International differences in patterns of cannabis use among youth: Prevalence, perceptions of harm, and driving under the influence in Canada, England & United States

Driving Under the Influence of Alcohol, Cannabis, and Delta-8 THC: Perceived Likelihood, Risk Perceptions, and Behaviors

Driving under the influence (DUI) of alcohol or cannabis poses public health risks. Little is known about DUI of Delta-8 THC, a newer cannabis product. Using 2022 survey data among 189 U.S. adults ages 18-25 (58.73% male, 59.26% non-Hispanic White), multivariable logistic regression examined substance-specific (alcohol, cannabis, Delta-8) DUI perceived likelihood and risk in relation to past-year DUI among those with past-year use of each. Overall, 72.49% reported past-year alcohol use, 50.53% cannabis, and 22.46% Delta-8. Among those reporting past-year use of each respective substance, 33.58% reported DUI of alcohol, 32.63% cannabis, and 57.14% Delta-8. On average, participants had the same DUI perceived likelihood ("somewhat unlikely") across substances and perceived alcohol DUI as riskiest. Higher alcohol DUI perceived likelihood and lower perceived risk were associated with alcohol-related DUI. Greater cannabis-related perceived likelihood (but not risk) was associated with cannabis-related DUI. Neither Delta-8 DUI perceived likelihood nor risk were associated with Delta-8 DUI. In sum, perceived DUI likelihood for alcohol, cannabis, or Delta-8 tended to be similar. Among those with past-year use of each, the proportion of DUI was highest for Delta-8. Interventions should target DUI-related perceived likelihood and promote protective behavioral strategies that reduce substance-specific DUI risk.

Driving after substance use in Rhode Island adolescents: A cross-sectional analysis of surveillance data

OBJECTIVE

Existing literature on driving under the influence during adolescence is sparse, especially for driving after the use of non-medical prescription drugs (DAP). This study examines the prevalence of driving after use of alcohol (DAA), cannabis (DAC), and DAP, and examines the role of several potential risk and protective factors.

METHODS

This was a secondary analysis of the 2022 Rhode Island Study Survey, a cross-sectional survey of middle and high school students. Separate multivariable regressions were conducted for each outcome among lifetime users for each substance, controlling for current substance use, individual-, perceived parental-, and perceived friend-substance use risk perception, age, sexual/gender minority (SGM) status, race, ethnicity, school level, and town poverty level.

RESULTS

Among lifetime users of alcohol (n = 3849), cannabis (n = 2289), and non-medical prescription drugs (n = 611), the prevalence of DAA, DAC, and DAP was 4.9, 14.3, and 16.9%, respectively. Current substance use, high individual risk perception, being nonwhite, and being Hispanic were risk factors for DAA while perceiving parent's risk perception as negative and being heterosexual cisgender-female were protective. Current substance use, negative individual risk perception, and being nonwhite were risk factors for DAC while perceiving parent's risk perception as negative and being in high school were protective. Current substance use and older age were risk factors for DAP while perceiving parent's risk perception as negative and perceiving friend's risk perception as negative were protective.

CONCLUSIONS

Driving under the influence is a concern among adolescent substance users. Current substance use and perceived parental risk perception as negative are common risks and protective factors, respectively. Findings suggest substance-specific, heterogeneous interventions are needed. For example, interventions focusing on peer perceptions are most relevant for DAP, while shifting personal perceptions of harm are most relevant for DAC.

Results of a randomized controlled trial of the cannabis eCHECKUP TO GO personalized normative feedback intervention on reducing cannabis use, cannabis consequences, and descriptive norms

BACKGROUND

The prevalence of cannabis use disorder and its negative consequences among young adults has highlighted the need for prevention and early intervention programs. However, low treatment prevalence persists due to factors such as lack of perceived need, concerns about stigma, and limited access to treatment. To address these barriers, web-based cannabis interventions have been developed, but their efficacy remain limited. This study aims to evaluate the cross-site efficacy of the Cannabis eCHECKUP TO GO program, a web-based Personalized Normative Feedback and Protective Behavioral Strategies intervention for reducing cannabis use frequency and consequences in college students with willingness to change.

METHODS

Participants were 781 students from three universities (two in Canada, one in the US) who reported using cannabis in the past month and expressed interest in reducing or engaging in safer cannabis use. The study randomly assigned them to either an experimental group that received personalized normative feedback or a control group that received information on healthy stress management. The study collected follow-up data 4 weeks after the initial intervention and measured participants' frequency of cannabis use, number of cannabis consequences, descriptive and injunctive norms at both time points.

RESULTS

The results showed no significant reductions in cannabis use or negative consequences of use. However, students who received personalized normative feedback experienced a significant reduction in descriptive norms related to cannabis use, to be more in line with actual use.

CONCLUSION

This study suggests that more targeted interventions may be necessary for university students who are already using and seeking help to reduce their use.

Adolescents' Cannabis Knowledge and Risk Perception: A Systematic Review

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

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.

Perceptions of cannabis use risk to mental health among youth in Canada, England and the United States from 2017 to 2021

BACKGROUND

There is little research examining perceptions of cannabis use risk to mental health in countries with differing cannabis regulations. This study therefore examines such perceptions among youth between 2017 and 2021 in Canada (non-medical cannabis legalized in October 2018), England (highly-restricted medical cannabis legalized November 2018), and the US (non-medical cannabis legal in some states).

METHODS

Seven repeat cross-sectional online surveys were conducted between July 2017 to August 2021 among youth aged 16-19 in Canada (N=29,420), England (N=28,155), and the US (N=32,974). Logistic regression models, stratified by country, were used to examine perceptions of cannabis use risk to mental health over time, adjusting for age group, sex, race/ethnicity, cannabis use and, for the US only, state-level cannabis legalization.

RESULTS

Perceptions that cannabis use posed "no risk" to mental health decreased between July 2017 and August 2021 in Canada (6.1-4.4%; AOR=0.64, 95% CI=0.52-0.78) and the US (14.0-11.3%; AOR=0.74, 0.65-0.84) but not England (3.7-4.5%; AOR=1.21, 0.97-1.52). No significant changes were observed from immediately before (August 2018) to after (August 2019) legalization of non-medical cannabis in Canada (AOR=0.99, 0.83-1.20) or highly-restricted medical cannabis in England (AOR=0.90, 0.70-1.17). In the US, perceptions of "no risk" were more likely in states where cannabis use was illegal (15.0%) compared with legal non-medical (12.2%) (AOR=0.68, 0.63-0.74).

CONCLUSION

There were modest decreases in perceptions that cannabis use poses no risk to mental health in Canada and the US between 2017 and 2021 but no clear association with cannabis legalization status.

Recreational Cannabis Legislation: substance use and impaired driving among Canadian rural and urban postsecondary students

BACKGROUND

Investigation of cannabis use trends among emerging adults (EA, aged between 18 and 24 years) following 2018 Canadian Recreational Cannabis Legislation (RCL) is critical. EAs report the heaviest cannabis use in Canada and are particularly vulnerable to the onset of problematic substance use.

OBJECTIVES

To describe and compare post-RCL use of cannabis and other state-altering substances, as well as the prevalence of impaired driving, among EA postsecondary students in both rural and urban settings, studying on one of five campuses in either Manitoba, Ontario, or Quebec.

METHODS

For this quantitative cross-sectional study, a self-report survey was administered to 1496 EA postsecondary students in the months following RCL (2018-2019). Multiple logistic regression analyses were conducted to explore the influence of provincial and urban/rural living contexts on recreational cannabis use, other state-altering substance use and impaired driving behaviours, adjusting for sociodemographic variables.

RESULTS

Statistically significant differences were observed between cohorts in almost all measures. Quebec students were more likely to have consumed cannabis during their lifetime (AOR = 1.41, 95% CI [1.05, 1.90]) than all other cohorts. Rural cohorts all had greater odds of reporting consumption of cannabis during the previous year compared to urban cohorts (AOR = 1.32, 95% CI [1.04, 1.67]). However, the relation between cannabis use in the last month and operating a motor vehicle after using cannabis (lifetime and past month) and living context differed between subjects in Quebec and those in the two other provinces. Quebec's students having lived mostly in urban contexts had greater odds of using cannabis in the past month and operating a motor vehicle after using cannabis (lifetime and past month) than those in rural contexts; the opposite was observed in Manitoba and Ontario. Differing interprovincial prohibitive/permissive legislation and licit cannabis infrastructure appeared to have little impact on post-RCL substance use.

CONCLUSIONS

In Manitoba and in Ontario, rural/urban living context seems to better predict substance use and related road-safety practices, suggesting these trends supersede permissive/prohibitive provincial legislation and licit cannabis-related infrastructures. Further investigation into sociodemographic factors influencing state-altering substance use and impaired driving, and maintaining tailored cannabis misuse prevention campaigns, is warranted on Canadian campuses.

Effects of Cannabis Legalization on Road Safety: A Literature Review

BACKGROUND

Legalizing medical and recreational cannabis and decriminalizing this substance may have unanticipated effects on traffic safety. The present study aimed to assess the impact of cannabis legalization on traffic accidents.

METHODS

A systematic review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration of the articles included in the Web of Science (WoS) and Scopus databases. The number of papers included in the review was 29.

RESULTS

The results show that in 15 papers, there is a relationship between the legalization of medical and/or recreational cannabis and the number of traffic accidents, while in 5 papers, no such relationship is observed. In addition, nine articles indicate a greater number of risk behaviors related to driving after consumption, identifying young, male, and alcohol consumption together with cannabis as the risk profile.

CONCLUSIONS

It can be concluded that the legalization of medical and/or recreational cannabis has negative effects on road safety when considering the number of jobs that affect the number of fatalities.

Emerging Adult Perceptions of Cannabis Consumption Post-Legalization: Considering Age and Sex Differences

PURPOSE

Increased access to legalized non-medical cannabis has led to growing concern over the potential adverse health impacts of cannabis consumption among youth and emerging adults. This study explored emerging adult perceptions of cannabis consumption and if perceptions changed based on the age and sex of the cannabis consumer.

METHODS

Canadian emerging adults between the ages of 18 and 25 years (N = 1,424, Mean = 21.23) were randomly assigned to one of six vignettes that varied by age (14 years, 21 years, and 28 years) or sex (male, female) of the cannabis consumer. Participants were asked to rate seven single-item measures on perceived dangerousness, problematic consumption, negative impacts, and level of disapproval related to the vignette character's almost daily cannabis consumption.

RESULTS

The results of seven 2 × 3 factorial analyses of variance revealed a main effect of age on six of seven items, no main effects of sex, and no interactions. Except for social life, participants noted significant differences in harms of cannabis consumption by 14-year-olds, compared to 21-year-olds and 28-year-olds. There were no significant differences in overall perceived dangerousness, problematic consumption, or impact on mental or cognitive health between 21-year-olds and 28-year-olds. Participants perceived cannabis consumption by a 21-year-old to be more harmful to brain development and reported greater disapproval than consumption by a 28-year-old.

DISCUSSION

Emerging adults may appreciate the impacts of cannabis consumption within their age cohort on brain development and perceive greater risks for youth. Further education should focus on the potential cognitive and mental health impacts of cannabis in emerging adults.

Digital interventions for substance use disorders in young people: rapid review

BACKGROUND

Young people are disproportionately more likely than other age groups to use substances. The rise in substance use and related harms, including overdose, during the Covid-19 pandemic has created a critical need for more innovative and accessible substance use interventions. Digital interventions have shown effectiveness and can provide more engaging, less stigmatizing, and accessible interventions that meet the needs of young people. This review provides an overview of recent literature on the nature of recently published digital interventions for young people in terms of technologies used, substances targeted, intended outcomes and theoretical or therapeutic models employed.

METHODS

Rapid review methodology was used to identify and assess the literature on digital interventions for young people. An initial keyword search was conducted using MEDLINE the Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment Database (HTA) and PROSPERO for the years 2015-2020, and later updated to December 2021. Following a title/abstract and full-text screening of articles, and consensus decision on study inclusion, the data extraction process proceeded using an extraction grid developed for the study. Data synthesis relied on an adapted conceptual framework by Stockings, et al. that involved a three-level treatment spectrum for youth substance use (prevention, early intervention, and treatment) for any type of substance.

RESULTS

In total, the review identified 43 articles describing 39 different digital interventions. Most were early interventions (n = 28), followed by prevention interventions (n = 6) and treatment interventions (n = 5). The identified digital technologies included web-based (n = 14), game-based (n = 10), mobile-based (n = 7), and computer-based (n = 5) technologies, and virtual reality (n = 3). Most interventions targeted alcohol use (n = 20) followed by tobacco/nicotine (n = 5), cannabis (n = 2), opioids (n = 2), ketamine (1) and multiple, or any substances (n = 9). Most interventions used a personalized or normative feedback approach and aimed to effect behaviour change as the intended outcome. Interestingly, a harm reduction approach guided only one of the 39 interventions.

CONCLUSIONS

While web-based interventions represented the most common type of technology, more recently developed immersive and interactive technologies such as virtual reality and game-based interventions call for further exploration. Digital interventions focused mainly on alcohol use, reflecting less concern for tobacco, cannabis, co-occurring substance use, and illicit drug use. Specifically, the recent exacerbation in the opioid crisis throughout North American underlines the urgent need for more prevention-oriented digital interventions for opioid use. The uptake of digital interventions among youth also depends on the incorporation of harm reduction approaches.

Driving under the influence of cannabis: perceptions from Canadian youth

BACKGROUND

Cannabis legalization is intended to protect the public from potential harm by restricting access and promoting greater awareness of cannabis-related risks. Youth are at a greater risk for experiencing road-related harms due to their own or others' use of cannabis. This qualitative research explored youths' perceptions about cannabis and road safety.

METHODS

A qualitative study using focus groups (FG) was conducted with youth (age 13-18) and young adults (age 19-25) who resided in Newfoundland and Labrador. Using semi-structured interview questions, the facilitator asked participants to share their opinions about cannabis and road safety. All sessions were hosted virtually using Zoom with recruitment until saturation was met. All sessions were audio recorded, de-identified, and transcribed. Analysis utilized an inductive thematic approach informed by Braun and Clarke's (2006) method and inductive coding was facilitated using NVivo.

RESULTS

Six youth (n = 38) and five young adult (n = 53) FG were conducted. Five prominent themes emerged throughout discussions across both age groups including: a) normalization of driving under the influence of cannabis, b) knowledge and awareness, c) perceptions of risk, d) modes of transportation, and e) detection. Variation in perceptions appeared to be influenced by lack of awareness of the impact of cannabis on driving ability, residence in urban versus rural locations, type of vehicle driven (e.g., car vs. off-road vehicles), and gender.

CONCLUSION

The themes uncovered from this research will help inform future enhancement of cannabis policy to ensure the safety of all citizens. These findings will also support the inclusion of youth-focused education that will equip youth with informed decision-making strategies regarding road safety. Furthermore, these findings can be utilized to inform the refinement of cannabis driving policies to ensure the safety of all citizens on or off the road.

Differences between adults who smoke cigarettes daily and do and do not co-use cannabis: Findings from the 2020 ITC four country smoking and vaping survey

BACKGROUND

Little is known about population-level differences between adults who exclusively smoke cigarettes and those who smoke cigarettes and also use cannabis (co-consumers). Thus, this study describes differences on sociodemographic, cigarette-dependence, health and behavioral variables, and risk perceptions associated with smoking cannabis.

METHODS

This cross-sectional study included 6941 respondents from the 2020 ITC Four Country Smoking and Vaping Survey (US, Canada, Australia, England). Adult daily cigarette smokers were included and categorized as: cigarette-only smokers (never used cannabis/previously used cannabis, but not in the past 12 months, n = 4857); occasional co-consumers (cannabis use in the past 12 months, but < weekly use, n = 739); or regular co-consumers (use cannabis ≥ weekly, n = 1345). All outcomes were self-reported. Regression models were conducted on weighted data.

RESULTS

Overall, 19.9 % of respondents reported regular cannabis co-use and 10.1 % reported occasional co-use. Regular co-use was highest in Canada (27.2 %), followed by the US (24.4 %), England (12.7 %) and Australia (12.3 %). Compared to cigarette-only smokers, regular co-consumers were more likely to be male and report chest/breathing problems (p < 0.001). All co-consumers were more likely to be younger, have lower income, be experiencing financial stress, reside in Canada, have depressive symptoms, use alcohol more frequently and binge drink, use other tobacco/nicotine products, and perceive smoking cannabis as low health risk and less harmful than smoking cigarettes (all p < 0.001). Cigarette dependence measures were similar between co-consumers and cigarette-only smokers (all p ≥ 0.05).

CONCLUSIONS

Although there were no differences on cigarette dependence measures between daily cigarette smokers who do and do not use cannabis, there are several other risk factors that may affect tobacco use and abstinence among co-consumers (e.g., greater depression, high-risk alcohol consumption). Thus, tobacco cessation treatment may require multi-pronged strategies to address other health behaviors. Continued surveillance is needed to determine the nature and health implications of co-use considering changing policies, markets, and products.

Cannabis Adaptation During and After Alcohol Ignition Interlock Device Installation: A Longitudinal Study

OBJECTIVE

A common intervention to prevent alcohol-impaired driving are alcohol ignition interlock devices (IIDs), which prevent drivers with a blood alcohol concentration greater than .025% from starting the car. These devices force drivers to adapt their drinking to accommodate the device. Prior studies indicated a transfer of risk as some drivers with an IID may increase cannabis use as they decrease alcohol use. This study examines whether this increase in cannabis use persists after IID removal when alcohol use reverts to pre-IID levels.

METHOD

The data are from the Managing Heavy Drinking (MHD) study of drivers in New York State. The MHD is a comprehensive three-wave study of drivers convicted of driving under the influence from 2015 to 2020. Participants (N = 189) completed all waves, and provided oral fluid/blood and hair samples to measure cannabis and alcohol use, respectively. Mixed between-within analysis of variance was conducted to assess cannabis use at IID installation (Time 1), removal (Time 2), and at 6-month follow-up (Time 3).

RESULTS

In aggregate, participants increased their cannabis use over the course of the study. Drivers who decreased their alcohol use while the IID was installed on their car significantly increased their cannabis use while the IID was in place and further increased cannabis use after the device's removal.

CONCLUSIONS

IIDs are efficacious in preventing alcohol-impaired driving. However, in some cases, they may have the unintended effect of increasing other substance use. The current study outlines the need for supplemental treatment interventions while on IID to prevent a transfer of risk to other substances, or polysubstance use after the device is removed.

Effort-based decision making and self-reported apathy in frequent cannabis users and healthy controls: A replication and extension

INTRODUCTION

Amotivational syndrome is a term used to refer to lack of motivation and passive personality related to chronic cannabis use. Given mixed findings, the current study aimed to replicate and extend previous research on frequent cannabis use, motivated behavior, and self-reported apathy.

METHOD

Cannabis users (on average, ≥3 days/week of cannabis use over the past year), and healthy controls (≤1 day/month of cannabis use over the past year) completed the Apathy Evaluation Scale (AES), and the Effort Expenditure for Rewards Task (EEfRT). Repeated measures analysis of covariance was used to 1) examine the effects of group, reward magnitude, probability, and their interaction on hard task selections on the EEfRT, and 2) examine between-group differences on the AES, controlling for alcohol use and depressive symptoms.

RESULTS

There were significant main effects of reward magnitude, probability, and an interaction between reward magnitude and probability on hard task selection (p's < 0.05). Specifically, as reward magnitude and probability of winning the reward increased, participants were more likely to select hard tasks on the EEfRT. Relative to healthy controls, cannabis users were significantly more likely to select hard tasks on the EEfRT (F(1,56) = 6.49, p = 0.014, η_p² = 0.10). When controlling for alcohol use and depressive symptoms, no significant group differences in self-reported apathy were present (p = 0.46).

CONCLUSIONS

Cannabis users exhibit a greater likelihood of exerting more effort for reward, suggesting enhanced motivation relative to healthy controls. Thus, the current results do not support amotivational syndrome in adult frequent cannabis users. Despite some harms of long-term cannabis use, amotivation may not be among them.

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.

Trends in cannabis-related attitudes and behaviors among cannabis-using adolescent and young adult outpatients following medical cannabis legalization in Massachusetts

Background: Among youth already using cannabis, legalization of medical cannabis may influence cannabis-related attitudes and behaviors, including increasing access through use of someone else's medical cannabis (diversion). Objective: To examine cannabis-related attitudes and behaviors (including diverted cannabis use) in cannabis-using youth in the four years following medical cannabis legalization. Additionally, we investigated characteristics of youth who used vs. did not use diverted medical cannabis. Methods: Data were collected in Boston from 2013 (when medical cannabis legislation took effect in Massachusetts) through 2016 (when recreational cannabis use became legal in Massachusetts). Cannabis-using youth (age 13-24) presenting to an outpatient adolescent substance use treatment program (ASUTP) or recruited for an adolescent medicine clinic study (AMCS) completed a confidential survey on demographic characteristics and cannabis use behaviors and attitudes. We used multiple logistic regression to analyze changes in attitudes and behaviors over three years versus the reference year (2013), controlling for demographics. We used chi-square to compare characteristics of youth reporting use of diverted medical cannabis versus those not. Results: The sample included 273 cannabis-using youth (ASUTP n = 203, AMCS n = 70; 2013 n = 67, 2014 n = 67, 2015 n = 77, 2016 n = 62). Mean ± SD age was 18.2 ± 2.5 years, 32% were female, 58% were White non-Hispanic, and 70% had college-graduate parents. In 2013, most youth reported that cannabis was easy to obtain (97.9%), and that occasional cannabis use had "no" or "slight" risk of harm (89.4%), with little change across years. In 2016, 44% of youth reported using someone else's medical cannabis, versus 15% in 2013 (aOR 4.66, 95% CI 1.81, 11.95). Youth using diverted medical cannabis had higher likelihood of reporting riding with a driver, or driving themselves, after cannabis use (both p < .01). Conclusion: Among at-risk youth in Massachusetts, use of diverted medical cannabis increased after medical cannabis legalization, and those using diverted medical cannabis reported higher risk for cannabis-related traffic injury.

Sports- and Physical Activity-Related Concussions, Binge Drinking and Marijuana Use among Adolescents: The Mediating Role of Depression and Suicidal Ideation

BACKGROUND

Although past studies have examined the adverse impact of sports- and physical activity-related concussions (SPACs) on health and mental health outcomes, there is a dearth of research investigating the association between SPACs and binge drinking and marijuana use.

OBJECTIVE

The objective of this study is to examine the cross-sectional association between SPACs and binge drinking and marijuana use among adolescents and whether symptoms of depression and suicidal ideation mediate this association.

METHODS

Data for this study came from the 2017 and 2019 National Youth Risk Behavior Survey. An analytic sample of 17,175 adolescents aged 14-18 years (50.2% male) was analyzed using binary logistic regression.

RESULTS

Of the 17,175 adolescents, 13.7% engaged in binge drinking and 19.3% used marijuana 30 days preceding the survey date. Approximately one in seven (14.1%) adolescents had SPACs during the past year. Upon controlling for the effects of other factors, adolescents who had SPACs had 1.74 times higher odds of engaging in binge drinking (AOR = 1.74, p<.001, 95% CI = 1.47-2.06) and 1.42 times higher odds of using marijuana (AOR = 1.42, p<.001, 95% CI = 1.24-1.62) than those who did not have SPACs. Symptoms of depression and suicidal ideation explained 12% of the association between SPACs and binge drinking, and 19% of the association between SPACs and marijuana use.

CONCLUSIONS

Understanding the association between SPACs and substance use and mental health could contribute to early identification of adolescents who may engage in substance use.

Patterns of Cannabis Use among Canadian Youth over Time; Examining Changes in Mode and Frequency Using Latent Transition Analysis

Background: Historically substance use literature has focused on smoking as the main mode of cannabis consumption, so there are knowledge gaps surrounding current understanding of edibles and vaping. These alternative modes of cannabis use are already common among Canadian youth; however, little is known about how these cannabis use patterns change over time. Methods: This study examined the mode (smoking, eating/drinking, vaping) and frequency of cannabis use among a large sample of Canadian youth who participated in 2017-2018 and 2018-2019 data collection waves of the COMPASS study. Using latent transition analysis, this sample consisting of 18,824 youth in grades 9-12 were categorized into cannabis use classes stratified by sex, and their transition between these classes over the one-year period was examined. Results: Three cannabis use classes were identified (occasional multimode, regular multimode, and smoking) alongside one nonuse class. Among youth who reported cannabis use at baseline, transitioning to a multimode group, and/or increasing frequency of multimode use was likely over the one-year period. Conclusions: These findings may highlight a key leverage point for harm-reduction strategies which aim to prevent cannabis related harms associated with high frequency use.

Lower-Risk Cannabis Use Guidelines (LRCUG) for reducing health harms from non-medical cannabis use: A comprehensive evidence and recommendations update

BACKGROUND

Cannabis use is common, especially among young people, and is associated with risks for various health harms. Some jurisdictions have recently moved to legalization/regulation pursuing public health goals. Evidence-based 'Lower Risk Cannabis Use Guidelines' (LRCUG) and recommendations were previously developed to reduce modifiable risk factors of cannabis-related adverse health outcomes; related evidence has evolved substantially since. We aimed to review new scientific evidence and to develop comprehensively up-to-date LRCUG, including their recommendations, on this evidence basis.

METHODS

Targeted searches for literature (since 2016) on main risk factors for cannabis-related adverse health outcomes modifiable by the user-individual were conducted. Topical areas were informed by previous LRCUG content and expanded upon current evidence. Searches preferentially focused on systematic reviews, supplemented by key individual studies. The review results were evidence-graded, topically organized and narratively summarized; recommendations were developed through an iterative scientific expert consensus development process.

RESULTS

A substantial body of modifiable risk factors for cannabis use-related health harms were identified with varying evidence quality. Twelve substantive recommendation clusters and three precautionary statements were developed. In general, current evidence suggests that individuals can substantially reduce their risk for adverse health outcomes if they delay the onset of cannabis use until after adolescence, avoid the use of high-potency (THC) cannabis products and high-frequency/-intensity of use, and refrain from smoking-routes for administration. While young people are particularly vulnerable to cannabis-related harms, other sub-groups (e.g., pregnant women, drivers, older adults, those with co-morbidities) are advised to exercise particular caution with use-related risks. Legal/regulated cannabis products should be used where possible.

CONCLUSIONS

Cannabis use can result in adverse health outcomes, mostly among sub-groups with higher-risk use. Reducing the risk factors identified can help to reduce health harms from use. The LRCUG offer one targeted intervention component within a comprehensive public health approach for cannabis use. They require effective audience-tailoring and dissemination, regular updating as new evidence become available, and should be evaluated for their impact.

Cannabis and cannabidiol use among autistic and non-autistic adults in the UK: a propensity score-matched analysis

OBJECTIVES

To assess whether autistic and non-autistic adults differ in their cannabis and cannabidiol (CBD) use, their perceptions of cannabinoid products and their cannabinoid-related support-seeking behaviours.

DESIGN

Cross-sectional survey.

PARTICIPANTS

Respondents to an online survey, who self-reported an autism-spectrum disorder diagnosis (autistic participants) or no issues relating to autism (controls). Exclusion criteria were: related/subclinical issues relating to autism, non-UK residence, under 16 years old. Propensity score matching was used to match autistic participants and controls on age, gender and ethnicity. The full-sample analysis included 269 participants and the propensity-matched sample analysis included 166 participants. Propensity-matched analysis was used for primary analysis and was considered robust if supported by triangulation with full-sample analysis.

RESULTS

Autistic participants were more likely to have used CBD in the past 12 months compared with controls (OR=3.52, 95% CI 1.57 to 7.87, p=0.002). They used CBD on more days in the past 12 months (M=34, SD=93) compared with controls (M=17, SD=69, p=0.002). Autistic participants reported trusting the news and doctors less as sources of cannabinoid-related information than controls (p=0.024 and p=0.003, respectively). Autistic participants endorsed the following barriers to cannabinoid-related support seeking more than controls: 'worrying they won't understand me' (OR=3.25, 95% CI 1.67 to 6.33, p<0.001), 'going somewhere unfamiliar' (OR=5.29, 95% CI 2.62 to 10.67, p<0.001) and 'being in a crowded or chaotic place' (OR=9.79, 95% CI 4.18 to 22.89, p<0.001).

CONCLUSION

Results indicate a higher prevalence and frequency of CBD use, but not cannabis use, among autistic individuals compared with controls. Findings also suggest appropriate methods to disseminate cannabinoid-related support to autistic individuals, and indicate differences in the potential barriers autistic and non-autistic individuals may face when seeking cannabinoid-related support.

Driving under the influence of cannabis risk perceptions and behaviour: A population-based study in Ontario, Canada

Driving under the influence of cannabis (DUIC) is detrimental to road safety. Risk perception is a strong determinant of DUIC behaviour, yet little is known about the factors influencing DUIC risk perception in the general population. The objective of this study was to identify factors associated with risk perceptions of motor vehicle collision and legal consequences due to DUIC and examine whether these perceptions were associated with DUIC behaviour. Data were derived from the 2017 CAMH Monitor, a cross-sectional telephone survey of adults aged 18+ years in Ontario, Canada (n = 1813). Multivariable logistic regression analyses were performed. Approximately 90% of adults overall agreed that DUIC increases motor vehicle collision risk compared to 55% of those reporting past-year DUIC. Being male, less educated, and using cannabis at least monthly were associated with disagreeing that DUIC increases motor vehicle collision risk. Being male, young, and using cannabis at least monthly were associated with agreeing that DUIC is safer than driving under the influence of alcohol (DUIA). Being male and using cannabis less than monthly were associated with agreeing that the chances of getting caught for DUIC are higher than DUIA. Safety but not legal risk perceptions were associated with DUIC behaviour among cannabis-using drivers. Cannabis legalization provides a timely opportunity for DUIC prevention strategies. This study suggests that policymakers should target male cannabis users and highlight the safety risks of DUIC. Further research is needed to assess the effectiveness of prevention measures and the impact of cannabis legalization on DUIC perceptions and behaviour.

Cigarette dependence is more prevalent and increasing among US adolescents and adults who use cannabis, 2002-2019

SIGNIFICANCE

Cannabis use is increasing among cigarette smokers. If cannabis use is associated with cigarette dependence, a barrier to smoking cessation, this could have public health implications for tobacco control. The current study estimated the prevalence of cigarette dependence among US individuals who smoke cigarettes by cannabis use status, and investigated trends in cigarette dependence from 2002 to 2019 among cigarette smokers by cannabis use status and cigarette consumption (ie, cigarettes per day, CPD).

METHODS

Data were drawn from the 2002-2019 annual National Survey on Drug Use and Health and included US individuals aged 12+ years who used cigarettes at least once in the past month (n=231 572). Logistic regression was used to estimate the prevalence of cigarette dependence, measured as time to first cigarette <30 min, by past-month cannabis use (no use, non-daily use, daily use), and to estimate trends in cigarette dependence from 2002 to 2019 overall and stratified by cannabis use and smoking level (light, 1-5 CPD; moderate, 6-15 CPD; heavy, 16+ CPD).

RESULTS

Across all levels of cigarette use, cigarette dependence was significantly more common among individuals with daily cannabis use compared with those with non-daily or no cannabis use. From 2002 to 2019, cigarette dependence increased among cigarette smokers with non-daily cannabis use, and among light and moderate cigarette smokers with no cannabis use.

CONCLUSIONS

US individuals who use both cigarettes and cannabis report a higher prevalence of cigarette dependence relative to individuals who use cigarettes and do not use cannabis at virtually all levels of cigarette consumption. Further, cigarette dependence is increasing in the USA both among those who use and do not use cannabis. Given the increase in cannabis use among those using cigarettes, efforts to elucidate the nature of the association between cannabis and cigarette dependence are needed.

Risk Factors Associated With Driving After Cannabis Use Among Canadian Young Adults

This study identifid the most prominent risk factors associated with driving after cannabis use (DACU). 1,126 Canadian drivers (17–35 years old) who have used cannabis in the past 12 months completed an online questionnaire about sociodemographic information, substance use habits, cannabis effect expectancies, driving behaviours and peers’ behaviours and attitudes concerning DACU. A hierarchical logistic regression allowed identifying variables that were associated with DACU. Income (CA$30,000–CA$69,000), weekly-to-daily cannabis use, higher level of cannabis-related problems, expectation that cannabis facilitates social interactions, drunk driving, belief that DACU is safe, general risky driving behaviours, having a few friends who had DACU and injunctive norms predicted past 12-month DACU. Older age, holding negative expectations concerning cannabis, driving aggressively and perceived accessibility of public transportation decreased the probability of DACU. With restricted resources, programmes will be more efficient by targeting Canadian young adults most inclined to DACU by focussing on these risk factors.

Age at first alcohol use and weapon carrying among adolescents: Findings from the 2019 Youth Risk Behavior Survey

BACKGROUND

Although studies have investigated the association between alcohol use and violent behaviors such as weapon carrying, few studies have examined the association between age at first alcohol use and weapon-carrying among adolescents. The objective of this study was to investigate the association between age at first alcohol use and weapon carrying among adolescents.

METHODS

Data for this study came from the 2019 Youth Risk Behavior Survey. An analytic sample of 13,442 adolescents aged 14-18 years old (51% female) was analyzed using binary logistic regression. The outcome variable investigated in this study was weapon carrying during the past 30 days, and the main explanatory variable investigated was age at first alcohol use.

RESULTS

Of the 13,442 adolescents, 13.5% carried a weapon during the past 30 days, and 15.4% reported having their first alcoholic drink before age 13. In the multivariable logistic regression, adolescents who reported having alcohol before age 13 had more than double the odds of carrying a weapon when compared to those who never had alcohol before age 13 (AOR = 2.32, p < .001, 95% CI = 1.87-2.89). Other significant factors associated with weapon carrying include male gender, victim of bullying, teen dating violence, sexual violence, suicidal ideation, and history of substance use. Adolescents who self-identified as Black/African American or Hispanic were significantly less likely to carry a weapon when compared to adolescents who self-identified as non-Hispanic White.

CONCLUSION

The findings of this study underscore the importance of developing age appropriate intervention strategies to curb early initiation of alcohol use and weapon carrying among adolescents.

Roadside Drug Testing Approaches

The purpose of this review is to present an overview of roadside drug testing, driving enforcement, and drunk/drug driving detection around the world. Drunk and drug driving is a severe problem, not only in the UAE, but also around the world. This has important implications for road safety as drunk or drug driving may increase the chances of a driver’s involvement in a road crash when compared to a drug-free driver. Recently, due to increases in drug-impaired drivers’ crash involvement, many mobile roadside drug testing devices have been introduced to the market. These devices use oral fluid, urine or blood matrices. These are on-the-spot tests, which are easy to use and are applied by law enforcement agencies and the public. Law enforcement agencies most commonly use oral fluid to detect the presence of illicit drugs in drivers. This review discusses all the available devices in the market used by the authorities. It also describes the type of drugs widely abused by drivers along with behavioral testing methods. The different types of matrices used for roadside drug testing are also evaluated. Sample collection, storage, and pre-treatment methods are discussed, followed by the confirmatory analysis of positive samples. This article will significantly help law enforcement agencies compare and evaluate all the reliable roadside testing devices and new emerging confirmatory devices available to them in the market. This will help them make an informed decision on which device to adapt to their individual needs.

Post-legalization changes in marijuana use in a sample of young California adults

INTRODUCTION

Increasing marijuana use among young adults is a concern due to substantial acute and chronic health risks. More widespread use of marijuana may also lead to increased use of nicotine and tobacco products. California legalized commercial sales of marijuana for recreational use as of January 2018. To our knowledge no studies to date have examined subsequent changes in marijuana use. The goal of this study was to test the hypothesis that marijuana use frequency increased following legalization of recreational sales. We also hypothesized that increased marijuana frequency would predict greater frequency of nicotine/tobacco consumption.

METHODS

The study was a secondary analysis of a longitudinal study of tobacco use among non-daily cigarette smokers. Participants were 563 young adults (aged 18-24) enrolled in 2015-16 and followed quarterly for 3 years.

RESULTS

A piecewise multilevel regression model indicated that marijuana use frequency did not change over time, including following legalization. More frequent use was associated with younger age and identifying as white (ps < 0.001, which did not change after legalization. Marijuana frequency was moderated by sex (p < .001), with women reporting increasing and men decreasing use over time. It was also associated with tobacco use, and particularly with e-cigarette use following legalization (ps < 0.05).

CONCLUSIONS

Findings suggest legalization of recreational marijuana sales had a negligible overall impact on days of use among young adults, but may have prompted increased interest in marijuana among some, particularly women and e-cigarette users. The continuously evolving landscape around these products indicates that ongoing surveillance is critical.

A Digital Health Tool to Understand and Prevent Cannabis-Impaired Driving Among Youth: A Cross-sectional Study of Responses to a Brief Intervention for Cannabis Use

Background

Cannabis legalization has raised concern about an increased risk of cannabis-impaired driving, particularly among youth. Youth advocates and policy makers require cost-effective tools to target educational resources to promote responsible cannabis use.

Objective

The objective of this paper is threefold. First, it describes how a youth advocacy organization disseminated a low-cost digital brief intervention to educate and inform young people about responsible cannabis use. Second, it illustrates how digital tools can help promote understanding about attitudes and behaviors toward cannabis while simultaneously offering tailored education. Finally, this paper contributes to examining behavioral factors associated with youth cannabis-impaired driving by quantifying relationships between cannabis users' willingness to drive impaired and self-reported demographic and behavioral factors.

Methods

This paper analyzed data from 1110 completed Check Your Cannabis (CYC) brief interventions between March 2019 and October 2020. The CYC asks respondents a brief set of questions about their cannabis use and their personal beliefs and behaviors. Respondents receive comprehensive feedback about their cannabis use and how it compares with others. They also receive a summary of reported behaviors with brief advice. An ordered probit model was used to test relationships between cannabis use, demographics, and driving behaviors to gain further insights.

Results

The vast majority (817/1110, 73.6%) of respondents reported using cannabis. However, a much smaller share of respondents reported problems associated with their cannabis use (257/1110, 23.2%) or driving after cannabis use (342/1110, 30.8%). We found statistically significant relationships between driving after cannabis use and age; Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST) risk score; and polysubstance use. However, we did not find gender to be a significant determinant of driving after cannabis use. We estimated that every 10-point increase in the ASSIST score increased the probability of sometimes driving after cannabis use by 7.3% (P<.001). Relative to respondents who reported never drinking alcohol or using other substances with cannabis, those who sometimes drink or use other substances with cannabis were 13% (P<.001) more likely to sometimes or always drive after using cannabis.

Conclusions

The digital health tool cost the youth advocacy organization approximately Can $0.90 (US $0.71) per use. Due to the tool's unlimited use structure, the per-use cost would further decrease with increased use by the organization’s target population. Based on our results, public health campaigns and other interventions may consider tailoring resources to frequent cannabis users, youth with high ASSIST scores, and those with polysubstance abuse. The cost-effectiveness of delivering digital brief interventions with unlimited use is attractive, as increased use decreases the per-user cost. Further research examining the efficacy of digital health interventions targeting problematic cannabis use is required.

Cannabis-related driving and passenger behaviours among high school students: a cross-sectional study using survey data

BACKGROUND

Many youth report driving under the influence of cannabis (DUIC) and riding with a cannabis-impaired driver (RWCD), and many perceive that cannabis causes limited impairment. We examined associations of perceived risk of regular cannabis use with DUIC and RWCD, exploring differences by sex and rural setting.

METHODS

In a cross-sectional study, we examined DUIC and RWCD among high school students in grades 11 and 12 who participated in the 2016-2017 Canadian Student Tobacco, Alcohol and Drugs Survey. Private and public schools across 9 Canadian provinces were included. New Brunswick and the 3 territories were not included. Multinomial logistic regression models generated adjusted and unadjusted models for the associations.

RESULTS

A total of 52 103 students in grades 7-12, from 117 school boards and 699 schools, participated in the survey. The survey response rate was 76.2% (n = 52 103/68 415). In total, 14 520 students in grades 11 and 12 participated in the survey. Greater perceived risk of regular cannabis use was associated with reduced risk of DUIC and RWCD in a dose-response manner. Students perceiving that regular cannabis use posed great risk had an adjusted relative risk (RR) of 0.06 (95% confidence interval [CI] 0.04-0.10) of DUIC in the past 30 days compared with students perceiving that regular use posed no risk. Students perceiving that regular cannabis use posed great risk had an adjusted RR of 0.09 (95% CI 0.07-0.12) of RWCD in the past 30 days compared with students perceiving no such risk. Associations were consistent for male and female students and for those living in urban and rural areas.

INTERPRETATION

Students perceiving minimal risk from cannabis use reported greater engagement in cannabis-related risky driving behaviours. Given the importance of youth perceptions in shaping driving and passenger behaviours, efforts must be made to disseminate appropriate information regarding cannabis-related driving risks to high school students.

Informed Consent: A Policy Prescription for Communicating Benefit and Risk in State Medical Marijuana Programs

In creating medical marijuana laws, state governments signal to the public that marijuana can safely and effectively treat a wide range of diseases. In many cases, these state approvals overestimate the benefits of marijuana and understate the risks. After a comprehensive review of the medical literature, the National Academies of Sciences, Engineering, and Medicine identified six medical benefits from marijuana that were supported with at least a moderate level of medical evidence and 14 potential health hazards. In contrast, the average state medical marijuana program lists 18 medical benefits, and 24 state medical marijuana program websites say nothing about possible risks. Medication approval processes through the federal government traditionally require independent analysis of data from well-designed clinical trials that measure the effectiveness and capture the risks of adverse effects from specific doses of the medicine. These considerations are generally missing from state approvals of medical marijuana. The power to declare something to be a legitimate medicine comes with the responsibility to provide information that people need to use the medicine wisely. The authors recommend that states that declare marijuana to be a medicine should inform the public about the quality of medical evidence behind each approved use and publicize all scientifically credible risks.

International differences in patterns of cannabis use among adult cigarette smokers: Findings from the 2018 ITC Four Country Smoking and Vaping Survey

BACKGROUND

Although evidence shows that co-use of cigarettes and cannabis is common, there is little research examining if co-use patterns vary depending on the regulatory environment for cannabis. This study examined patterns of co-use and perceptions of relative harm among cigarette smokers in four countries with different histories, and at different stages of cannabis legalization.

METHODS

Data are from the 2018 International Tobacco Control 4CV Survey and included 10035 adult cigarette smokers from Canada, United States (US), Australia, and England. At the time of the survey, Canada and the US had relatively more permissive cannabis regulations compared to Australia and England.

RESULTS

Among this sample of 10035 cigarette smokers, Canada had the highest rate of cannabis co-use in the last 12 months (36.3%), followed by the US (29.1%), England (21.6%), and Australia (21.4%). Among past 12 month co-users (n = 3134), the US (40.2%) and Canada (35.2%) had the highest rates of daily cannabis use, followed by smokers in England (26.3%) and Australia (21.7%); Australian co-users had the highest rate of infrequent (

CONCLUSION

Patterns of tobacco and cannabis co-use differed between countries. Smokers in Canada and the US had higher rates of co-use, daily cannabis use, dual-daily use of both cannabis and cigarettes, and were more likely to perceive smoked cannabis as less harmful than cigarettes compared to England and Australia. Further attention as to how varying cannabis regulations may impact co-use patterns is warranted.

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Key Words

• Cannabis
• Co-use
• Harm Perceptions
• Policy
• Regulation
• Tobacco cigarettes

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MESH Headings Collapse

Grants

• P01 CA200512 NCI NIH HHS

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Affiliation(s)

Shannon Gravely Department of Psychology, University of Waterloo, Waterloo, Canada.
Pete Driezen Department of Psychology, University of Waterloo, Waterloo, Canada; School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada
Danielle M Smith Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
Ron Borland School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia; Cancer Council Victoria, Melbourne, VIC, Australia
Eric N Lindblom O'Neill Institute for National & Global Health Law, Georgetown University Law Center, Washington, DC United States
David Hammond School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada
Ann McNeill King's College London, Addictions Department, Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom; UK Centre for Tobacco & Alcohol Studies, Nottingham, United Kingdom
Andrew Hyland Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
K Michael Cummings Department of Psychiatry & Behavioral Sciences, Medical University of South Carolina, Charleston, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, United States
Gary Chan Centre for Youth Substance Abuse Research, The University of Queensland, Brisbane, QLD, Australia
Mary E Thompson Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada
Christian Boudreau Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada
Nadia Martin Department of Psychology, University of Waterloo, Waterloo, Canada
Janine Ouimet Department of Psychology, University of Waterloo, Waterloo, Canada
Ruth Loewen Department of Psychology, University of Waterloo, Waterloo, Canada
Anne C K Quah Department of Psychology, University of Waterloo, Waterloo, Canada
Maciej L Goniewicz Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
James F Thrasher Department of Health Promotion, Education & Behavior, Arnold School of Public Health, University of South Carolina, Columbia, United States; Tobacco Research Department, Center for Population Health Research, National Institute of Public Health, Cuernavaca, Mexico
Geoffrey T Fong Department of Psychology, University of Waterloo, Waterloo, Canada; School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada; Ontario Institute for Cancer Research, Toronto, Canada

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Modes of delivery in concurrent nicotine and cannabis use ("co-use") among youth: Findings from the International Tobacco Control (ITC) Survey

BACKGROUND

Cannabis use is more common among nicotine users than non-users. This study characterized concurrent use of nicotine and cannabis ("co-use") among 12,064 youth aged 16-19 years residing in Canada, the United States, and England in 2017. Methods: Data were from the ITC Youth Tobacco & Vaping Survey (Wave 1). Seven modes of cannabis delivery (MOD) were characterized by country of residence and past 30-day use of combusted tobacco and electronic cigarettes. Weighted multivariable regression models were fitted to assess the correlates of co-use and each cannabis MOD. Results: Seventy percent of cannabis users reported nicotine use. Co-users exhibited behavioral and demographic differences compared to exclusive users of either substance. "Smoking cannabis without tobacco" was the most popular form of use (78%). Use of nicotine-containing e-cigarettes was associated with "using an e-cigarette to vape cannabis oil/liquid" (aOR: 4.96, 95%CI: 2.23-11.06). Combustible tobacco use was associated with "smoking cannabis with tobacco in a joint/blunt" (aOR: 2.93, 95%CI: 1.89-4.56). Country-level differences were detected. Conclusions: Nicotine use is substantial among cannabis users, and associations exist between modes of delivery for both drugs. Results underscore the importance of studying cannabis and nicotine use concurrently, and the need to address the use of both substances in developing interventions for youth users.

Identification of biomarkers for the detection of subtle brain injury after cannabis and/or tramadol administration

Background

There is a need to identify biomarkers which could indicate the occurrence of brain injury in drug abuse.

Objectives

We aimed to investigate ubiquitin-C-terminal hydrolase-1 (UCH-L1), a neuronal cell body injury marker, the glial protein S-100 beta (S100β), and the glial fibrillary acidic protein (GFAP) as putative markers for neuronal injury due to cannabis, tramadol, or their combined use.

Materials and methods

Rats were treated with cannabis and/or tramadol subcutaneously daily for 6 weeks and UCH-L1, S100β, and GFAP were immunoassayed in the brain and serum.

Results

The results are as follows: (i) either cannabis or tramadol increased UCH-L1 and GFAP in the brain, (ii) serum UCH-L1 and GFAP increased by the highest dose of cannabis or tramadol, (iii) there was no additive effect for cannabis and tramadol on UCH-L1 or GFAP level in the brain or serum, (iv) S100β decreased in the brain by 5–20 mg/kg of cannabis and in the serum following 20 mg/kg of cannabis, and (v) S100β levels increased in the brain after 20 mg/kg of tramadol but decreased the brain and serum after both cannabis and tramadol. Cytoplasmic vacuolations, apoptotic cells, and gliosis were observed in the brain tissue of cannabis and/or tramadol-treated rats.

Conclusions

These results suggest that changes in UCH-L1, GFAP, or S100β are likely to reflect neurotoxicity and serum levels could be used to detect neuronal damage in chronic users.

The Prevalence of Vaping and Smoking as Modes of Delivery for Nicotine and Cannabis among Youth in Canada, England and the United States

Background: Vaping has become an increasingly common mode of administration for both nicotine and cannabis, with overlap among users, devices, as well as nicotine and cannabis companies. There is a need to understand patterns of use among youth, including the way nicotine and cannabis are administered. Methods: Data are from Wave 2 of the ITC Youth Tobacco and Vaping survey, an online survey conducted in 2018 among 16-19 year-olds recruited from commercial panels in Canada (n = 3757), England (n = 3819), and the U.S. (n = 3961). The prevalence of past 30-day vaping nicotine, non-nicotine and cannabis substances, as well as cannabis modes of use was examined. Logistic regression models examined between country differences in prevalence. Results: Past 30-day cannabis use was highest among Canadian youth (16.6%), followed by youth in the U.S. (13.8%) and England (9.0%). Vaping e-cigarettes was substantially more prevalent than vaping cannabis in all three countries. All forms of cannabis use were higher among Canadian and U.S. youth compared to England (p < 0.001 for all). Past 30-day cannabis users in the U.S. were more likely to report vaping cannabis oil (30.1%), and consuming solid concentrates such as wax and shatter (30.2%), compared to cannabis users in Canada (18.6% and 22.9%) and England (14.3% and 11.0%; p < 0.001 for all). Conclusions: Youth are administering cannabis and nicotine using a wide diversity of modes. Cannabis users in the U.S.-where an increasing number of states have legalized medical and non-medical cannabis-reported notably higher use of more potent cannabis products, including cannabis oils and extracts.