Cannabis Legalization and Detection of Tetrahydrocannabinol in Injured Drivers

Regulatory Framework for Cannabis: A Position Paper From the American College of Physicians

Cannabis, also known as marijuana, is the dried flowers, stems, seeds, and leaves of the Cannabis sativa plant. It contains more than 100 compounds, including tetrahydrocannabinol, which has psychoactive effects. Federal law prohibits the possession, distribution, and use of cannabis outside limited research activities, but most states have legalized cannabis for medical or recreational use. However, research into the potential therapeutic and adverse health effects of cannabis has been limited, in part because of the drug's federal legal status. In this position paper, the American College of Physicians (ACP) calls for the decriminalization of possession of small amounts of cannabis for personal use and outlines a public health approach to controlling cannabis in jurisdictions where it is legal. ACP recommends the rigorous evaluation of the health effects and potential therapeutic uses of cannabis and cannabinoids as well as research into the effects of legalization on cannabis use. It also calls for evidence-based medical education related to cannabis and increased resources for treatment of cannabis use disorder.

Road hazard: a systematic review of traffic injuries following recreational cannabis legalization

PURPOSE

Acute cannabis use is associated with impaired driving performance and increased risk of motor vehicle crashes. Following the Canadian Cannabis Act's implementation, it is essential to understand how recreational cannabis legalization impacts traffic injuries, with a particular emphasis on Canadian emergency departments. This study aims to assess the impact of recreational cannabis legalization on traffic-related emergency department visits and hospitalizations in the broader context of North America.

METHODS

A systematic review was conducted according to best practices and reported using PRISMA 2020 guidelines. The protocol was registered on July 5, 2022 (PROSPERO CRD42022342126). MEDLINE(R) ALL (OvidSP), Embase (OvidSP), CINAHL (EBSCOHost), and Scopus were searched without language or date restrictions up to October 12, 2023. Studies were included if they examined cannabis-related traffic-injury emergency department visits and hospitalizations before and after recreational cannabis legalization. The risk of bias was assessed. Meta-analysis was not possible due to heterogeneity.

RESULTS

Seven studies were eligible for the analysis. All studies were conducted between 2019 and 2023 in Canada and the United States. We found mixed results regarding the impact of recreational cannabis legalization on emergency department visits for traffic injuries. Four of the studies included reported increases in traffic injuries after legalization, while the remaining three studies found no significant change. There was a moderate overall risk of bias among the studies included.

CONCLUSIONS

This systematic review highlights the complexity of assessing the impact of recreational cannabis legalization on traffic injuries. Our findings show a varied impact on emergency department visits and hospitalizations across North America. This underlines the importance of Canadian emergency physicians staying informed about regional cannabis policies. Training on identifying and treating cannabis-related impairments should be incorporated into standard protocols to enhance response effectiveness and patient safety in light of evolving cannabis legislation.

Road safety implications of the partial legalisation of cannabis in Germany: protocol for a quasi-experimental study

INTRODUCTION

Germany is reforming its legal approach to cannabis, allowing the possession and cultivation of cannabis for recreational purposes. The objective of this study is to investigate the impact of the policy reform on (1) The prevalence of cannabis use in the general population and (2) Driving under the influence of cannabis (DUIC) among regular users.

METHODS AND ANALYSIS

A quasi-experimental research design will be employed, with repeated cross-sectional surveys on self-reported DUIC and cannabis use conducted at three measurement points in Germany (intervention group) and Austria (control group) over a 2-year observation period (2023-2025). Data will be collected from approximately 50 000 individuals aged between 18 years and 64 years. To minimise reporting biases in the measurement of DUIC, we will use direct and indirect assessments via crosswise model and motor vehicle accident data from official statistics. In a difference-in-difference framework, regression analyses and interrupted time series analysis will be carried out for hypothesis testing.

ETHICS AND DISSEMINATION

Participants will be informed about voluntary participation, data protection laws and the option to delete data on request. Ethical approval was obtained from the Local Psychological Ethics Committee of the Centre for Psychosocial Medicine in Hamburg, Germany (reference number: 0686). Findings will be disseminated through scientific networks and will be key for a comprehensive evaluation of the cannabis law reform. The findings will facilitate the design and implementation of road safety measures.

Off-road vehicle crashes: dangers of alcohol and drug impairment

BACKGROUND

Impaired driving is a public health issue, yet little is known concerning the prevalence of substance use in drivers involved in off-road vehicle crashes. The goal of the present study was to describe the demographics and prevalence of alcohol and drug use in drivers of off-road vehicle crashes.

METHODS

In this observational substudy, we collected clinical and toxicological data on all moderately or severely injured off-road vehicle drivers who had blood samples obtained within 6 h of the crash. Clinical data were extracted from patients' medical charts and toxicology analyses were performed for blood alcohol, cannabinoids, recreational drugs, and impairing medications.

RESULTS

Thirty-three injured drivers met the inclusion criteria. The mean age was 37.6 ± 13.4 years and 79% were male. Blood alcohol was detected in 58% of drivers and 42% of these were above the legal limit. Tetrahydrocannabinol was positive in 12% of drivers, and 18% were positive for recreational drugs. Opiates were detected in 21% of drivers. Overall, 85% were positive for at least one substance and 39% tested positive for multiple substances.

CONCLUSION

This study presents the first evidence of alcohol and drug use in off-road vehicle drivers after cannabis legalization in Canada. Our results show that over half of drivers in off-road vehicle crashes test positive for alcohol and 30% tested positive for THC, cocaine, or amphetamines. Opiates are also commonly detected in off-road vehicle drivers. Emergency department (ED) visits resulting from drug driving of off-road vehicles serve as an opportunity for screening, initiating treatment, and connecting patients to interventions for substance use disorders.

Neuromodulation for Cannabis Use: A Scoping Review

This scoping review explores the use of neuromodulation techniques in individuals with cannabis use. Our goal was to determine whether cannabis use alters cortical excitation and inhibition in the context of neuromodulation and to determine whether neuromodulation affects craving and cannabis use patterns. A systematic search was conducted using PubMed, OVID Medline, and PsycINFO from inception to 20 December 2022. Our review identified ten relevant studies, eight of which used Transcranial Magnetic Stimulation (TMS), while two employed Transcranial Direct Current Stimulation (tDCS). Findings from TMS studies suggest that cannabis users exhibit altered cortical inhibition, with decreased short interval intracortical inhibition (SICI) compared to non-users. Single sessions of rTMS did not have any impact on cannabis craving. By contrast, two studies found that multiple sessions of rTMS reduced cannabis use, but these changes did not meet the threshold for statistical significance and both studies were limited by small sample sizes. The two included tDCS studies found contradictory results, with one showing reduced cannabis craving with active treatment and another showing no effect of active treatment on craving compared to sham. Future studies should further explore the effects of multiple treatment sessions and different neuromodulation modalities.

Cannabis legalization and driving under the influence of cannabis and driving under the influence of alcohol among adult and adolescent drivers in Ontario, Canada (2001-2019)

BACKGROUND

The impacts of cannabis legalization on driving under the influence of cannabis and driving under the influence of alcohol among adults and adolescents were examined in Ontario, Canada.

METHODS

Data were sourced from adult (N=38,479) and adolescent (N=23,216) populations-based surveys (2001-2019). The associations between cannabis legalization and driving within an hour of using cannabis and driving within an hour of drinking two or more drinks of alcohol were quantified using logistic regression, with testing of multiplicative interactions between cannabis legalization and age and sex. All analyses were conducted separately for adults and adolescents and restricted to participants with a valid driver's license.

RESULTS

Cannabis legalization was not associated with driving within an hour of using cannabis among adults (OR, 95% CI: 1.21, 0.69-2.11). However, a multiplicative interaction indicated that there was an increased likelihood of driving within an hour of using cannabis among adults ≥55 years of age (4.23, 1.85-9.71) pre-post cannabis legalization. Cannabis legalization was not associated with driving within an hour of using cannabis among adolescents (0.92, 0.72-1.16), or with driving within an hour of consuming two or more drinks of alcohol among adults (0.78, 0.51-1.20) or adolescents (0.87, 0.42-1.82).

CONCLUSIONS

An increased likelihood of driving under the influence of cannabis among adults ≥55 years of age was detected in the year following cannabis legalization, suggesting the need for greater public awareness and education and police monitoring and enforcement concerning driving under the influence of cannabis, particularly among older adults.

Perceptions and Attitudes Related to Driving after Cannabis Use in Canadian and US Adults

BACKGROUND

This study examined the risk perceptions related to driving after cannabis use (DACU) among Canadian and US adults who used cannabis in the past six months.

METHODS

Perceptions of danger, normative beliefs, perceived likelihood of negative consequences, and other driving-related variables were collected via online surveys in Canadian (n = 158; 50.0% female, 84.8% White, mean age = 32.73 years [SD = 10.61]) and US participants (n = 678; 50.9% female, 73.6% White, mean age = 33.85 years [SD = 10.12]). Driving cognitions and DACU quantity/frequency were compared between samples using univariate analyses of variance, and Spearman's (ρ) correlations were performed to examine associations between driving cognitions and DACU quantity/frequency.

RESULTS

The two samples did not significantly differ in self-reported level of cannabis use, lifetime quantity of DACU, or the number of times they drove within two hours of cannabis use in the past three months (Ps > .12). Compared to US participants, Canadians perceived driving within two hours of cannabis use as more dangerous (P < 0.001, ηp2 = 0.013) and reported more of their friends would disapprove of DACU (P = 0.03, ηp2 = 0.006). There were no differences in the number of friends who would refuse to ride with a driver who had used cannabis (P = 0.15) or the perceived likelihood of negative consequences (Ps > 0.07). More favorable perceptions were significantly correlated with greater lifetime DACU and driving within two hours of use (ρ = 0.25-0.53, Ps < 0.01).

CONCLUSIONS

These findings reveal differences in distal risk factors for DACU between Canada and the US and may inform prevention efforts focusing on perceptions of risk and social acceptance of DACU.

The implementation and public health impacts of cannabis legalization in Canada: a systematic review

AIMS

We provide a narrative summary of research on changes in cannabis arrests, cannabis products and prices, cannabis use and cannabis-related harm since legalization.

METHODS

We systematically searched for research on the impacts of cannabis legalization in Canada in PubMed, Embase, Statistics Canada and government websites and Google Scholar, published between 2006 and 2021.

RESULTS

Cannabis legalization in Canada has been followed by substantial reductions in cannabis-related arrests and cannabis prices. It has also increased adults' access to a diverse range of cannabis products, including edibles and extracts. The prevalence of cannabis use among young adults has increased, but there have been no marked increases or decreases in use among high school students or changes in the prevalence of daily or near-daily use. Legalization has been associated with increased adult hospital attendances for psychiatric distress and vomiting, unintentional ingestion of edible cannabis products by children and hospitalizations for cannabis use disorders in adults. There is conflicting evidence on whether cannabis-impaired driving has increased since legalization. There is suggestive evidence that presentations to emergency departments with psychoses and cannabis use disorders may have increased since legalization.

CONCLUSIONS

Legalization of cannabis in Canada appears to have reduced cannabis arrests and increased access to a variety of more potent cannabis products at lower prices. Since 2019, recent cannabis use in Canada has modestly increased among adults but not among adolescents. There is evidence of increased acute adverse effects of cannabis among adults and children.

Trends in drivers testing positive for drugs of abuse in oral fluid from 2018 to 2021 in France

BACKGROUND

Driving under the influence of drugs (DUID) is a risk factor for traffic accidents. The testing of oral fluid by roadside immunochromatography and laboratory-confirmed chromatography coupled to mass spectrometry (LC-MS/MS) analysis to detect drug abuse has increased in France. The aim of this study was to describe the trends observed in drivers testing positive for illicit drugs in oral fluid and to investigate the concordance between the two analytical methods used.

METHODS

We received for confirmation 3051 oral fluid samples from drivers who had tested positive at the roadside with a Drugwipe-5S® device between 2018 and 2021 around Grenoble, France. Samples were collected with FLOQSwab® and analyzed by LC-MS/MS (THC, amphetamine, methamphetamine, MDMA and MDA, MDEA, cocaine and benzoylecgonine, morphine and 6-monoacetylmorphine) at Grenoble Alpes University Hospital, France. Binomial logistic regression was performed to evaluate consumption trends.

RESULTS

Most of the drivers were men (93.2%), with a median age of 26 years (range: 14-66 years). Cannabis (94.6%) cocaine (17.5%) and MDMA (2.5%) were the drugs most frequently detected. Poly-drug use was observed in 17.3% of drivers and involved cannabis and cocaine in 85.3% of these drivers. Poly-drug use was more frequent among drivers over the age of 32 years (OR, 3.48; 95% CI, 2.59-4.68; p ≤ .001), as was cocaine use (OR, 5.15; 95% CI, 3.75-7.08; p ≤ .001). The frequency of positive tests for amphetamines was higher in women than in men (OR, 2.53; 95% CI, 1.50-4.27; p ≤ .001). The positive predictive value of Drugwipe-5S was 98.2% for cannabis, 22.6% for amphetamines, 75.4% for cocaine and 17.3% for opiates. At least one discrepancy between Drugwipe-5S® and LC-MS/MS results was observed for 22.3% of the samples tested.

CONCLUSION

We report recent trends for drivers testing positive for illicit drugs in oral fluid in France. Cannabis was the most prevalent drug of abuse identified, suggesting that a general prevention program might be useful. Our results also highlight the need for LC-MS/MS confirmation when screening oral fluid for drugs of abuse.

Implications of Cannabis Legalization on Substance-Related Benefits and Harms for People Who Use Opioids: A Canadian Perspective

In 2018, Canada enacted the Cannabis Act, becoming only the second country (after Uruguay) to legalize the recreational consumption of cannabis. Although there is ongoing global disagreement on the risk-benefit profile of cannabis with increasing legalization in many parts of the world, the evidence of rising cannabis use prevalence postlegalization has been consistent. In contrast, postlegalization changes in various cannabis-related metrics have been inconsistent in Canada and other parts of the world. Furthermore, the implications of cannabis legalization on substance-related harms and benefits for people who use unregulated drugs, particularly opioids, remain unclear. Finally, although Canada did not legalize cannabis to address the opioid crisis, there is rising scientific and popular interest in the therapeutic potential of cannabis to mitigate opioid-related harms. This perspective highlights the implications of cannabis legalization on substance-related benefits and harms for people who use opioids, the current state of Canadian research, and suggestions for future directions.

Cannabis-Involved Traffic Injury Emergency Department Visits After Cannabis Legalization and Commercialization

Importance

The impact of nonmedical cannabis legalization on traffic injuries and cannabis involvement in traffic injuries is unclear.

Objective

To examine changes in the number and characteristics of cannabis-involved traffic injury emergency department (ED) visits from before to after legalization and subsequent commercialization (ie, increased retail store and product availability) of cannabis in Ontario, Canada.

Design, Setting, and Participants

This repeated cross-sectional study examined changes in cannabis- and alcohol-involved traffic injury ED visits in Ontario, Canada, during 3 time periods: prelegalization (January 2010-September 2018), legalization with product and retail store restrictions (October 2018-February 2020), and commercialization with new products and expanded number of stores, which coincided with the COVID-19 pandemic (March 2020-December 2021). All individuals aged 16 years and older eligible for Ontario's Universal Health Coverage were included. Season- and time-adjusted quasi-Poisson models were used to generate rate ratios with 95% CIs. Data were analyzed from March to April 2023.

Main Outcomes and Measures

Quarterly counts of cannabis-involved ED visits for traffic injury.

Results

There were 947 604 traffic injury ED visits, of which 426 (0.04%) had documented cannabis involvement and 7564 (0.8%) had documented alcohol involvement. Of the 418 individuals with documented cannabis involvement, 330 (78.9%) were male, 109 (25.6%) were aged 16 to 21 years (mean [SD] age at visit, 30.6 [12.0] years), and 113 (27.0%) had an ED visit or hospitalization for substance use in the 2 years before their traffic injury ED visit. Annual rates of cannabis-involved traffic injury ED visits increased 475.3% over the study period (0.18 visits per 1000 total motor vehicle collisions in 2010 to 1.01 in 2021). Over the same period, alcohol-involved traffic injury ED visits increased by 9.4% (8.03 in 2010 to 8.79 per 1000 traffic injury ED visits in 2021). Legalization with restrictions was associated with a 94% increase in the quarterly rate of cannabis involvement in traffic injury ED visits relative to prelegalization (adjusted rate ratio [aRR], 1.94; 95% CI, 1.37-2.75). Commercialization/COVID-19 was associated with a greater increase of 223% in rates (aRR, 3.23; 95% CI, 2.42-4.33). After adjusting for time trends before legalization, only commercialization/COVID-19 was associated with increased rates. Male sex (adjusted odds ratio [aOR], 3.38; 95% CI, 2.66-4.29), living in the lowest-income neighborhood (aOR, 1.92; 95% CI, 1.39-2.67), being aged 19 to 21 years (aOR, 4.67; 95% CI, 3.27-6.67), and having a prior cannabis-related ED visit (aOR, 8.03; 95% CI, 5.85-11.02) were all positively associated with cannabis involvement during a traffic injury ED visit.

Conclusions and Relevance

This cross-sectional study found large increases in cannabis involvement in ED visits for traffic injury over time, which may have accelerated following nonmedical cannabis commercialization. Although the frequency of visits was rare, they may reflect broader changes in cannabis-impaired driving. Greater prevention efforts, including targeted education and policy measures, in regions with legal cannabis are indicated.

The development of a Cannabis Knowledge Assessment Tool (CKAT)

BACKGROUND

Misconceptions about the health risks of cannabis remain prevalent, indicating the need to improve public health messaging and determine the effectiveness of educational programming. Our objective was to develop a standardized questionnaire to measure knowledge about cannabis in the context of cannabis legalization.

METHODS

A Cannabis Knowledge Assessment Tool (CKAT) was created using the Delphi method. A purposive sample of healthcare professionals, policymakers, academics, patients, and students served as the content and development experts. Principal component analysis from the codes identified from open-ended feedback guided the item development. Upon completion, the CKAT was administered as a pre- and post-test in four schools (7th and 9th Grade) in Canada. The data were analysed to determine whether knowledge scores changed after participating in a cannabis education program.

RESULTS

Twenty-four experts initially participated in the Delphi process and 18 (75% retention) continued throughout. Principal component analysis identified 3 domains: 1) effects of cannabis on the individual, 2) general information about cannabis, and 3) cannabis harm reduction. The final questionnaire consisted of 16 multiple-true-false questions (64 items) and received a Flesch-Kincaid Grade Level of 6.3, and a SMOG index score of 7.6. The CKAT was completed by 132 students; seventy-three 7th grade and fifty-nine 9th grade students. The baseline mean CKAT score was 46.2 (SD:5.5), which increased to 50.7 (SD:4.6) after the cannabis educational program (p<0.05).

CONCLUSIONS

A novel tool to measure knowledge of cannabis was developed and piloted in 7th grade and 9th grade students. Future studies are required to test usability and validity of the CKAT in other contexts.

Demographic and clinical profile of an inception cohort of road trauma survivors

BACKGROUND

Road trauma is a major public health concern, often resulting in reduced health-related quality of life and prolonged absenteeism from work even after so-called 'minor' injuries that do not result in hospitalization. This manuscript compares pre-injury health, sociodemographic characteristics and injury details between age, sex, and road user categories in a cohort of 1,480 road trauma survivors.

METHODS

This was a prospective observational inception cohort study of road trauma survivors recruited between July 2018 and March 2020 from three trauma centres in British Columbia, Canada. Participants were aged ≥ 16 years and arrived in a participating emergency department within 24 h of involvement in a motor vehicle collision. Data were collected from structured interviews and review of medical records.

RESULTS

The cohort of 1,480 road trauma survivors included 280 pedestrians, 174 cyclists, 118 motorcyclists, 683 motor vehicle drivers, and 225 passengers. Median age was 40 (IQR = [27, 57]) years; 680 (46%) were female. Males and younger patients were significantly more likely to report better pre-injury physical health. Motorcyclists and cyclists tended to report better physical health and less severe somatic symptoms, whereas pedestrians and motor vehicle drivers reported better mental health. Injury severity and hospital admission rates were higher in pedestrians and motorcyclists and lower in motorists. Upper and lower extremity injuries were most common in pedestrians, cyclists and motorcyclists, whereas neck injuries were most common in motor vehicle drivers and passengers.

CONCLUSIONS

In a large cohort of road trauma survivors, overall injury severity was low. Motorcyclists and pedestrians, but not cyclists, had more severe injuries than motorists. Extremity injuries were more common in vulnerable road users. Future research will investigate one-year recovery outcomes and identify risk factors for poor recovery.

High-'n'-dry? A comparison of cannabis and alcohol use in drivers presenting to hospital after a vehicular collision

DESIGN

This was a prospective observational study.

BACKGROUND AND AIMS

The characteristics of cannabis-involved motor vehicle collisions are poorly understood. This study of injured drivers identifies demographic and collision characteristics associated with high tetrahydrocannabinol (THC) concentrations.

SETTING

The study was conducted in 15 Canadian trauma centres between January 2018 and December 2021.

CASES

The cases (n = 6956) comprised injured drivers who required blood testing as part of routine trauma care.

MEASUREMENTS

We quantified whole blood THC and blood alcohol concentration (BAC) and recorded driver sex, age and postal code, time of crash, crash type and injury severity. We defined three driver groups: high THC (THC ≥ 5 ng/ml and BAC = 0), high alcohol (BAC ≥ 0.08% and THC = 0) and THC/BAC-negative (THC = 0 = BAC). We used logistic regression techniques to identify factors associated with group membership.

FINDINGS

Most injured drivers (70.2%) were THC/BAC-negative; 1274 (18.3%) had THC > 0, including 186 (2.7%) in the high THC group; 1161 (16.7%) had BAC > 0, including 606 (8.7%) in the high BAC group. Males and drivers aged less than 45 years had higher adjusted odds of being in the high THC group (versus the THC/BAC-negative group). Importantly, 4.6% of drivers aged less than 19 years had THC ≥ 5 ng/ml, and drivers aged less than 19 years had higher unadjusted odds of being in the high THC group than drivers aged 45-54 years. Males, drivers aged 19-44 years, rural drivers, seriously injured drivers and drivers injured in single-vehicle, night-time or weekend collisions had higher adjusted odds ratios (aORs) for being in the high alcohol group (versus THC/BAC-negative). Drivers aged less than 35 or more than 65 years and drivers involved in multi-vehicle, daytime or weekday collisions had higher adjusted odds for being in the high THC group (versus the high BAC group).

CONCLUSIONS

In Canada, risk factors for cannabis-related motor vehicle collisions appear to differ from those for alcohol-related motor vehicle collisions. The collision factors associated with alcohol (single-vehicle, night-time, weekend, rural, serious injury) are not associated with cannabis-related collisions. Demographic factors (young drivers, male drivers) are associated with both alcohol and cannabis-related collisions, but are more strongly associated with cannabis-related collisions.

Severe outcomes following pediatric cannabis intoxication: a prospective cohort study of an international toxicology surveillance registry

INTRODUCTION

An increasing number of jurisdictions have legalized recreational cannabis for adult use. The subsequent availability and marketing of recreational cannabis has led to a parallel increase in rates and severity of pediatric cannabis intoxications. We explored predictors of severe outcomes in pediatric patients who presented to the emergency department with cannabis intoxication.

METHODS

In this prospective cohort study, we collected data on all pediatric patients (<18 years) who presented with cannabis intoxication from August 2017 through June 2020 to participating sites in the Toxicology Investigators Consortium. In cases that involved polysubstance exposure, patients were included if cannabis was a significant contributing agent. The primary outcome was a composite severe outcome endpoint, defined as an intensive care unit admission or in-hospital death. Covariates included relevant sociodemographic and exposure characteristics.

RESULTS

One hundred and thirty-eight pediatric patients (54% males, median age 14.0 years, interquartile range 3.7-16.0) presented to a participating emergency department with cannabis intoxication. Fifty-two patients (38%) were admitted to an intensive care unit, including one patient who died. In the multivariable logistic regression analysis, polysubstance ingestion (adjusted odds ratio = 16.3; 95% confidence interval: 4.6-58.3; P < 0.001)) and cannabis edibles ingestion (adjusted odds ratio = 5.5; 95% confidence interval: 1.9-15.9; P = 0.001) were strong independent predictors of severe outcome. In an age-stratified regression analysis, in children older than >10 years, only polysubstance abuse remained an independent predictor for the severe outcome (adjusted odds ratio 37.1; 95% confidence interval: 6.2-221.2; P < 0.001). As all children 10 years and younger ingested edibles, a dedicated multivariable analysis could not be performed (unadjusted odds ratio 3.3; 95% confidence interval: 1.6-6.7).

CONCLUSIONS

Severe outcomes occurred for different reasons and were largely associated with the patient's age. Young children, all of whom were exposed to edibles, were at higher risk of severe outcomes. Teenagers with severe outcomes were frequently involved in polysubstance exposure, while psychosocial factors may have played a role.

Pilot trial of a telehealth-delivered behavioral economic intervention promoting cannabis-free activities among adults with cannabis use disorder

BACKGROUND

Cannabis is increasingly consumed and increasingly perceived as harmless. Among those whose use develops into a cannabis use disorder (CUD), <5% initiate and engage in treatment. Thus, novel options for low-barrier, appealing treatments are needed to foster engagement in care.

METHODS

We conducted an open trial of a telehealth-delivered multicomponent behavioral economic intervention for non-treatment-engaged adults with CUD. Participants with CUD were recruited from a health system and screened for eligibility. Participants completed behavioral economic indices (cannabis demand, proportionate cannabis-free reinforcement), measures of cannabis use and mental health symptoms, and provided open-ended feedback on the intervention experience.

RESULTS

Of the 20 participants who enrolled and engaged in the initial intervention session, 70% (14 out of 20) completed all intervention components. All participants were satisfied/very satisfied with the intervention and 85.7% reported the telehealth delivery made it at least slightly easier/more likely for them to receive substance use care. Baseline to immediate post-treatment, behavioral economic cannabis demand decreased (intensity: Hedges' g = 0.14, maximum total expenditure: Hedges' g = 0.53, maximum expenditure for a single hit: Hedges' g = 0.10) and proportionate cannabis-free reinforcement (Hedges' g = 0.12) increased. Past-month total cannabis use decreased by 8.9% from baseline to post-treatment (Hedges' g = 0.39), along with decreases in recent depression (Hedges' g = 0.50) and anxiety symptoms (Hedges' g = 0.29).

DISCUSSION

These preliminary findings suggest that this behavioral economic intervention was highly acceptable and feasible for adults with untreated CUD. Changes in potential mechanisms of behavior change (cannabis demand, proportionate cannabis-free reinforcement) were consistent with reduced frequency of cannabis use and improved mental health outcomes.

The Impact of Recreational Cannabis Legalization on Cannabis Use and Associated Outcomes: A Systematic Review

Background

Recreational cannabis legalization has become more prevalent over the past decade, increasing the need to understand its impact on downstream health-related outcomes. Although prior reviews have broadly summarized research on cannabis liberalization policies (including decriminalization and medical legalization), directed efforts are needed to synthesize the more recent research that focuses on recreational cannabis legalization specifically. Thus, the current review summarizes existing studies using longitudinal designs to evaluate impacts of recreational cannabis legalization on cannabis use and related outcomes.

Method

A comprehensive bibliographic search strategy revealed 61 studies published from 2016 to 2022 that met criteria for inclusion. The studies were predominantly from the United States (66.2%) and primarily utilized self-report data (for cannabis use and attitudes) or administrative data (for health-related, driving, and crime outcomes).

Results

Five main categories of outcomes were identified through the review: cannabis and other substance use, attitudes toward cannabis, health-care utilization, driving-related outcomes, and crime-related outcomes. The extant literature revealed mixed findings, including some evidence of negative consequences of legalization (such as increased young adult use, cannabis-related healthcare visits, and impaired driving) and some evidence for minimal impacts (such as little change in adolescent cannabis use rates, substance use rates, and mixed evidence for changes in cannabis-related attitudes).

Conclusions

Overall, the existing literature reveals a number of negative consequences of legalization, although the findings are mixed and generally do not suggest large magnitude short-term impacts. The review highlights the need for more systematic investigation, particularly across a greater diversity of geographic regions.

Did the cannabis recreational use law affect traffic crash outcomes in Toronto? Building evidence for the adequate number of authorised cannabis stores' thresholds

INTRODUCTION

In the past decade, a group of studies has begun to explore the association between cannabis recreational use policies and traffic crashes. After these policies are set in place, several factors may affect cannabis consumption, including the number of cannabis stores (NCS) per capita. This study examines the association between the enactment of Canada's Cannabis Act (CCA) (18 October 2018) and the NCS (allowed to function from 1 April 2019) with traffic injuries in Toronto.

METHODS

We explored the association of the CCA and the NCS with traffic crashes. We applied two methods: hybrid difference-in-difference (DID) and hybrid-fuzzy DID. We used generalised linear models using CCA and the NCS per capita as the main variables of interest. We adjusted for precipitation, temperature and snow. Information is gathered from Toronto Police Service, Alcohol and Gaming Commission of Ontario, and Environment Canada. The period of analysis was from 1 January 2016 to 31 December 2019.

RESULTS

Regardless of the outcome, neither the CCA nor the NCS is associated with concomitant changes in the outcomes. In hybrid DID models, the CCA is associated with non-significant decreases of 9% (incidence rate ratio 0.91, 95% confidence interval 0.74,1.11) in traffic crashes and in the hybrid-fuzzy DID models, the NCS are associated with nonsignificant decreases of 3% (95% confidence interval - 9%, 4%) in the same outcome.

DISCUSSION AND CONCLUSIONS

This study observes that more research is needed to better understand the short-term effects (April to December 2019) of NCS in Toronto on road safety outcomes.

Cannabis positivity rates in 17 emergency departments across the United States with varying degrees of marijuana legalization

BACKGROUND

Many states in the United States have progressed towards legalization of marijuana including decriminalization, medicinal and/or recreational use. We studied the impact of legalization on cannabis-related emergency department visits in states with varying degrees of legalization.

METHODS

Seventeen healthcare institutions in fifteen states (California, Colorado, Connecticut, Florida, Iowa, Kentucky, Maryland, Massachusetts, Missouri, New Hampshire, Oregon, South Carolina, Tennessee, Texas, Washington) participated. Cannabinoid immunoassay results and cannabis-related International Classification of Diseases (ninth and tenth versions) codes were obtained for emergency department visits over a 3- to 8-year period during various stages of legalization: no state laws, decriminalized, medical approval before dispensaries, medical dispensaries available, recreational approval before dispensaries and recreational dispensaries available. Trends and monthly rates of cannabinoid immunoassay and cannabis-related International Classification of Diseases code positivity were determined during these legalization periods.

RESULTS

For most states, there was a significant increase in both cannabinoid immunoassay and International Classification of Diseases code positivity as legalization progressed; however, positivity rates differed. The availability of dispensaries may impact positivity in states with medical and/or recreational approval. In most states with no laws, there was a significant but smaller increase in cannabinoid immunoassay positivity rates.

CONCLUSIONS

States may experience an increase in cannabis-related emergency department visits with progression toward marijuana legalization. The differences between states, including those in which no impact was seen, are likely multifactorial and include cultural norms, attitudes of local law enforcement, differing patient populations, legalization in surrounding states, availability of dispensaries, various ordering protocols in the emergency department, and the prevalence of non-regulated cannabis products.

Impacts of recreational cannabis legalization on use and harms: A narrative review of sex/gender differences

Legalization of cannabis use for non-medical (recreational) purposes is changing the global cannabis landscape. As attitudes toward cannabis use become more positive and prevalence of use increases in complex ways, concerns emerge about the potential for increased cannabis-attributable harms. Understanding the who, why, and when of this likely increase in cannabis-attributable harms is thus an important public health priority. Both sex and gender contribute to variability in the use, effects, and harms of cannabis and thus sex/gender considerations are important when evaluating the impacts of cannabis legalization. The goal of this narrative review is to broadly discuss sex/gender differences in attitudes toward and prevalence of cannabis use, whether there are sex/gender differences in the impacts of cannabis legalization, and why these sex/gender differences might exist. One of our strongest conclusions is that men have always been more likely to use cannabis than women, yet the sex/gender gap in prevalence of cannabis use has narrowed over time, and this might be partly due to cannabis legalization. The existing evidence suggests that there have also been sex/gender differences in the impacts of legalization on cannabis-attributable harms such as cannabis-involved motor vehicle collisions and hospitalizations, though these results are more variable. The body of literature reviewed has focused almost exclusively on samples of cisgender research participants, and thus future research should encourage inclusion of transgender and gender-diverse participants. More consideration of sex- and gender-based analysis in research evaluating long-term impacts of cannabis legalization is a clear research priority.

Prevalence and association of non-medical cannabis use with post-procedural healthcare utilisation in patients undergoing surgery or interventional procedures: a retrospective cohort study

BACKGROUND

There is paucity of data regarding prevalence and key harms of non-medical cannabis use in surgical patients. We investigated whether cannabis use in patients undergoing surgery or interventional procedures patients was associated with a higher degree of post-procedural healthcare utilisation.

METHODS

210,639 adults undergoing non-cardiac surgery between January 2008 and June 2020 at an academic healthcare network in Massachusetts, USA, were included. The primary exposure was use of cannabis, differentiated by reported ongoing non-medical use, self-identified during structured, preoperative nursing/physician interviews, or diagnosis of cannabis use disorder based on International Classification of Diseases, 9th/10th Revision, diagnostic codes. The main outcome measure was the requirement of advanced post-procedural healthcare utilisation (unplanned intensive care unit admission, hospital re-admission or non-home discharge).

FINDINGS

16,211 patients (7.7%) were identified as cannabis users. The prevalence of cannabis use increased from 4.9% in 2008 to 14.3% by 2020 (p < 0.001). Patients who consumed cannabis had higher rates of psychiatric comorbidities (25.3 versus 16.8%; p < 0.001) and concomitant non-tobacco substance abuse (30.2 versus 7.0%; p < 0.001). Compared to non-users, patients with a diagnosis of cannabis use disorder had higher odds of requiring advanced post-procedural healthcare utilisation after adjusting for patient characteristics, concomitant substance use and socioeconomic factors (aOR [adjusted odds ratio] 1.16; 95% CI 1.02-1.32). By contrast, patients with ongoing non-medical cannabis use had lower odds of advanced post-procedural healthcare utilisation (aOR 0.87; 95% CI 0.81-0.92, compared to non-users).

INTERPRETATION

One in seven patients undergoing surgery or interventional procedures in 2020 reported cannabis consumption. Differential effects on post-procedural healthcare utilisation were observed between patients with non-medical cannabis use and cannabis use disorder.

FUNDING

This work was supported by an unrestricted philantropic grant from Jeff and Judy Buzen to Maximilian S. Schaefer.

Cannabis-Legalisierung in Deutschland

Zusammenfassung: Zielsetzung: Die deutsche Bundesregierung hat beschlossen, den nicht-medizinischen Cannabis-Gebrauch und -Vertrieb zu legalisieren, und Kernpunkte des vorgesehenen Regelwerks vorgelegt. Einige dieser Kernpunkte werden aus der Sicht internationaler Erfahrungen und wissenschaftlicher Evidenz zur Legalisierung – insbesondere mit Blick auf Massnahmen und Ziele öffentlicher Gesundheit – eingeschätzt und kommentiert. Methodik: Selektive Zusammenfassung und policy-analytische Anwendung wissenschaftlicher Evidenz. Ergebnisse: Ein erheblicher Anteil von Cannabis-bezogenen Gesundheitsproblemen hängt mit dem Konsum von Hochpotenz- (THC) Produkten zusammen; allerdings würden kategorische THC-Grenzwerte für legal verfügbares Cannabis diese im Gesamten wahrscheinlich nicht reduzieren sondern primär Hochrisiko-Konsumenten weiter in der Illegalität belassen. Die Mindestalter-Grenze von 18 Jahren für legales Cannabis macht primär politischen Sinn und repräsentiert nicht unbedingt optimalen Gesundheits- oder sozialen Schutz für junge Konsumenten; allerdings wird der Cannabis-Konsum bei Minderjährigen wahrscheinlich weiter hoch blieben. Eine substanz-übergreifende, gesundheits-orientierte Angleichung mit den Gesetzesregelungen für andere Substanzen (z. B. Alkohol) wäre sinnvoll. Das Fahren unter Cannabis-Einfluss ist relativ häufig, und kann zu Verletzungs- und Todesfällen, und damit erheblicher Gesundheitsbelastung führen; seine Kontrolle braucht gezielte Aufklärungs- und Abschreckungs-Maßnahmen. Cannabis-Legalisierung ist mit einschlägigen internationalen (z. B. UN) Konventionen generell schwierig zu vereinbaren, sollte aber dazu genutzt werden, diese grundsätzlich auf der Basis von Prinzipien des Gesundheitsschutzes zu erneuern. Schlussfolgerungen: Für die Cannabis-Legalisierung in Deutschland gibt es kein perfektes Regelwerk; einige Kern-Ziele werden nur über Kompromiss-Ansätze zu erreichen sein, die im Zweifelsfall angepasst werden müssen. Wenn implementiert, wird Deutschland wichtige Daten zur Cannabis-Legalisierung als Politik-Option bieten können, wozu ein systematisches und umfassendes Prozess- und Ergebnis-Monitoring durchgeführt werden muss.

Changes in health harms due to cannabis following legalisation of non-medical cannabis in Canada in context of cannabis commercialisation: A scoping review

ISSUE

On 17 October 2018, Canada legalised non-medical cannabis. Critically, the cannabis market in Canada has changed considerably since legalisation. In this scoping review, we identified available evidence on changes in cannabis-related health harms following legalisation and contextualised findings based on legal market indicators.

APPROACH

Electronic searches were conducted to identify studies that compared changes in cannabis-related health harms pre- and post-legalisation. We contextualised each study by the mean per capita legal cannabis stores and sales during the study period and compared study means to per capita stores and sales on October 2021-3 years following legalisation.

IMPLICATIONS AND CONCLUSIONS

Some measures of cannabis harms have increased since legalisation but studies to date have captured periods of relatively low market maturity. Longer-term monitoring of health harms as the market continues to expand is indicated.

Developments and Changes in Primary Public Health Outcome Indicators Associated with the Legalization of Non-Medical Cannabis Use and Supply in Canada (2018): A Comprehensive Overview

Canada legalized non-medical cannabis use and supply for adults in 2018. We examined developments and changes associated with the legalization policy reform on key indicators for public health, namely cannabis (including frequent/problematic) use prevalence, cannabis-related hospitalizations, cannabis-impaired driving, and cannabis sourcing. We identified peer-reviewed and "grey" study data that featured population-level or other quasi-representative samples and comparable outcome data for pre- and post-legalization periods, including possible trends of changes over time. Cannabis use has increased in select population groups, with use modes shifting away from smoking. Evidence on cannabis-related hospitalizations (e.g., for mental health) is mixed. The prevalence of cannabis-impaired driving appears to be generally steady but THC exposure among crash-involved drivers may have increased. Increasing proportions of users obtain cannabis products from legal sources but some-especially regular-users continue to use illicit sources. Overall, data suggest a mixed and inconclusive picture on cannabis legalization's impacts on essential public health indicators, including select extensions in trends from pre-legalization.

The impact of cannabis legalization for recreational purposes on youth: A narrative review of the Canadian experience

Cannabis legalization for non-medical purposes (subsequently referred to as "cannabis legalization" or "legalization") took place in Canada in October 2018. One of the federal government's stated goals with cannabis legalization was to protect Canadian youth from cannabis-related harms. The main objective of this narrative review is to describe the impact of cannabis legalization on Canadian youth. To that end, we discuss the regulation of the Canadian cannabis market, outline changes in the epidemiology and parameters of cannabis use (modes of use, potency of cannabis) among youth, and discuss prevention and education initiatives related to cannabis. The Canadian model differs from other jurisdictions that legalized recreational cannabis use, especially with regard to a higher degree of government regulation of the cannabis market. Another difference is the development and endorsement of lower-risk cannabis use guidelines to educate the public and health professionals. The results available for this review cover only 3 years post-legalization. Cannabis legalization in Canada brought an apparent increase in use among Canadian older than 25. However, results for youth are mixed, with the majority of studies showing no pronounced increase. Notably, the trend of a decrease in adolescents' cannabis use seen pre-legalization may have reversed. Emerging evidence also suggests that cannabis-related hospitalizations and emergency department visits among Canadian youth may have increased due to cannabis legalization. Data about changes in the age of initiation, the influence of legalization on sex and gender, and race/ethnicity are limited, with evidence suggesting that the age of initiation slightly increased. So far, there is limited data about the impact of cannabis legalization on Canadian youth. Further long-term monitoring and research to assess the effects of cannabis legalization on Canadian youth.