Reefer madness or much ado about nothing? Cannabis legalization outcomes among young adults in the United States

Medicinal cannabis use among young adults during California's transition from legalized medical use to adult-use: a longitudinal analysis

Background: In 2016, California transitioned from legalized medical cannabis use to adult-use. Little is known about how this policy change affected medicinal cannabis use among young adults.Objectives: To identify longitudinal groups of medicinal cannabis users and concurrent changes in health- and cannabis use-related characteristics among young adults in Los Angeles between 2014 and 2021.Methods: Cannabis users (210 patients and 156 non-patients; 34% female; ages 18-26 at baseline) were surveyed annually across six waves. Longitudinal latent class analysis derived groups from two factors - cannabis patient status and self-reported medicinal use. Trajectories of health symptoms, cannabis use motives, and cannabis use (daily/near daily use, concentrate use, and problematic use) were estimated across groups.Results: Three longitudinal latent classes emerged: Recreational Users (39.3%) - low self-reported medicinal use and low-to-decreasing patient status; Recreational Patients (40.4%) - low self-reported medicinal use and high-to-decreasing patient status; Medicinal Patients (20.3%) - high self-reported medicinal use and high-to-decreasing patient status. At baseline, Medicinal Patients had higher levels of physical health symptoms and motives than recreational groups (p < .05); both patient groups reported higher level of daily/near daily and concentrate use (p < .01). Over time, mental health symptoms increased in recreational groups (p < .05) and problematic cannabis use increased among Recreational Patients (p < .01).Conclusions: During the transition to legalized adult-use, patterns of medicinal cannabis use varied among young adults. Clinicians should monitor increases in mental health symptoms and cannabis-related problems among young adults who report recreational - but not medicinal - cannabis use.

Marijuana Message Channels, Health Knowledge, Law Knowledge, and Confidence in Knowledge as Risk and Protective Factors of Marijuana Use among College Students

Marijuana use among U.S. college students is the highest since the mid-1980s. Because knowledge about marijuana and confidence in the knowledge are related to changing marijuana laws and marijuana-related messages ubiquitous in college students' information environment, we examined their relationships with use. The Structural Equation Modeling method was used to analyze the relationships using survey responses from 249 college students in an adult-use marijuana legal state. Marijuana health knowledge was related to less use, and law knowledge was related to more use. Both relationships were mediated by perceived risk. Confidence in knowledge was related to more use directly as well as indirectly via lower peer disapproval and lower perceived risk. Among various marijuana message channels, peers were the most influential, contributing to lower health knowledge and higher confidence in knowledge.

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.

Cannabis use and social anxiety disorder in emerging adulthood: Results from a nationally representative sample

Cannabis use and social anxiety disorder (SAD) are prevalent during emerging adulthood. Previous work has demonstrated that SAD is related to cannabis use in adults; however, less is known about what correlates relate to this association in emerging adults. A subsample of individuals ages 18-25 years old from the NESARC-III (N = 5194) was used to (a) evaluate the association between cannabis use and SAD and (b) examine what correlates may be associated with cannabis use and SAD in emerging adulthood. Weighted cross-tabulations assessed sociodemographics and lifetime psychiatric disorder prevalence estimates among the emerging adult sample. Multinomial logistic regressions examined associations between sociodemographics and psychiatric disorders and four groups (i.e., no cannabis use or SAD; cannabis use only; SAD only; cannabis use + SAD). The prevalence of co-occurring cannabis use and SAD was 1.10%. Being White, a part-time student, or not a student were associated with increased odds of having co-occurring cannabis use + SAD (OR range: 2.26-3.09). Significant associations also emerged between major depressive disorder, bipolar I disorder, generalized anxiety disorder, specific phobia, agoraphobia, and panic disorder and co-occurring cannabis use + SAD (AOR range: 3.03-19.05). Results of this study may have implications for better identifying and screening emerging adults who are at risk of co-occurring cannabis use and SAD.

Longitudinal patterns of cannabis and tobacco co-administration and concurrent use among young adult college students

INTRODUCTION

Co-use, including concurrent use or co-administration, of cannabis and tobacco is most prevalent in young adulthood and associated with worse health outcomes than use of either substance alone. This study examined latent classes of tobacco and cannabis concurrent use and co-administration, and transitions between classes from 2016 to 2019, among a sample of young adult college students in Texas.

METHODS

Participants included 4,448 young adults (64.2% female, 64.7% non-white, mean age = 20.5) in a longitudinal cohort study. Measures included past 30-day use of cigarettes. hookah, cigars, ENDS, cannabis, and cannabis and tobacco co-administration. Latent Markov models were used to estimate latent class membership and transitions between classes from 2016 to 2017 and 2017 to 2019.

RESULTS

Four latent classes emerged: non-use (58% of students) characterized by low/no probability of any use; general use (19%) characterized by some level of use of all behaviors; blunt and cannabis use class (13%) characterized by high probabilities of cannabis use and co-administration with blunts; and concurrent and co-administration use (10%) with high probabilities of cigarette, cannabis, blunt, and spliff use. Most students remained in the same latent class from 2016 to 2019.

CONCLUSIONS

While most students reported low/no tobacco and cannabis co-use, those who used cannabis and/or tobacco remained in their use classes over the course of the study (2016 to 2019). Public health advocates on college campuses should consider prevention and cessation programs that incorporate the constellation of behaviors related to cannabis and tobacco co-use and educate students about the health consequences of co-use.

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.

Cannabis industry campaign expenditures in Colorado, 2005-2021

BACKGROUND

The cannabis industry has been described using the commercial determinants of health framework because it seeks to increase sales and profits through efforts to change the political environment. To increase understanding of these cannabis industry's efforts, this study describes cannabis industry campaign contributions in Colorado through an analysis of public records.

METHODS

We reviewed datasets posted online at the Colorado Secretary of State's Transparent in Contribution and Expenditure Reporting (TRACER) Campaign Finance System. We generated descriptive data on cannabis industry contributions to elections and conducted regressions to identify predictors of contributions, and associations between lagged contributions and a legislator's cannabis industry score (how closely aligned lawmaker's legislative history is with the cannabis industry from -1 to 1).

RESULTS

Between 2005-2021, 429 cannabis-affiliated contributors gave $4,658,385 (2021 inflation-adjusted) to 512 electoral committees. Contributions came primarily from non-profits (45%), businesses (27%), and individuals (25%). After recreational legalization in 2012, contributions from non-profit donors with industry ties gave way to contributions from cannabis businesses, business owners, and lobbyists. Cannabis industry contributions to local and state-wide ballot initiative campaigns historically made up the majority of the industry spending, but contributions to candidate committees more than tripled between the 2009-2010 legislative cycle and the 2019-2020 cycle. From 2017-2020, every $10,000 in lagged campaign donations from cannabis industry affiliated contributors was associated with a 0.245-point increase in a legislator's cannabis industry score (p=0.04).

CONCLUSION

Cannabis-affiliated interests made substantial campaign contributions in Colorado. Public health advocates should monitor industry connections to lawmakers and industry tactics used to mask the source of political contributions. Continued surveillance of the cannabis industry is essential to exposing conflicts of interest and preventing undue industry influence.

Association of self-reported use of cannabis for the purpose of improving physical, mental, and sleep health with problematic cannabis use risk

BACKGROUND

Little is known about health-focused cannabis use purposes and their associations with risk for problematic cannabis use. This cross-sectional study examined three broad cannabis use purposes and association with risk for problematic use among young adult cannabis users who report using for > 1 health reasons.

METHODS

Young adults completed an electronic survey as part of an ongoing study on substance use and health. Those who self-reported past 6-month use of ≥ 1 cannabis products-smoking, vaping, dabbing, eating, and blunts-were included in the analysis. Their purposes for use were coded into three categories: sleep, mental, and physical health. Problematic cannabis use (PCU) was measured with the three-level structure Cannabis Abuse Screening Test (CAST-3). Adjusted multivariable regression models were used to estimate use purposes associated with with problematic cannabis use at the p < 0.05 level.

RESULTS

Participants (n = 954) were mostly female (63.94%) and Hispanic (54.93%). Mental health was the most endorsed reason (73.38%) for use among study sample. Among participants, 36.3% were classified as being at severe risk (CAST-3 score ≥ 8). There was a significant association between PCU risk and reporting cannabis use for physical health (p < 0.01), mental health, and sleep health (p < 0.01) purposes. Those who used cannabis for physical heath purposes had about four times the risk (adjusted relative risk ratio (aRRR) = 4.38, 95% CI = 3.06-6.69), those who used for mental health had about three times the risk (aRRR = 2.81, 95% CI = 1.86-4.72), and those who used for sleep health had almost two times the risk (aRRR = 1.83, 95% CI = 1.17-2.63) for severe PCU.

CONCLUSION

All cannabis use purposes examined increased risk of problematic cannabis use. Physical health use purposes was associated with highest PCU risk. This study demonstrates the risk for cannabis use disorder associated with self-medicating with cannabis.

Changes in Quantity Measures of Various Forms of Cannabis Consumption among Emerging Adults in Canada in Relation to Policy and Public Health Developments

Limited research examines changes in quantities of various forms of smoked/vaped cannabis among regular consumers, including emerging adults (EAs; 18 to 29) in Canada. This information is particularly relevant in the current context of emerging cannabis behaviors among EAs related to political amendments (legalization of cannabis), vaping-related lung illnesses (EVALI), and unprecedented pandemics (COVID-19). This study investigated the impact of legalizing recreational cannabis use in Canada, the EVALI epidemic, and the COVID-19 pandemic on the quantity of smoked/vaped forms of cannabis in relation to gender differences. EAs retrospectively self-reported the quantity of herb, hash, concentrates, joint size, and the number of joints and vaping cartridges in relation to three consecutive developments: pre-legalization, post-legalization; pre-EVALI, post-EVALI, pre-COVID-19, and during COVID-19. The quantity of herb use significantly increased among heavy users, and vaping quantity significantly increased among light users. Overall, an increasing incremental trend was observed in the average quantity of cannabis forms used over time. Males consumed higher quantities of all cannabis forms than females. More males than females reported using concentrates (p < 0.05). These findings reveal unique aspects of the amount of various cannabis forms smoked/vaped in relation to gender and provides preliminary evidence of cannabis consumption behaviors in relation to changing social and cultural contexts.

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.

Expectancies that Predict Cannabis Initiation in Response to Legalization

Background: Recent and prospective changes to nonmedical/recreational cannabis laws in the United States and abroad raise questions about how legalization may influence cannabis use behaviors. Objectives: In the current study, we examined links between legalization, context-specific likelihood of using cannabis, and cannabis expectancies using cross-sectional survey data from 121 college students who had never used or were abstaining from cannabis in a U.S. state where laws prohibit nonmedical cannabis. Results: We found that across scenarios, 61% of students reported they would be more likely to use cannabis if it were legal. Social/sexual facilitation expectancies predicted a higher likelihood of using cannabis after legalization in a social context. Relaxation/tension reduction expectancies predicted a higher likelihood of using in an anxiety relief context. Perceptual/cognitive enhancement expectancies predicted a higher likelihood of using in a pain relief context. Cognitive/behavioral impairment expectancies predicted a lower likelihood of using in social, pain relief, relaxation, and concert contexts. Global negative effects expectancies predicted a lower likelihood of using in relaxation and concert contexts. Conclusions: Our findings suggest that among college students who do not use cannabis, expectancies are linked to cannabis use likelihood in certain contexts if cannabis were legal. This work highlights cannabis expectancies and contexts as possible targets for evidence-based public health education and clinical prevention initiatives related to the potential increase in cannabis use associated with cannabis policy implementation. College students may benefit from initiatives that address cannabis expectancies and enhance harm reduction skills to help them effectively navigate contexts in which cannabis is available to them.

Impact of Canada's cannabis legalisation on youth emergency department visits for cannabis-related disorders and poisoning in Ontario and Alberta, 2015-2019

INTRODUCTION

Although there is momentum towards legalising adult recreational cannabis use worldwide, the extent of youth cannabis-related harm associated with legalisation is still uncertain. The current study aimed to assess whether the initial implementation of Canada's cannabis legalisation (via the Cannabis Act) on 17 October 2018 might be associated with youth harm, as assessed by emergency department visits for cannabis-related disorders/poisoning.

METHODS

We used Ontario and Alberta, Canada emergency department data from 1 April 2015 to 31 December 2019. We identified all cannabis-related disorders/poisoning (ICD-10 CA: F12.X, T40.7) emergency department visits of youth (n = 13,615), defined as patients younger than the minimum legal cannabis sales age (18 years, Alberta; 19 years, Ontario). Seasonal Autoregressive Integrated Moving Average (SARIMA) models were employed to assess the impact of legalisation on weekly counts of cannabis-related harms.

RESULTS

The final SARIMA intervention (step) parameter indicated a post-legalisation increase of 14.7 (95% confidence interval [CI] 5.0; 24.3, p < 0.01) weekly youth cannabis-related disorder/poisoning presentations to Ontario/Alberta emergency department settings, equivalent to an increase of 20.0% (95% CI 6.2%; 33.9%). There was no evidence of associations between cannabis legalisation and comparison series of youth alcohol, opioid or appendicitis emergency department episodes.

DISCUSSION/CONCLUSION

Our findings require replication and extension but are consistent with the possibility that the implementation of the Cannabis Act was associated with an increase in youth cannabis-related presentations to Ontario/Alberta emergency departments.

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.

Recreational cannabis legalization has had limited effects on a wide range of adult psychiatric and psychosocial outcomes

BACKGROUND

The causal impacts of recreational cannabis legalization are not well understood due to the number of potential confounds. We sought to quantify possible causal effects of recreational cannabis legalization on substance use, substance use disorder, and psychosocial functioning, and whether vulnerable individuals are more susceptible to the effects of cannabis legalization than others.

METHODS

We used a longitudinal, co-twin control design in 4043 twins (N = 240 pairs discordant on residence), first assessed in adolescence and now age 24-49, currently residing in states with different cannabis policies (40% resided in a recreationally legal state). We tested the effect of legalization on outcomes of interest and whether legalization interacts with established vulnerability factors (age, sex, or externalizing psychopathology).

RESULTS

In the co-twin control design accounting for earlier cannabis frequency and alcohol use disorder (AUD) symptoms respectively, the twin living in a recreational state used cannabis on average more often (βw = 0.11, p = 1.3 × 10-3), and had fewer AUD symptoms (βw = -0.11, p = 6.7 × 10-3) than their co-twin living in an non-recreational state. Cannabis legalization was associated with no other adverse outcome in the co-twin design, including cannabis use disorder. No risk factor significantly interacted with legalization status to predict any outcome.

CONCLUSIONS

Recreational legalization was associated with increased cannabis use and decreased AUD symptoms but was not associated with other maladaptations. These effects were maintained within twin pairs discordant for residence. Moreover, vulnerabilities to cannabis use were not exacerbated by the legal cannabis environment. Future research may investigate causal links between cannabis consumption and outcomes.

Impacts of recreational cannabis legalization on cannabis use: a longitudinal discordant twin study

AIMS

To estimate the effect of recreational legalization on cannabis use frequency and sources of variance across legal environments.

DESIGN

Longitudinal discordant twin and gene-environment interaction models in twins recruited from birth records and assessed prospectively.

SETTING

The United States, including states with different recreational cannabis policies before and after 2014, when recreational cannabis was first legalized.

PARTICIPANTS

Two longitudinal, prospectively assessed samples of American twins aged 24-47 (n = 1425 in legal states, n = 1996 in illegal states), including 111 monozygotic pairs discordant for residence.

MEASUREMENTS

Current cannabis use frequency (measured continuously and ordinally) was the primary outcome, and the predictor was recreational status of cannabis (legal/illegal) in the participant's state of residence at the time of assessment. Covariates include age, sex and cannabis use frequency prior to 2014.

FINDINGS

Accounting for pre-2014 use, residents of legal states used cannabis more frequently than residents of illegal states (b = 0.21, P = 8.08 × 10-5 ). Comparing 111 pairs of monozygotic twins discordant for residence confirmed the effect (b = 0.18, P = 0.014). There was inconclusive evidence for genetic influences on cannabis use frequency that were specific to the legal environment [χ2  = 2.9 × 10-9 , degrees of freedom (d.f.) = 1, P > 0.999]. Existing genetic influences were moderated by the legal environment, as the genetic correlation between marijuana use before and after legalization was lower in states that legalized (rgenetic  = 0.24) compared with states that did not (rgenetic  = 0.78, Pdifference  = 0.016).

CONCLUSIONS

In the United States, there appears to be a ~ 20% average increase in cannabis use frequency attributable to recreational legalization, consistent across increasingly rigorous designs. In addition, the heritability of cannabis use frequency appears to be moderated by legalization.

A randomized pilot trial of a mobile phone-based brief intervention with personalized feedback and interactive text messaging to reduce driving after cannabis use and riding with a cannabis impaired driver

INTRODUCTION

Driving after cannabis use (DACU) and riding with a cannabis-impaired driver (RWCD) are national public health concerns. Though driving impairments and increased crash risk make DACU and RWCD two of the riskiest cannabis-related behaviors, many continue to drive after use and ride with others who are under the influence and do not view DACU or RWCD as dangerous. The current study examined the efficacy of an accessible, low-cost, mobile phone-based brief intervention aimed at reducing DACU and RWCD among college cannabis users in the context of a randomized three-group pilot trial.

METHOD

Participants were 97 college cannabis users (67.4 % women; average age = 21.34; 80.4 % Caucasian) who endorsed DACU at least three times in the past three months. After completing baseline measures, the study randomly assigned participants to one of three conditions: a) a substance impaired-driving personalized feedback plus MI-style interactive text messaging intervention (PF + MIT); b) a substance impaired-driving personalized feedback only intervention (PF); and c) a substance information control condition (IC). All conditions completed outcome measures three months postintervention.

RESULTS

Generalized linear mixed models (GLMM) analyses indicated that after controlling for sex, cannabis users in the PF + MIT condition significantly reduced DACU and RWCD over time compared to those in the IC condition.

CONCLUSIONS

These findings provide preliminary support for the short-term efficacy of a mobile phone-based intervention in decreasing DACU and RWCD among college cannabis users. Future research should determine whether these reductions in driving behaviors persist past three months.

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.

A Systematic Review and Narrative Synthesis of the Evolution of Adolescent and Young Adult Cannabis Consumption Before and After Legalization

PURPOSE

To systematically review evidence assessing the evolution of cannabis consumption before and after the implementation of non-medical cannabis legislation.

METHODS

MEDLINE, PubMED, PsycINFO, Scopus, and Web of Science were systematically searched for studies that examined change in cannabis consumption before and after nonmedical cannabis legislation. Data were tabulated by study design, levels of consumption, and individual subgroups. Data were analyzed using a narrative synthesis approach, considering study quality.

RESULTS

32 studies were included (11 higher quality and 21 lower quality). 40% of higher quality evidence supported an increase in postlegalization consumption (55% did not report a change and 5% reported a decrease). The increase was most evident for young adults (42% of higher quality evidence) and in the consumption in the past month (37% of higher quality evidence). There was limited supporting evidence for new users having grown in response to legalization. Based on subgroup analysis, the increase in postlegalization consumption was higher among women and those who engage in binge-drinking.

CONCLUSIONS

Higher quality evidence suggests an increase in adolescent past-month consumption of cannabis following legalization in several geographical jurisdictions. Consumption evolution prelegalization and postlegalization differed by age group and for young women and for binge drinkers. Consumption evolution differences suggest a variety of strategies might be required in efforts to lower public health impacts of cannabis consumption following legalization.

A qualitative examination of college students' perceptions of cannabis: insights into the normalization of cannabis use on a college campus

ObjectiveThis study aimed to qualitatively examine how perceptions of cannabis differ among college students in an effort to better understand the changing landscape of cannabis on college campuses. Participants: Forty-six predominantly male (69.9%; M_age = 23.15, SD = 4.11) college students attending a border state university (i.e., a state that has not yet legalized cannabis but borders a state that has). Methods: Participants engaged in facilitated focus group discussions (N = 5) about cannabis-related issues. Results: Thematic analysis uncovered three primary themes and six subthemes. Main themes included: 1) User Heterogeneity and Identity, 2) Relative Benefits and Harms of Cannabis, and 3) Social Position of Cannabis on Campus Culture. Conclusions: Cannabis has quickly integrated into the college social environment, with social stigmatization and identification with cannabis impacting decisions to use. Findings inform existing college health programs on how to approach conversations about cannabis with students.

Marijuana knowledge, confidence in knowledge, and information efficacy as the protective and risk factors of marijuana use among college students

Objective This study explored the relationships between marijuana knowledge, confidence in knowledge, and information efficacy and marijuana use. Furthermore, the effects of the knowledge-related variables were examined on intention to use, resistance efficacy, and intention to vote for legalization. Participants: Undergraduate students (N = 215) were surveyed in Fall 2018. Methods: Data were collected online and analyzed through a series of regression analyses. Results: Higher knowledge was related to less use via higher perceived risk whereas higher confidence in knowledge was related to more use. Marijuana use was related to higher future intention to use, lower resistance self-efficacy, and intention to vote for legalization. Information efficacy was related to intention to vote for legalization only. Conclusions: Students with more knowledge were less likely to use marijuana, whereas students who considered themselves well-informed were more likely to use it. Future intervention efforts will benefit from counteracting students' misplaced confidence in their knowledge.

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.

Changes in Cannabis Consumption Among Emerging Adults in Relation to Policy and Public Health Developments

Background: Rates of cannabis use appear to be highest among emerging adults (EA). Evidence suggests that cannabis smoking, as well as alternate methods of cannabis use (e.g., vaping, edibles) have become a prevalent mode of consumption among this population. Substance use or misuse peaks during emerging adulthood and may be influenced by extreme economic, social and community developments, such as policy changes, public health concerns, and significant global events such as pandemics. For instance, it is highly likely that cannabis consumption trends among at-risk populations were influenced by the legalization of recreational cannabis in Canada, the declaration of the "e-cigarette or vaping product use associated lung injury" or "EVALI" outbreak, and the "COVID-19" pandemic. ObjectivesWe aimed to examine self-reported changes in frequency of cannabis use among EA in Canada (N = 312): pre-legalization, post-legalization; pre-EVALI, post-EVALI; pre-COVID-19, since-COVID-19. ResultsThere was a gradual increase in average frequency of smoking and vaping cannabis across the six different time intervals from the pre-legalization period (2018) to the COVID-19 pandemic period (2020). Males reported higher frequencies of cannabis smoking and vaping compared to females. ConclusionsDespite health concerns and expectations that EVALI and COVID-19 events would lead to decreased consumption, our results suggest an average increase in smoking and vaping cannabis, although the most notable increase was after legalization. There are important sex differences in behavioral factors of cannabis use in EA, though it appears that the "gender-gap" in cannabis consumption is closing. These findings may facilitate the development of intervention programs for policy measures to address cannabis-attributable outcomes in the face of contextual factors that promote use, such as public emergencies or changes in policy landscapes.

The Potential Impact of Recreational Cannabis Legalization on the Prevalence of Cannabis Use Disorder and Psychotic Disorders: A Retrospective Observational Study

OBJECTIVES

The principal objective of our study was to document the short-term impact of the legalization of recreational cannabis on active cannabis use, cannabis use disorder, and various psychotic disorders.

METHODS

We carried out a retrospective observational study of patients who were at least 12 years old and who had visited a psychiatrist in the emergency unit of the Centre hospitalier universitaire de Sherbrooke (CHUS). We included all the consultations of this type over a 5-month period, immediately following the legalization of recreational cannabis in Canada. We then divided our population into an adult (over 18) and teenager group (12 to 17) compared the data to the data from consultations made 2 years earlier, using a generalized linear mixed model.

RESULTS

We examined consultations in patients over 18 years old in prelegalization (n = 1,247) and postlegalization (n = 1,368) groups. We observed a statistically significant increase in the use of cannabis (28.0% to 37.1%; odds ratio [OR] = 1.81 [1.34 to 2.44], P = 0.00011) as well as an increase in diagnoses of active cannabis use disorder (17.7% to 24.3%; OR = 1.53 [1.13 to 2.08], P = 0.0064). The increase in cannabis use disorder was more prominent among patients between 18 and 24 years old (17.3% to 25.9%; OR = 2.27 [1.17 to 4.40], P = 0.015). We observed no statistically significant difference in terms of psychotic disorder diagnoses (27.4% to 29.2%; OR = 1.17 [0.84 to 1.63], P = 0.35)]. Conversely, we identified a greater proportion of patients who had a personality disorder diagnosis in the postlegalization period (39.6% to 44.9%; OR = 1.35 [1.02 to 1.80], P = 0.038). Examination of pediatric (under 18 years old) consultations revealed no statistically significant differences.

CONCLUSION

Although an affirmative conclusion is tentative, the current findings suggest a first link between the legalization of cannabis in Canada and increased diagnoses of cannabis use disorder, as well as cannabis use in general among patients in a university hospital psychiatric emergency department.

Forgoing plans for alcohol and cannabis use in daily life: Examining reasons for nonuse when use was planned in a predominantly white college student sample

BACKGROUND

The reasons for college students to abstain from alcohol and cannabis use on a given day can inform efforts to prevent or intervene in those behaviors. Research on reasons for alcohol nonuse remains in its nascent stages and no study to date has examined reasons for cannabis nonuse on a given day. Here we examine reasons for nonuse among college students after they planned to use alcohol and/or cannabis.

METHODS

College students (N = 341; M_age  = 19.79; 53% women; 74% White) from 3 universities completed 54 days of data collection across which approximately 50% were nonuse days. Each morning, participants indicated whether they planned to use that day; nonuse reasons were assessed the next morning, if applicable. Generalized linear mixed-effects models were used to disentangle within- and between-person effects.

RESULTS

On a given nonuse day (at the within-person level), "work" and "school" were reasons associated with having no plan to use alcohol and "to feel in control" was linked to having no plan to use cannabis. "Did not want to get high" was related to forgoing plans (did not use when originally planned) for alcohol use at the within-person level. At the between-person level, "no desire" was associated with no plans for alcohol or cannabis use and "did not want to get high" was related to no plans for cannabis use. "School" and "could not get" were related to forgoing plans for alcohol and cannabis use, respectively, at the between-person level.

CONCLUSION

An examination of earlier intentions for alcohol and/or cannabis use on nonuse days yielded novel findings on the intention-behavior gap. Reasons for nonuse can inform intervention and prevention strategies (e.g., those involving social norms or just-in-time adaptive efforts) for alcohol and cannabis use on college campuses.

Gender differences in the risk and protective factors of marijuana use among U.S. College students

Gender differences in the risk and protective factors of marijuana use among college students were explored by analyzing online survey responses from 464 undergraduates. Women perceived higher risk and used marijuana less than men, with no gender difference in peer disapproval. In addition, women had higher objective knowledge regarding the health effects of marijuana, although they exhibited lower confidence in their knowledge. In subsequent regression analyses, health knowledge, confidence in knowledge, perceived risk, and peer disapproval predicted women's marijuana use, whereas only confidence in knowledge and perceived risk predicted men's use. These findings can help devise effective intervention strategies.

Cannabis-Induced Hypodopaminergic Anhedonia and Cognitive Decline in Humans: Embracing Putative Induction of Dopamine Homeostasis

Over years, the regular use of cannabis has substantially increased among young adults, as indicated by the rise in cannabis use disorder (CUD), with an estimated prevalence of 8. 3% in the United States. Research shows that exposure to cannabis is associated with hypodopaminergic anhedonia (depression), cognitive decline, poor memory, inattention, impaired learning performance, reduced dopamine brain response-associated emotionality, and increased addiction severity in young adults. The addiction medicine community is increasing concern because of the high content of delta-9-tetrahydrocannabinol (THC) currently found in oral and vaping cannabis products, the cognitive effects of cannabis may become more pronounced in young adults who use these cannabis products. Preliminary research suggests that it is possible to induce 'dopamine homeostasis,' that is, restore dopamine function with dopamine upregulation with the proposed compound and normalize behavior in chronic cannabis users with cannabis-induced hypodopaminergic anhedonia (depression) and cognitive decline. This psychological, neurobiological, anatomical, genetic, and epigenetic research also could provide evidence to use for the development of an appropriate policy regarding the decriminalization of cannabis for recreational use.

Cannabis Legalization and College Mental Health

PURPOSE OF REVIEW

To assess how the changing landscape of marijuana use affects the developing brain and mental health of college students.

RECENT FINDINGS

Legalization of cannabis may facilitate use in the college population, with 38% of college students, whose brains are still maturing, regularly using marijuana products. Earlier and increased use, higher potency, pre-existing issues, and genetic predispositions increase negative outcomes by precipitating or worsening mental illness and ultimately impacting academic success. In the USA, the sharpest increase in cannabis users following legalization has been in the college age population (18-25 years of age). This population is especially vulnerable to the negative impacts and risks associated with cannabis use, including risk for the onset of major psychiatric illness. College mental health practitioners should remain informed about health effects of cannabis use, assess patient use on a regular basis, provide education and be familiar with interventions to reduce harm.

Mode of Marijuana Use among Young Adults: Perceptions, Use Profiles, and Future Use

BACKGROUND

Given changes in marijuana regulations, retail, and products and potential impact on use, we examined young-adult perceptions of different modes of use, the proportion using via different modes (e.g. smoking, vaping, ingesting), and associations with the use levels and stability of use over time.

METHODS

We analyzed baseline and one-year follow-up survey data (Fall 2018-2019) among 3,006 young adults (ages 18-34) across six metropolitan areas (Atlanta, Boston, Minneapolis-St. Paul, Oklahoma City, San Diego, Seattle). Measures included marijuana use frequency and mode, sociodemographics, other substance use, and social influences.

RESULTS

Participants' rated the following modes of use as: least harmful/addictive: topicals, oral pills, joint/bowl; most socially acceptable: joint/bowl, edibles/beverages, vaporized; and most harmful/addictive and least acceptable: wrapped, vaped, or waterpipe/bong with tobacco. Baseline past-month use prevalence was 39.2% (n = 1,178). Most frequent use mode was smoking (joints/bowls/cigar papers; 54.0%), vaping (21.8%), via pipe/bong (15.1%), and ingesting (9.1%). Multinomial logistic regression indicated that participants in states with legalized marijuana retail were at greater odds for using via modes other than smoking; participants more frequently using were at greater odds for using via pipe/bong (vs. smoking) (ps < .001). Regarding most frequent mode across time, most consistent was pipe/bong (53.3%), followed by smoking (49.3%), vaping (44.5%), and ingesting (32.9%). Past-month abstinence at follow-up was most common among those originally ingesting (34.3% abstinent), followed by smoking (23.6%), vaping (18.8%), and pipe/bong (14.8%).

CONCLUSIONS

Ongoing surveillance is needed to understand marijuana use patterns over time across different user groups (particularly by mode) and to inform interventions promoting abstinence.

Pain Profiles among Young Adult Cannabis Users: An Analysis of Antecedent Factors and Distal Outcomes

BACKGROUND

Pain is a primary reason for medical cannabis use among young adults, however little is known about the patterns of pain in this group. This study identified pain profiles among young adult cannabis users and examined related antecedents and distal outcomes.

METHODS

Past 30-day cannabis users aged 18-26, both medical cannabis patients and non-patients, were enrolled in Los Angeles in 2014-2015. A latent class analysis was used to identify pain classes based on history of chronic pain conditions and recent non-minor pain. The study assessed the predictors of membership in pain classes and examined the association of classes with recent mental health characteristics, cannabis use motives and practices.

RESULTS

Three classes were identified: Low pain (56.3%), Multiple pain (27.3%), and Nonspecific pain (16.4%). In adjusted models, lifetime insomnia was associated with membership in Multiple pain and Nonspecific pain classes versus the Low pain class. Medical cannabis patients and Hispanics/Latinos were more likely to belong to the Multiple pain class than the other classes. Regarding recent outcomes, the Multiple pain and Nonspecific pain classes were more likely than the Low pain class to use cannabis to relieve physical pain. Additionally, the Multiple pain class had a higher probability of psychological distress, self-reported medical cannabis use, consuming edibles, and using cannabis to sleep compared to one or both other classes.

CONCLUSION

Findings suggest that young adult cannabis users can be separated into distinct groups with different pain profiles. The Multiple pain profile was associated with medically-oriented cannabis use motives and practices.

Seeking safety: a focus group study of young adults' cannabis-related attitudes, and behavior in a state with legalized recreational cannabis

BACKGROUND

Only July 1, 2017, Nevada became the fifth US state to allow the legal sale of recreational cannabis products for adults ages of 21 and over. This study investigates young adults' cannabis-related attitudes, perceptions, and behaviors in a state where recreational and medical cannabis use was recently legalized.

METHODS

We conducted 8 focus groups stratified by cannabis use (regular users, occasional users, and nonusers) with 32 college students ages 18 to 24. Data were analyzed using the inductive qualitative thematic analysis method.

RESULTS

Four themes emerged during analyses: "sort of legal," "mitigating harm through legalization," "Increasing acceptance," and "seeking safety when purchasing cannabis." Despite their limited knowledge of cannabis regulation, the majority of the participants supported recreational cannabis legalization from a harm reduction perspective. Most participants did not believe that cannabis legalization had affected their use behavior. However, participants, especially cannabis users, perceived that recreational cannabis legalization created a context where cannabis use was legally, socially, and behaviorally "safer" than in an illegal context, even for those below the legal age of sale.

CONCLUSIONS

Most studies focus on the role of perceived health risk on cannabis use. If there are population-level long-term effects of recreational cannabis legalization on use behavior, findings suggest that they will be mediated by the perceived legal, social, and behavioral risk of using cannabis.

Obsessive-Compulsive Symptoms and Cannabis Misuse: The Explanatory Role of Cannabis Use Motives

The purpose of the present investigation was to examine the unique explanatory role of cannabis use motives above the effects of each other, for the relationship between obsessive-compulsive symptomatology and different aspects of cannabis misuse among young adults. The transitional years of young adulthood are characterized by new opportunities for experimentation as well as novel external stressors. Collectively, this makes this developmental epoch a sensitive time for manifestations of cannabis misuse. Methods: Bivariate correlations were conducted to examine the association between obsessive-compulsive symptomatology and risky cannabis use, cannabis use problems, and the average quantity of cannabis used per occasion among a young ethno-racially diverse sample of college students with the past year history of cannabis use (N = 177, 68.95% female, Mage = 21.51, SD = 4.24). Next, multiple mediation analyses were conducted to examine the unique explanatory role of cannabis use motives (e.g., enhancement, conformity, coping, social, and expansion) for the association between the obsessive-compulsive symptoms and cannabis misuse variables which showed significant correlation with these symptoms at the bivariate level. Results: Obsessive-compulsive symptoms were significantly correlated with risky cannabis use (r = .19; p = .02), but not cannabis use problems or the average quantity of cannabis used per occasion. Conducting the multiple mediation for the relationship with the significant bivariate correlation, coping motives significantly explained the relationship between obsessive-compulsive symptoms and risky cannabis use (b = 0.04, SE = 0.02, 95% Bootstrapped CI [0.003, 0.10], Completely Standardized Indirect Effects = 0.07), after controlling for the variance accounted for by problematic alcohol use and smoking status. This indirect effect was not significant after adding anxiety and depressive symptoms as covariates to the model. Conclusions: These findings are discussed in terms of the development of specialized treatments to specifically target cannabis use coping motives among individuals with comorbid obsessive-compulsive disorder and cannabis misuse.

Impact evaluations of drug decriminalisation and legal regulation on drug use, health and social harms: a systematic review

OBJECTIVES

To review the metrics and findings of studies evaluating effects of drug decriminalisation or legal regulation on drug availability, use or related health and social harms globally.

DESIGN

Systematic review with narrative synthesis.

DATA SOURCES

We searched MEDLINE, Embase, PsycINFO, Web of Science and six additional databases for publications from 1 January 1970 through 4 October 2018.

INCLUSION CRITERIA

Peer-reviewed articles or published abstracts in any language with quantitative data on drug availability, use or related health and social harms collected before and after implementation of de jure drug decriminalisation or legal regulation.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers screened titles, abstracts and articles for inclusion. Extraction and quality appraisal (modified Downs and Black checklist) were performed by one reviewer and checked by a second, with discrepancies resolved by a third. We coded study-level outcome measures into metric groupings and categorised the estimated direction of association between the legal change and outcomes of interest.

RESULTS

We screened 4860 titles and 221 full-texts and included 114 articles. Most (n=104, 91.2%) were from the USA, evaluated cannabis reform (n=109, 95.6%) and focussed on legal regulation (n=96, 84.2%). 224 study outcome measures were categorised into 32 metrics, most commonly prevalence (39.5% of studies), frequency (14.0%) or perceived harmfulness (10.5%) of use of the decriminalised or regulated drug; or use of tobacco, alcohol or other drugs (12.3%). Across all substance use metrics, legal reform was most often not associated with changes in use.

CONCLUSIONS

Studies evaluating drug decriminalisation and legal regulation are concentrated in the USA and on cannabis legalisation. Despite the range of outcomes potentially impacted by drug law reform, extant research is narrowly focussed, with a particular emphasis on the prevalence of use. Metrics in drug law reform evaluations require improved alignment with relevant health and social outcomes.

Impacts de la légalisation du cannabis récréatif sur la santé mentale : une recension des écrits

Objectif Cet article présente une recension des écrits sur l’impact de la légalisation du cannabis récréatif sur la santé mentale et s’inscrit dans le contexte des politiques canadiennes récemment adoptées à cet égard.

Méthode Cette recension a été effectuée dans la base de données PubMed en utilisant la combinaison de termes associés au cannabis, à la légalisation et à la santé mentale. Deux évaluateurs indépendants ont ensuite examiné 272 titres et résumés, puis ont conservé 11 articles.

Résultats À la suite de la révision des articles, nous constatons que la plupart des études ciblant la consommation de cannabis décrivent une prévalence croissante d’utilisateurs. Il est à noter qu’aucune étude n’a démontré une diminution de la consommation du cannabis après la légalisation. Parmi les 11 articles retenus, trois évaluent la perception des risques associés au cannabis (avant et après la légalisation). Deux d’entre eux montrent une diminution des risques perçus après la légalisation, alors que le troisième décrit l’inverse. Quelques études ont également analysé l’impact de la légalisation du cannabis sur le nombre de visites à l’urgence générale et elles montrent toutes une augmentation du nombre de visites associées au cannabis. Cela dit, ces résultats sont simplement observationnels et sont à mettre en perspective avec les tendances qui prévalaient déjà avant la légalisation du cannabis.

Conclusion Cette recension des écrits montre qu’il existe un nombre limité d’études concernant l’impact de la légalisation du cannabis récréatif sur les troubles en santé mentale. Il serait donc intéressant de poursuivre les recherches sur ce sujet.

Cannabis-impaired driving and Canadian youth

Acute cannabis use results in inattention, delayed information processing, impaired coordination, and slowed reaction time. Driving simulator studies and epidemiologic analyses suggest that cannabis use increases motor vehicle crash risk. How much concern should we have regarding cannabis associated motor vehicle collision risks among younger drivers? This article summarizes why young, inexperienced drivers may be at a particularly high risk of crashing after using cannabis. We describe the epidemiology of cannabis use among younger drivers, why combining cannabis with alcohol causes significant impairment and why cannabis edibles may pose a heightened risk to traffic safety. We provide recommendations for clinicians counselling younger drivers about cannabis use and driving.

Evaluating the impacts of cannabis legalization: The International Cannabis Policy Study

An increasing number of jurisdictions have legalized non-medical cannabis use, including Canada in October 2018 and several US states starting in 2012. The policy measures implemented within these regulated markets differ with respect to product standards, labelling and warnings, public education, retail policies, marketing, and price/taxation. The International Cannabis Policy Study (ICPS) seeks to evaluate the impacts of these policy measures as well as the broader population-level impact of cannabis legalization using a quasi-experimental research design. The objective of this paper is to describe the ICPS conceptual framework, methods, and baseline estimates of cannabis use. The ICPS is a prospective cohort survey conducted with national samples of 16-65-year-olds in Canada and the US. Data are collected via an online survey using the Nielsen Consumer Insights Global Panel. Primary survey domains include: prevalence and patterns of cannabis use; purchasing and price; consumption and product types; commercial retail environment; problematic use and risk behaviours; cannabis knowledge and risk perceptions; and policy-relevant outcomes including exposure to health warnings, public educational campaigns, and advertising and promotion. The first annual wave was conducted in Aug-Oct 2018 with 27,169 respondents in three geographic 'conditions': Canada (n = 10,057), US states that had legalized non-medical cannabis (n = 7,398) and US states in which non-medical cannabis was prohibited (n = 9,714). The ICPS indicates substantial differences in cannabis use in jurisdictions with different regulatory frameworks for cannabis. Future waves of the study will examine changes over time in cannabis use and its effects associated with legalization in Canada and additional US states.

From prohibition to regulation: A comparative analysis of the emergence and related outcomes of new legal cannabis policy models (Colorado, Washington State and Uruguay)

An effective approach to drug regulation is a growing concern. Since 2012, 10 US States and Uruguay have taken the step to revoke prohibition and legalize the recreational cannabis market. Based on the findings from a study ('Cannalex') carried out in 2015-2017 in Colorado, Washington and Uruguay by the French Monitoring Centre for Drugs and Drug Addiction (OFDT) and the Institute of Security and Justice (INHESJ), relying on a hundred of in-depth interviews analyzed in line with the existing official statistics and studies, this paper shows heterogeneous policy-making models and contexts for reform. It also examines the early outcomes of the cannabis policy change. A mixed picture is emerging from the regulatory regimes currently implemented. This paper discusses the reform processes and their early outcomes, with a specific focus on the less documented area: the political processes that led to legalizing cannabis, analyzed with qualitative data. It argues that the different outcomes reported across Colorado, Washington and Uruguay are framed by the regulatory options that were taken, depending on specific dynamics of reform. The discussion focuses on some hot topics raised by the effective regulations, stressing that the array of cannabis regulatory options is a public debate that has just begun.

International Perspectives on the Implications of Cannabis Legalization: A Systematic Review & Thematic Analysis

The legality, recreational and medical use of cannabis varies widely by country and region but remains largely prohibited internationally. In October 2018, Canada legalized the recreational use of cannabis—a move many viewed as controversial. Proponents of legalization have emphasized the potential to eradicate the marijuana black market, improve quality and safety control, increase tax revenues, improve the availability of medical cannabis, and lower gang-related drug violence. Conversely, opponents of legalization have stressed concerns about cannabis’ addictive potential, second-hand cannabis exposure, potential exacerbation of underlying and established mental illnesses, as well as alterations in perception that affect safety, particularly driving. This systematic review synthesizes recent international literature on the clinical and public health implications of cannabis legalization.

Using Classification Trees to Examine Predictors of Marijuana Use Among a Wide Range of Variables

Background: Young adults have elevated risk for negative marijuana use-related outcomes, and there is heterogeneity among users. Identifying risk factors for marijuana user status will improve understanding of different populations of users, which may inform prediction of individuals most likely to experience negative outcomes. Objectives: To identify predictors of marijuana use initiation in young adults. We simultaneously examined a broad range of potential predictors and all their possible interactions, including constructs that have not been previously studied in substance use initiation research. Methods: Data were repeated cross-sectional survey responses from college students in Colorado (N = 4052, 77% White, 61% female, mean age = 22.77). Measures came from the National College Health Assessment, which assesses numerous health and behavioral constructs. We used recursive partitioning and random forest models to identify predictors of ever having used marijuana out of 206 variables. Results: Classification trees identified engagement in increased alcohol use and sexual behavior as salient correlates of marijuana use initiation. Parsimonious recursive partitioning trees explained a substantial amount of variability in marijuana user status (39% in the full model and 24% when alcohol variables were excluded). Random forest models predicted user status with 74.11% and 66.91% accuracy in the full model and when alcohol variables were excluded, respectively. Conclusions: Results support the use of exploratory analyses to explain heterogeneity among marijuana users and non-users. Since engagement in other health-risk behaviors were salient predictors of use initiation, prevention efforts to reduce harm from marijuana use may benefit from targeting risk factors for health-risk behaviors in general.