased odds of vaping cannabis, regardless of legal context.

Conclusion

These results contribute knowledge about contextual factors related to adolescent cannabis vaping, a relatively new technique of cannabis consumption for which there is growing societal concern.

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.

Impact of Cannabis Legalization on Adolescent Cannabis Use

Because of substantial limitations in available national data, such as inconsistencies among surveys and small sample sizes, the increased prevalence of cannabis use among adolescents since recreational legalization has not been directly observed. Nevertheless, both usage frequency and product potency have significantly increased, alongside alternative routes of delivery to smoking, such as vaping cannabis. Moreover, certain populations may be especially vulnerable to the effects of legalization. Regardless of differing state-level cannabis legalization status, the adverse consequences of cannabis on youth have clear negative impacts on mental health, medical symptoms, educational outcomes, and increased risk of addiction to other substances.

The kids aren't alright: The effects of medical marijuana market size on adolescents

We exploit shocks to US federal enforcement policy to assess how legal medical marijuana market size affects youth marijuana use and consequences for youth traffic-related fatalities. Using hand-collected data on state medical marijuana patient rates to develop a novel measure of market size, we find that legal market growth increases youth marijuana use. Likely mechanisms are lower prices and easier access. Youth die more frequently from alcohol-involved car accidents, suggesting complementarities for youths. The consequences of marijuana legalization for youth are not immediate, but depend on how supply-side regulations affect production and prices.

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.

Sex Differences in the Relationship Between Early Adverse Childhood Experiences, Delinquency, and Substance Use Initiation in High-Risk Adolescents

Adverse childhood experiences (ACEs) have been linked to a host of subsequent negative health and behavioral problems. However, the role of sex in the ramifications of early ACEs remains unclear, particularly for delinquency and substance use initiation in adolescence. A small body of research has produced mixed findings on sex differences in the relationship between ACEs and antisocial outcomes in adolescence, resulting in uncertainty about whether and how ACEs may operate differently for boys and girls. The current study drew on a high-risk group of adolescents (N=2455; M_age=15.4; 48% female; 50% Black, 23% Hispanic) from the Fragile Families and Child Wellbeing Study to examine the associations between accumulated ACEs across early childhood, and delinquency and substance use initiation of alcohol, cigarette, and cannabis in adolescence. We utilized mother and father reports on the exposure to seven different types of ACEs (i.e., physical abuse, psychological abuse, neglect, parental substance misuse, parental mental illness, parental intimate partner violence, and parental criminal behavior) when adolescents were ages 1, 3, and 5. Total ACEs scores and their relationships with delinquency, and lifetime use of alcohol, cigarettes, and cannabis were assessed separately for girls and boys. Results suggested that accumulated ACEs during early childhood may be implicated in boys' delinquency, while ACEs were not significantly associated with girls' self-reported delinquency or for boys' and girls' substance use initiation. Findings suggest that the enduring consequences of ACEs may be sex-specific, and have implications for the development of policies to mitigate ACEs and their harms.

Association of Recreational Cannabis Legalization With Cannabis Possession Arrest Rates in the US

Importance

Recreational cannabis legalization (RCL) has been advocated as a way to reduce the number of individuals interacting with the US criminal justice system; in theory, however, cannabis decriminalization can achieve this objective without generating the negative public health consequences associated with RCL. It is still unclear whether RCL can bring additional benefits in terms of reducing cannabis possession arrests in states that have already decriminalized cannabis.

Objective

To examine whether RCL was associated with changes in cannabis possession arrests in US states that had already decriminalized cannabis during the study period and whether these changes differed across age and racial subgroups.

Design, Setting, and Participants

This repeated cross-sectional study used cannabis possession arrest data from the Federal Bureau of Investigation Uniform Crime Reporting Program (UCRP) for US states from 2010 through 2019. Statistical analysis was conducted from October 6, 2021, to October 12, 2022.

Exposures

Implementation of statewide RCL.

Main Outcomes and Measures

Cannabis possession arrest rates per 1000 population per year were assessed with a quasi-experimental difference-in-differences design and were used to estimate the association of RCL with arrest rates in RCL states that had or had not decriminalized cannabis before RCL. This association was also examined in subgroups for age (adults vs youths) and race (Black vs White).

Results

This study included UCRP data for 31 US states, including 9 states that implemented RCL during the study period (4 without and 5 with decriminalization) and 22 non-RCL states. In the 4 states that had not decriminalized cannabis before legalization, RCL was associated with a 76.3% decrease (95% CI, -81.2% to -69.9%) in arrest rates among adults. In the 5 states that had already decriminalized cannabis, RCL was still associated with a substantial decrease in adult arrest rates (-40.0%; 95% CI, -55.1% to -19.8%). There was no association of RCL with changes in arrest rates among youths. In addition, changes in arrest rates associated with RCL did not differ among Black and White individuals.

Conclusions and Relevance

In this repeated cross-sectional study, RCL was associated with a sizable reduction in cannabis possession arrests among adults in states that had already decriminalized cannabis during the study period (2010-2019), albeit the magnitude was smaller compared with states that had not decriminalized cannabis before RCL. In addition, RCL did not seem to be associated with changes in arrest rates among youths or disparities in arrest rates among Black and White individuals.

School Nurse Perspectives of Medical Cannabis Policy in K-12 Schools: An Exploratory Descriptive Study

As states legalize medical cannabis, school nurses face increased parent questions about administration at school. Although school nurses frequently collaborate on the development and implementation of medication administration policies, their perceptions of barriers to school-based medical cannabis administration are not well-documented. To explore these perceptions, we surveyed school nurses (n = 379) in sixteen states about their beliefs related to school-based medical cannabis administration policy development. Findings revealed school nurses from states completely legalizing cannabis expressed significantly fewer concerns about the safety, stigma, and federal status of medical cannabis than their peers in more restrictive states. Implications for practice include (a) education of key stakeholders, (b) collaboration with stakeholders to formulate medication administration policy; and (c) development of state-level guidance for school professionals.

The influence of parent and peer disapproval on youth marijuana use mediated by youth risk perception: Focusing on the state comparison

BACKGROUND

The prevention of youth marijuana use has become a national priority in the United States. This study examined the influence of parent and peer disapproval on youth marijuana use, mediated by youth risk perception. Because the legal status of marijuana use can influence individual perceptions of the drug, this study investigated differences in the mediating mechanism between youth living in states with medical marijuana legalization (MML) and those living in non-MML states.

METHODS

The 2019 National Survey of Drug Use and Health was used with a youth population aged 12-17 years (N = 2293). Structural equation modeling and bias-corrected bootstrapping were used to examine hypothesized path models and to evaluate the mediating effect of youth risk perception.

RESULT

Findings demonstrated that parent and peer disapproval significantly increased youth risk perception of marijuana and reduced youth marijuana use. Second, youth risk perception significantly mediated the association between parent and peer disapproval and youth marijuana use. Third, parent disapproval had a more significant direct effect on youth marijuana use, while peer disapproval had a more significant indirect effect on youth marijuana use via youth risk perception. Finally, the results showed a similar pattern in the mechanism between youths living in MML states compared with those in non-MML states in terms of significance and direction.

CONCLUSION

The findings suggested a need for improvements in marijuana related policies for both MML and non-MML states. Moreover, parent and peer focused strategies for education and prevention concerning marijuana use among youth are emphasized.

Does recreational cannabis legalization change cannabis use patterns? Evidence from secondary school students in Uruguay

BACKGROUND AND AIMS

In 2013, Uruguay became the first country to legalize and regulate the production and distribution of cannabis for recreational use. We measured whether Uruguay's non-commercial model of recreational cannabis legalization was associated with changes in the prevalence of risky and frequent cannabis use among secondary school students.

DESIGN

We used data from repeated cross-sectional surveys of secondary students in Uruguay and Chile (2007-2018). Using a difference-in-difference approach, we evaluated changes in the prevalence of past-year, past-month, any risky and frequent cannabis use following enactment (2014) and implementation (2016) of cannabis legalization among the full sample of secondary students and among students who reported past-year/month use. We examined changes separately for students ages 12 to 17, and students for whom cannabis became legally accessible, ages 18 to 21.

SETTING

Uruguay and Chile (2007-2018).

PARTICIPANTS

Secondary school students in 8th, 10th and 12th grade (n = 204 730).

MEASUREMENTS

Past-year and past-month cannabis use; any risky cannabis use measured with the Cannabis Abuse Screening Test (CAST); and frequent cannabis use (10+ days in the past-month).

FINDINGS

We found a decrease in past-year and past-month use following enactment or implementation. Among students ages 18 to 21, post-enactment, we observed a transitory increase in 2014 that decreased thereafter for: any risky use among those who reported past-year use (prevalence difference [PD] = 13.5%; 95% CI: 2.0, 24.9), frequent use in the full sample (PD = 4.5%; 95% CI: 1.0, 8.1), and frequent use among those who reported past-month use (PD = 16.8%; 95% CI: 1.9, 31.8).

CONCLUSION

The legalization of recreational cannabis in Uruguay was not associated with overall increases in either past-year/past-month cannabis use or with multi-year changes in any risky and frequent cannabis use among young people.

Sharing pro-marijuana messaging on social media: The moderating role of legislation

ObjectivesThis study investigates whether recreational marijuana legislation and perceived social norms (descriptive and injunctive) affect college students' propensity to share pro-marijuana messages. We examine which referent group (close friends, typical student, parents) most influence those norms. Participants: A sample of 343 college students participated in the study. Of these students, 214 were from Washington State, where recreational marijuana is legal, and 129 were from Wyoming, where recreational marijuana is illegal. Method: Data, from an online survey, were analyzed through PROCESS analyses. Results: College students in Washington State who believed a typical peer would want them to share pro-marijuana messaging were marginally more likely to share pro-marijuana messages than their counterparts in Wyoming. However, among students who thought a typical peer would not approve of them sharing pro-marijuana messaging, the opposite pattern emerged. Conclusion: Restrictive recreational marijuana legislation does not uniformly abate related message sharing on social media.

The inverse association of state cannabis vaping prevalence with the e-cigarette or vaping product-use associated lung injury

The e-cigarette or vaping product-use-associated lung injury (EVALI) epidemic was primarily associated with the use of e-cigarettes containing tetrahydrocannabinol (THC)- the principal psychoactive substance in cannabis, and vitamin-E-acetate- an additive sometimes used in informally sourced THC-containing e-liquids. EVALI case burden varied across states, but it is unclear whether this was associated with state-level cannabis vaping prevalence. We, therefore, used linear regression models to assess the cross-sectional association between state-level cannabis vaping prevalence (obtained from the 2019 behavioral Risk Factor Surveillance System) and EVALI case burden (obtained from the Centers for Disease Control and Prevention) adjusted for state cannabis policies. Cannabis vaping prevalence ranged from 1.14%(95%CI, 0.61%-2.12%) in Wyoming to 3.11%(95%CI, 2.16%-4.44%) in New Hampshire. EVALI cases per million population ranged from 1.90(0.38-3.42) in Oklahoma to 59.10(19.70-96.53) in North Dakota. There was no significant positive association but an inverse association between state cannabis vaping prevalence and EVALI case burden (Coefficient, -18.6; 95%CI, -37.5-0.4; p-value, 0.05). Thus, state-level cannabis vaping prevalence was not positively associated with EVALI prevalence, suggesting that there may not be a simple direct link between state cannabis vaping prevalence and EVALI cases, but rather the relationship is likely more nuanced and possibly reflective of access to informal sources of THC-containing e-cigarettes.

Recreational cannabis legalization and transitions in cannabis use: findings from a nationally representative longitudinal cohort in the United States

AIMS

This study estimated the likelihoods of individuals transitioning to different cannabis use status following recreational cannabis legalization (RCL) in the United States.

DESIGN

Secondary analysis of a nationally representative longitudinal cohort in the United States. We used propensity score matching to balance individual characteristics between RCL and comparison states and generalized mixed regressions to estimate behavioral transitions in matched samples.

PARTICIPANTS

A longitudinal cohort of 21 863 individuals (6925 youths and 14 938 adults) participating in the Population Assessment of Tobacco and Health waves 3 and 4.

SETTING

Four RCL states that implemented RCL between waves 3 and 4 (California, Massachusetts, Nevada and Maine) and comparison states in the United States.

MEASUREMENTS

Transitions in cannabis use over the two waves: (1) from non-users to users; (2) from non-users to weekly users; (3) from users to non-users. Individuals in RCL states were compared with matched individuals in (1) states with medical cannabis legalization (MCL), (2) states not legalizing cannabis (non-legalizing) and (3) MCL and non-legalizing states combined.

FINDINGS

Among youths, the association between RCL and greater odds of transition from non-users to users was seen in comparison with non-legalizing states [odds ratio (OR) = 2.18, 95% confidence interval (CI) = 1.37-3.45] and combined states (OR = 1.73, 95% CI = 1.23-2.42). Evidence was lacking regarding the associations between RCL and transitions from non-users to weekly users and from users to non-users. Among adults, RCL was associated with greater odds of transitions from non-users to users and non-users to weekly users if RCL states were compared with non-legalizing states (OR = 1.68, 95% CI = 1.15-2.46; OR = 1.82, 95% CI = 1.00-3.31, respectively) or combined states (OR = 1.51, 95% CI = 1.11-2.07; OR = 2.09, 95% CI = 1.19-3.66, respectively). RCL was also associated with lower odds of transition from users to non-users if RCL states were compared with non-legalizing states (OR = 0.54, 95% CI = 0.35-0.81).

CONCLUSIONS

There appears to be some evidence that recreational cannabis legalization in the United States is associated with elevated odds of transition to cannabis use among both youths and adults.

What is the likelihood that underage youth can obtain marijuana from licensed recreational marijuana outlets in California, a state where recreational marijuana is legal?

OBJECTIVE

Since 2012, 19 states and the District of Columbia have legalized the recreational use of marijuana for adults ages 21 and older. Marijuana use at any level can impair driving performance. Prior research on enforcement of the minimum legal marijuana use age of 21 (MLMU-21) laws is limited. The objective of the current study was to assess the ease of access to marijuana by underage patrons at recreational marijuana outlets in California, where recreational marijuana was legalized in 2016.

METHOD

Pseudo-underage patrons were sent to 50 randomly selected licensed recreational marijuana outlets in the state to see if they could enter the outlet without showing a valid identification of their age.

RESULTS

Pseudo-underage patrons were required to show age identification to enter in 100% of the licensed recreational marijuana outlets visited.

CONCLUSIONS

It appears that licensed California recreational marijuana outlets avoid selling marijuana to underage customers. One reason could be a strong incentive for recreational marijuana outlet owners and managers to avoid being shut down for an illegal activity.

PRACTICAL APPLICATION

Underage youth are not obtaining marijuana at licensed recreational outlets. Future studies and cannabis enforcement agencies should investigate whether underage patrons attempt to use fake IDs at licensed marijuana outlets and whether youth are obtaining marijuana from illicit dispensaries or from social sources.