An overview of select cannabis use and supply indicators pre- and post-legalization in Canada

Predictors of Change in Cannabis Use Status from Pre- to Post-Recreational Cannabis Legalization in Canada: Evidence from a Two-Wave Longitudinal National Survey

Objective

In October 2018, the Government of Canada legalized cannabis for recreational use nationwide. The effects of legalization on cannabis use have been primarily assessed through cross-sectional surveys.

Method

In the present study, a two-wave longitudinal design was used to explore potential demographic, substance use and behavioral addiction, and mental health predictors of change in cannabis use status following legalization. Canadian online panelists (18+) were initially surveyed about their gambling and substance use in 2018 (i.e., before cannabis legalization). From the original sample, 4,707 (46.2%) were retained in the follow-up survey one year later, post-cannabis legalization. These respondents were the focus of the present study.

Results

When queried about how legalization would impact their use, 61.8% said, 'I'll never use it', 21.1% stated "I'll use it about the same as I do now," 10.3% indicated, "I may try it for the first time," 5.0% answered, "I'll use it more," and 1.9% responded that, "I'll use it less." Consistent with these sentiments, within the retained sample there was a modest but significant increase in cannabis use from baseline (18.4%) to follow-up (26.1%). Regressions established that younger age, being male, substance use, tobacco or e-cigarette use, problematic gambling, and stated intention to use cannabis were predictors of later cannabis use.

Conclusions

This national cohort design indicates that cannabis use appears to have increased in Canada following legalization. The present study makes a unique contribution by also identifying variables that statistically forecast movement toward and away from cannabis use.

Examining the Potential Impact of Recreational Cannabis Legalization on Individuals Receiving Treatment for Substance Use Disorder: An Interrupted Time Series Study in Guelph, Ontario, Canada

Objective

The present research evaluated the impact of legalizing recreational cannabis among individuals with substance use disorders (SUDs) who may already use cannabis at high rates.

Method

Using an interrupted time series study design, we evaluated the potential impact of legalizing recreational cannabis among individuals seeking treatment for SUD within a hospital-based treatment setting in Guelph, Ontario. We examined 2,925 individuals who entered an inpatient SUD treatment program between April 2017 and December 2021. We performed segmented regression analyses using both the date of cannabis legalization and the date of edibles legalization as the interruption time point. We also performed stratified analyses to examine potential sex differences.

Results

We found no significant changes in the frequency of cannabis use using either of the interruption time points. However, among the subsample who had used cannabis, there was evidence of increasing CUD severity post-legalization of edibles, as well as an overall decreasing trend in readiness to quit over time. Stratified analyses also suggested possible sex differences in frequency of cannabis use, CUD severity, and readiness to quit.

Conclusions

Results point to some small but potentially important impacts of recreational cannabis legalization that may only continue with time. Nevertheless, there is a need to continue to monitor cannabis use trends over time to understand any potential lagged effects.

Reducing the harms of cannabis use in youth post-legalization: insights from Ontario youth, parents, and service providers

BACKGROUND

Canada has one of the highest prevalence of cannabis use globally, particularly among young adults aged 20-24 (50%) and youth aged 16-19 (37%). In 2018, Canada legalized recreational cannabis with the aim of protecting youth by restricting their access and raising public awareness of health risks. However, there has been limited qualitative research on the perceptions of harms associated with youth cannabis use since legalization, which is crucial for developing effective harm reduction strategies. This qualitative study examined perceptions of cannabis use among youth from the perspectives of youth, parents, and service providers. We explored how participants described the perceived risks or harms associated with youth cannabis use, as well as how they described their own and others' approaches to reducing cannabis-related risks and harms.

METHODS

This qualitative study used a community-based participatory research approach in partnership with Families for Addiction Recovery (FAR), a national charity founded by parents of youth and young adults with addiction issues. Virtual semi-structured interviews were conducted, and the data were analyzed using thematic analysis.

RESULTS

The study included 88 participants from three key groups (n = 31 youth, n = 26 parents, n = 31 service providers). Two main themes emerged regarding perceived risks or harms associated with cannabis use: (1) concerns about cannabis-related risks and harms, including addiction, brain development, impact on family, and various adverse effects on areas such as motivation, concentration, finances, employment, education, physical and mental health; and (2) minimization of risks and harms, featuring conflicting messages, normalization, and perceptions of cannabis being less harmful than other substances. Additionally, two themes related to harm reduction approaches were identified: (1) implementation of harm reduction, and (2) challenges in implementing a harm reduction approach. Specific challenges for each participant group were noted, along with structural barriers such as unavailable and inaccessible services, easy access to cannabis, inadequate public education, and insufficient information on lower-risk cannabis use guidelines.

CONCLUSIONS

Youth cannabis use is a significant public health concern that requires a multi-pronged approach. Developing youth-centered harm reduction strategies that recognize the developmental needs and vulnerabilities of youth, as well as the important role of families, is imperative.

Decriminalizing and Legalizing Cannabis for Clinical Benefits in Malaysia: Perspective Among Pharmacists (A Qualitative Study)

Cannabis, often criticized, has active compounds that indicate multiple medical benefits. However, before the potential decriminalization and legalization of medical cannabis, pharmacists play a crucial role in the decision-making for personalized therapy and evidence-based medicine. This study investigates pharmacists' perspectives on medical cannabis, covering medical use, societal impact, research, legality, and regulation. This study was conducted through semi-structured interviews with pharmacists from different sectors. Interviews were conducted with 16 pharmacists, with 4 from each sector: industry, academia, community, and hospital. There was a consensus on the need for streamlined research before potential decriminalization and legalization of cannabis, highlighting concerns about abuse and misuse despite its benefits. With that in mind, all participants agree that there is a need to update the current legislation and regulations to better control the use and distribution of medical cannabis. Several participants also called to attention that education plays an important role in the potential decriminalization of medical cannabis, with cannabis-related stigma being a potential deterrent for not only the public but also healthcare professionals. As medical cannabis is a new subject in Malaysia, this study could ignite further multidisciplinary human-related research with strict regulations which will ultimately result in evidence-based medicine.

Impact of Legalization on Cannabis Use, Attitudes, and Purchasing Preferences: A Repeated Cross-Sectional Survey of Canadian Young Adults

Objective

The Government of Canada legalized recreational cannabis use in October of 2018 with the implementation of the Cannabis Act. The act aimed to reduce the illicit cannabis market, improve consumer health outcomes, and reduce youth access to cannabis. However, little is known about the attitudes and behaviors of young adults, who have been shown to have a high prevalence of cannabis use, towards cannabis after legalization.

Method

In this descriptive study, we examined cannabis use, attitudes, and purchasing preferences among Canadian university-attending young adults both before and after the legalization of cannabis. Participants were recruited from a large Canadian university from 2017 to 2021.

Results

Our findings showed that there was an increase in cannabis use immediately following legalization that subsequently decreased in later years. Additionally, attitudes about the legalization of cannabis became more favorable in later years (following legalization), particularly among those who did not use cannabis. Most young adults were also keen to purchase cannabis from a government-owned store before legalization. However, with the exception of past-month consumers, this preference decreased substantially following legalization.

Conclusions

The current research adds to the knowledge base about changes in cannabis-related attitudes and use after legalization and focuses on a key population - young adults.

Understanding youth and young adult cannabis use in Canada post-legalization: a scoping review on a public health issue

BACKGROUND

Canada legalized recreational cannabis in 2018, and one of the primary objectives of the Cannabis Act was to protect youth by reducing their access to cannabis and providing public education. Canada has the highest prevalence of cannabis use worldwide, particularly among youth and young adults under the age of 25. Cannabis use is linked with many adverse effects for youth and young adults including psychosis, anxiety, depression, respiratory distress, cannabinoid hyperemesis syndrome, and impaired cognitive performance. Despite the high prevalence of cannabis use and the evolution of policies in Canada and globally, significant knowledge and research gaps remain regarding youth and young adult cannabis use. The aim of this scoping review is to map the extent, nature, and range of evidence available on youth and young adult cannabis use in Canada since its legalization, in order to strengthen policies, services, treatments, training, and public education strategies.

METHODS

Using a scoping review framework developed by Arksey and O'Malley, along with the PRISMA-ScR guidelines, we conducted a rigorous search in five academic databases: MEDLINE, Embase, APA PsycINFO, CINAHL and Web of Science Core Collection. We included empirical studies that collected data in Canada after the legalization of recreational cannabis (October 2018) and focused on youth or young adults < 30. Two reviewers independently screened articles in two stages and extracted relevant information from articles meeting the inclusion criteria.

RESULTS

Of the 47 articles meeting our inclusion criteria, 92% used quantitative methods, 6% were qualitative, and 2% used a mixed-methods approach. Over two-thirds (68%) used secondary data. These studies were categorized into six focus areas: (1) prevalence, patterns, and trends, (2) cannabis-related injuries and emergency department (ED) visits, (3) rates and patterns during the pandemic, (4) perceptions of cannabis use, (5) prevention tools, and (6) cannabis-related offenses. Key findings from the studies reviewed include an increase in cannabis use among 18-24-year-olds post-legalization, with mixed results for youth under 18. ED visits for intentional and unintentional cannabis-related injuries have increased in young children and teens. Perception studies show a mix of concern and normalization of cannabis use. Though limited, prevention studies are promising in raising awareness. A decline in cannabis-related offenses was noted by one study. The review highlights several research gaps, including the need for more qualitative data, disaggregation of demographic data, intervention research, and comprehensive studies on the physical and mental health impacts of cannabis use among youth and young adults.

CONCLUSION

Maintaining a public health approach is critical, with a focus on reducing the high prevalence of cannabis use among youth and young adults. This involves implementing prevention strategies to minimize harms, enhancing public education, minimizing commercialization, reducing youth access to cannabis, promoting guidelines for lower-risk cannabis use and harm reduction strategies, and increasing training for healthcare providers.

Navigating the Grey Zone: The Impact of Legislative Frameworks in North America and Europe on Adolescent Cannabis Use-A Systematic Review

OBJECTIVES

This paper aims to systematically review the impact of legislative framework changes in North America and Europe on adolescent cannabis use. It not only seeks to examine the prevalence of adolescent marijuana use following legislative changes but also to identify the driving forces behind fluctuations in use and to address the gaps left by previous studies.

METHODS

A systematic literature review was conducted in selected databases. After screening English-language publications dating from 2013 to 2023 (n = 453 studies), 24 met the inclusion criteria. Articles were considered if they analyzed the impact of legislative changes on adolescent cannabis use in countries across North America and Europe.

SYNTHESIS

The overall findings suggest an inconsistency regarding the prevalence of cannabis use among youth and adolescents following policy changes. The effects of modifications in cannabis policies on marijuana consumption are complex and influenced by various factors. These include the details of legislation, societal perspectives, enforcement methods, socioeconomic status, and cultural background.

CONCLUSIONS

The results of this analysis reveal a nuanced reality. Although research suggests a rise in cannabis use after legalization, there are variations in the outcomes observed. This highlights the significance of considering context and demographics. Moreover, studies shed light on how specific policy changes, such as depenalization, can affect cannabis 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.

Unhealthy behaviors associated with mental health disorders: a systematic comparative review of diet quality, sedentary behavior, and cannabis and tobacco use

Background

There are well-established literatures documenting the associations between mental disorders and unhealthy behaviors such as poor diet quality, sedentary behavior, and cannabis and tobacco use. Few studies have attempted to understand the respective findings in light of each other, however.

Objective

The purpose of this review was to assemble comparable data for each behavior-disorder association and assess the associations in terms of their overall strength. The review aimed to include a representative, but not exhaustive, range of studies that would allow for explorative comparisons.

Methods

Eligible studies were identified via Pubmed searches and citation searching, restricted to publications no older than 2015 written in English. To obtain comparable data, only studies that reported findings as odds ratios were included, and risk of bias related to study samples, behavioral measurement disparities, and control variables was assessed via sensitivity analyses. Findings for each disorder were compared on the basis of different measures of central tendency.

Results

From 3,682 records, 294 studies were included. The review found evidence of associations between each of the four unhealthy behaviors and psychosis, depression, anxiety, bipolar disorder, attention-deficit/hyperactivity disorder (ADHD), and post-traumatic stress disorder (PTSD), while personality disorder was only investigated in relation to cannabis and tobacco use. In overall comparison, the associations were generally of similar strength, and only the association between cannabis use and personality disorder was exceptional in terms of being significantly stronger than its counterparts across disorders and across behaviors. Analyses of bias risk identified some influence from behavioral measurement disparities and lack of adequate statistical control, but findings were generally robust across a range of sensitivity analyses.

Conclusion

This explorative and comparative review found that poor diet quality, sedentary behavior, and cannabis and tobacco use are about equally strongly associated with a range of different mental disorders. Given the general nature of these associations, we should probably understand them to reflect a general and shared etiology. However, the findings in this review should be regarded as tentative until confirmed by more comprehensive investigations.

Impact of non-medical cannabis legalization with market restrictions on health service use and incident cases of psychotic disorder in Ontario, Canada

BACKGROUND

Cannabis is a risk factor in the onset and persistence of psychotic disorders. There is concern that non-medical cannabis legalization in Canada may have population-level impacts on psychotic disorders. We sought to examine changes in health service use and incident cases of psychotic disorder following cannabis legalization, during a period of tight restrictions on retail stores and product types.

METHODS

We conducted a cross-sectional interrupted time-series analysis using linked population-based health administrative data from Ontario (Canada) from January 2014 to March 2020. We identified psychosis-related outpatient visits, emergency department visits, hospitalizations, and inpatient length of stay, as well as incident cases of psychotic disorders, among people aged 14 to 60 years.

RESULTS

We did not find evidence of increases in health service use or incident cases of psychotic disorders over the short-term (17 month) period following cannabis legalization. However, we found clear increasing trends in health service use and incident cases of substance-induced psychotic disorders over the entire observation window (2014-2020).

CONCLUSION

Our findings suggest that the initial period of tight market restriction following legalization of non-medical cannabis was not associated with an increase in health service use or frequency of psychotic disorders. A longer post-legalization observation period, which includes expansion of the commercial cannabis market, is needed to fully understand the population-level impacts of non-medical cannabis legalization; thus, it would be premature to conclude that the legalization of non-medical cannabis did not lead to increases in health service use and incident cases of psychotic disorder.

Cannabis Use Among Adults in Cigarette Smoking Cessation Treatment in Ontario, Canada: Prevalence and Association With Tobacco Cessation Outcome, 2015-2021

Objectives. To examine cannabis use prevalence and its association with tobacco cessation among adults enrolled in cigarette smoking cessation treatment before and after Canada legalized recreational cannabis in October 2018. Methods. The sample comprised 83 206 adults enrolled in primary care-based cigarette smoking cessation treatment between 2015 and 2021 in Ontario, Canada. Past-30-day cannabis use was self-reported at enrollment and cigarette smoking abstinence at 6-month follow-up. Results. Past-30-day prevalence of cannabis use increased from 20.2% in 2015 to 37.7% in 2021. The prevalence increased linearly both before and after legalization. Cannabis and tobacco co-use was associated with lower odds of self-reported cigarette smoking abstinence at 6-month follow-up than tobacco use only (24.4% vs 29.3%; odds ratio [OR] = 0.78; 95% confidence interval [CI] = 0.75, 0.81). This association was attenuated after adjustment for covariates (OR = 0.93; 95% CI = 0.89, 0.97) and weakened slightly over time. Conclusions. Cannabis use prevalence almost doubled from 2015 to 2021 among primary care patients in Ontario seeking treatment to quit cigarettes and was associated with poorer quit outcomes. Further research into the impact of cannabis policy on cannabis and tobacco co-use is warranted to mitigate harm. (Am J Public Health. 2024;114(1):98-107. https://doi.org/10.2105/AJPH.2023.307445).

Youth perception of difficulty accessing cannabis following cannabis legalization and during the early and ongoing stages of the COVID-19 pandemic: repeat cross-sectional and longitudinal data from the COMPASS study

BACKGROUND

Very little research has examined how perceptions of cannabis access among underage youth in Canada have changed since cannabis was legalized and since the onset of the COVID-19 pandemic. As such, this paper examines the effect of the early and ongoing stages of the COVID-19 pandemic period on youth perceptions of cannabis access over time since the onset of the Cannabis Act in 2018 in a large sample of Canadian youth.

METHODS

Using data from the COMPASS study (T1:2018/19, T2:2019/20, T3:2020/21), we used both repeat cross-sectional data [T1 (n = 38,890), T2 (n = 24,109), and T3 (n = 22,795)] to examine overall trends in perceptions of cannabis access, and sequential cohort longitudinal data [n = 4,677 students linked from T1 to T3] to examine the differential changes in perceptions of cannabis access among students over time.

RESULTS

In the cross-sectional sample, the frequency of students reporting that cannabis was easy to access decreased by 26.7% from T1 (51.0%) to T3 (37.4%), although respondents who have used cannabis were more likely to report access was easy. In the longitudinal sample, perceptions of cannabis access being easy increased over time, especially among cannabis users. Perceived ease of access appears to have been slightly impeded during the initial pandemic period but rebounded during the ongoing pandemic period.

CONCLUSIONS

While the prevalence of youth reporting that cannabis is easy to access has declined since legalization and throughout the early and ongoing pandemic periods, a substantial number of underage youth continue to report that cannabis is easy to access. This suggest that there is an ongoing need for continued cannabis control efforts to address this issue.

Workplace and non-workplace cannabis use and the risk of workplace injury: Findings from a longitudinal study of Canadian workers

OBJECTIVES

Findings of previous studies examining the relationship between cannabis use and workplace injury have been conflicting, likely due to methodological shortcomings, including cross-sectional designs and exposure measures that lack consideration for timing of use. The objective was to estimate the association between workplace cannabis use (before and/or at work) and non-workplace use and the risk of workplace injury.

METHODS

Canadian workers participating in a yearly longitudinal study (from 2018 to 2020) with at least two adjacent years of survey data comprised the analytic sample (n = 2745). The exposure was past-year workplace cannabis use (no past-year use, non-workplace use, workplace use). The outcome was past-year workplace injury (yes/no). Absolute risks and relative risks (RR) with 95% confidence intervals (CIs) were estimated between workplace and non-workplace cannabis use at one time point and workplace injury at the following time point. Models were adjusted for personal and work variables and were also stratified by whether respondents' jobs were safety-sensitive.

RESULTS

Compared to no past-year cannabis use, there was no difference in workplace injury risk for non-workplace cannabis use (RR 1.09, 95%CI 0.83-1.44). However, workplace use was associated with an almost two-fold increased risk of experiencing a workplace injury (RR 1.97, 95%CI 1.32-2.93). Findings were similar for workers in safety-sensitive and non-safety-sensitive work.

CONCLUSION

It is important to distinguish between non-workplace and workplace use when considering workplace safety impacts of cannabis use. Findings have implications for workplace cannabis use policies and substantiate the need for worker education on the risks of workplace cannabis use.

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.

Uptake of SARS-CoV-2 vaccination among structurally-marginalized people who use drugs in Vancouver, Canada

We sought to evaluate the rates and predictors of SARS-CoV-2 vaccination among members of a structurally-marginalized population of people who use drugs (PWUD) during a targeted, community-wide, vaccination campaign in Vancouver, Canada. Interviewer-administered data were collected from study participants between June 2021 and March 2022. Generalized estimating equation analysis was used to identify factors associated with SARS-CoV-2 vaccine uptake, ascertained through a province-wide vaccine registry. Among 223 PWUD, 107 (48.0%) reported receipt of at least two SARS-CoV-2 vaccine doses at baseline and this increased to 151 (67.7%) by the end of the study period. Using social media as a source of vaccine information was negatively associated with SARS-CoV-2 vaccine uptake (Adjusted odds ratio [AOR] 0.27, 95% confidence interval [CI] 0.09-0.81) and HIV seropositivity (AOR 2.68, 95% CI 1.12-6.39) and older age (AOR 1.27, 95% CI 1.07-1.51) were positively associated with SARS-CoV-2 vaccine uptake. These findings suggest that the targeted vaccination campaign in Vancouver may be an effective model to promote SARS-CoV-2 vaccination in other jurisdictions. However, using social media as a source of vaccine information likely reduced SARS-CoV-2 vaccine uptake in PWUD arguing for further efforts to promote accessible and evidence-based vaccine information among marginalized populations.

Cannabis Use Frequency and Cannabis-Related Consequences in High-Risk Young Adults Across Cannabis Legalization

Importance

A key concern about recreational cannabis legalization is increases in use and adverse consequences, particularly among young adults (aged 18-29 years) who have the highest prevalence of cannabis use, and especially in higher-risk, more vulnerable young adults. However, few longitudinal studies have examined patterns of cannabis consumption in high-risk young adults over the course of legalization.

Objective

To examine changes in cannabis use frequency and cannabis-related consequences over recreational cannabis legalization in Canada in a longitudinal sample of high-risk young adults.

Design, Setting, and Participants

Longitudinal observational cohort study following young adults in Ontario, Canada, aged 19.5 to 23.0 years who reported regular heavy episodic drinking (65% past-month cannabis use) at enrollment. Participants were surveyed every 4 months for 3 years between February 2017 and February 2020 (3 prelegalization waves, 4 postlegalization waves). Data were analyzed from March to May 2023.

Exposures

Recreational cannabis legalization in Canada and 4 potential moderators of change: sex, income, education, and prelegalization cannabis use frequency.

Main Outcomes and Measures

Cannabis use frequency and cannabis-related adverse consequences.

Results

In a cohort of 619 high-risk young adults (baseline mean [SD] age, 21.0 [1.2] years; 346 female participants [55.9%]), omnibus model testing revealed significant overall decreases in both cannabis use frequency (F = 2.276, 3000.96; P = .03) and cannabis-related consequences (F = 10.436, 3002.21; P < .001) over time, but these changes were substantially moderated by prelegalization frequency (frequency: F = 7.5224, 3021.88; P < .001; consequences: F = 7.2424, 2986.98; P < .001). Follow-up tests showed individuals who used cannabis more frequently prelegalization significantly decreased their use and cannabis-related consequences postlegalization. In contrast, individuals who did not use cannabis prelegalization exhibited a small magnitude increase in frequency over time but nonsignificant changes in cannabis-related consequences. Sex, income, and education did not moderate changes over time.

Conclusions and Relevance

In this cohort study of high-risk young adults, individuals using cannabis frequently prelegalization showed significant reductions in use and consequences over time, reflecting an aging out pattern. Small increases in use among participants with no prelegalization use were observed over time, but without parallel changes in cannabis-related consequences. The results did not reveal substantive adverse near-term outcomes across the legalization period, although a within-participants design cannot rule out the possibility of alternative trajectories in the absence of legalization.

Patterns of problematic cannabis use in Canada pre- and post-legalisation: Differences by neighbourhood deprivation, individual socioeconomic factors and race/ethnicity

INTRODUCTION

The legalisation of cannabis in Canada in 2018, and subsequent increase in prevalence of use, has generated interest in understanding potential changes in problematic patterns of use, including by socio-demographic factors such as race/ethnicity and neighbourhood deprivation level.

METHODS

This study used repeat cross-sectional data from three waves of the International Cannabis Policy Study web-based survey. Data were collected from respondents aged 16-65 prior to cannabis legalisation in 2018 (n = 8704), and post-legalisation in 2019 (n = 12,236) and 2020 (n = 12,815). Respondents' postal codes were linked to the INSPQ neighbourhood deprivation index. Multinomial regression models examined differences in problematic use by socio-demographic and socio-economic factors and over time.

RESULTS

No evidence of a change in the proportion of those aged 16-65 in Canada whose cannabis use would be classified as 'high risk' was noted from before cannabis legalisation (2018 = 1.5%) to 12 or 24 months after legalisation (2019 = 1.5%, 2020 = 1.6%; F = 0.17, p = 0.96). Problematic use differed by socio-demographic factors. For example, consumers from the most materially deprived neighbourhoods were more likely to experience 'moderate' vs 'low risk' compared to those living outside deprived neighbourhoods (p < 0.01 for all). Results were mixed for race/ethnicity and comparisons for high risk were limited by small sample sizes for some groups. Differences across subgroups were consistent from 2018 to 2020.

DISCUSSION AND CONCLUSIONS

The risk of problematic cannabis use does not appear to have increased in the 2 years following cannabis legalisation in Canada. Disparities in problematic use persisted, with some racial minority and marginalised groups experiencing higher risk.

Cannabis use to manage opioid cravings among people who use unregulated opioids during a drug toxicity crisis

BACKGROUND

Accumulating evidence has indicated that cannabis substitution is often used as a harm reduction strategy among people who use unregulated opioids (PWUO) and people living with chronic pain. We sought to investigate the association between cannabis use to manage opioid cravings and self-reported changes in opioid use among structurally marginalized PWUO.

METHODS

The data were collected from a cross-sectional questionnaire administered to PWUO in Vancouver, Canada. Binary logistic regression was used to analyze the association between cannabis use to manage opioid cravings and self-reported changes in unregulated opioid use.

RESULTS

A total of 205 people who use cannabis and opioids were enrolled in the present study from December 2019 to November 2021. Cannabis use to manage opioid cravings was reported by 118 (57.6%) participants. In the multivariable analysis, cannabis use to manage opioid cravings (adjusted Odds Ratio [aOR] = 2.13, 95% confidence interval [CI]: 1.07, 4.27) was significantly associated with self-reported reductions in opioid use. In the sub-analyses of pain, cannabis use to manage opioid cravings was only associated with self-assessed reductions in opioid use among people living with moderate to severe pain (aOR = 4.44, 95% CI: 1.52, 12.97). In the sub-analyses of males and females, cannabis use to manage opioid cravings was only associated with self-assessed reductions in opioid use among females (aOR = 8.19, 95% CI: 1.20, 55.81).

CONCLUSIONS

These findings indicate that cannabis use to manage opioid cravings is a prevalent motivation for cannabis use among PWUO and is associated with self-assessed reductions in opioid use during periods of cannabis use. Increasing the accessibility of cannabis products for therapeutic use may be a useful supplementary strategy to mitigate exposure to unregulated opioids and associated harm during the ongoing drug toxicity crisis.

Evaluating the Supporting Evidence of Medical Cannabis Claims Made on Clinic Websites: Cross-Sectional Study

BACKGROUND

Since the legalization of medical cannabis in Canada in 2013, prescription of cannabis for medical purposes has become commonplace and a multibillion dollar industry has formed. Much of the media coverage surrounding medical cannabis has been positive in nature, leading to Canadians potentially underestimating the adverse effects of medical cannabis use. In recent years, there has been a large increase in clinic websites advertising the use of medical cannabis for health indications. However, little is known about the quality of the evidence used by these clinic websites to describe the effectiveness of cannabis used for medical purposes.

OBJECTIVE

We aimed to identify the indications for medical cannabis reported by cannabis clinics in Ontario, Canada, and the evidence these clinics cited to support cannabis prescription.

METHODS

We conducted a cross-sectional web search to identify all cannabis clinic websites within Ontario, Canada, that had physician involvement and identified their primary purpose as cannabis prescription. Two reviewers independently searched these websites to identify all medical indications for which cannabis was promoted and reviewed and critically appraised all studies cited using the Oxford Centre for Evidence-Based Medicine Levels of Evidence rubric.

RESULTS

A total of 29 clinics were identified, promoting cannabis for 20 different medical indications including migraines, insomnia, and fibromyalgia. There were 235 unique studies cited on these websites to support the effectiveness of cannabis for these indications. A high proportion (36/235, 15.3%) of the studies were identified to be at the lowest level of evidence (level 5). Only 4 clinic websites included any mention of harms associated with cannabis.

CONCLUSIONS

Cannabis clinic websites generally promote cannabis use as medically effective but cite low-quality evidence to support these claims and rarely discuss harms. The recommendation of cannabis as a general therapeutic for many indications unsupported by high-quality evidence is potentially misleading for medical practitioners and patients. This disparity should be carefully evaluated in context of the specific medical indication and an individualized patient risk assessment. Our work illustrates the need to increase the quality of research performed on the medical effects of cannabis.

Exploring Differences in Daily Vaping of Nicotine and Cannabis among People Who Use Drugs in New Zealand

Background: Little is known about daily vaping of different substances, particularly cannabis. Aim: To explore daily vaping of cannabis and nicotine products in a sample of people who use drugs in New Zealand. Method: The online New Zealand Drug Trends convenience survey (N = 23,500) was promoted to those aged 16+ via a targeted Facebook™ campaign, with 9,042 reporting vaping in the past six months. Multivariate logistic regression models were fitted to identify predictors of daily vaping of: (i) nicotine e-liquids, (ii) no-nicotine e-liquids, (iii) cannabis e-liquids/oils, (iv)cannabis herb. Results: Forty-two percent of past 6-month vapers used a vaporizing device "daily or near daily" (n = 3,508). Nicotine was most common substance used by daily vapers (96%), followed by dry herb cannabis (12%), no-nicotine e-liquids (10%) and cannabis e-liquid (6%). Daily vaping of no-nicotine e-liquids was associated with abstinence from tobacco use. Frequency of cannabis use was negatively correlated with daily vaping of nicotine liquids and positively correlated with daily vaping of no-nicotine and herbal cannabis. Younger age strongly predicted daily vaping of nicotine and no-nicotine liquids, but the reverse association was observed for daily vaping of herbal cannabis. Māori were less likely to daily vape cannabis herb than NZ Europeans. Daily vaping of both cannabis e-liquid and cannabis herb was associated with medicinal cannabis use. Conclusion: Daily vapers of nicotine and cannabis differed by several characteristics. Younger age group is at risk of daily vaping nicotine and non-nicotine, while herbal cannabis vaping is associated with older and medicinal use, suggesting a need for a nuanced vape policy response.

The impact of legal cannabis availability on cannabis use and health outcomes: A systematic review

BACKGROUND

For alcohol, regulating availability is an effective way to reduce consumption and harm. Similarly, the higher availability of medical cannabis dispensaries has been linked to increased cannabis consumption and harm. For recreational cannabis markets, such a link is suspected but still poorly understood.

METHODS

A systematic literature review (PROSPERO registration number 342357) was conducted on 1 July 2022 in common libraries (Medline, Web of Science, PsycInfo, Psyndex, CINAHL, Embase, SCOPUS, Cochrane) for publications since 2012. Studies linking variations in the availability of legal cannabis products to behavioral outcomes (cannabis use or related health indicators) were included, while studies focusing solely on the legalization of medical cannabis were excluded. The risk of bias was assessed using an adapted version of the Newcastle-Ottawa-Scale.

RESULTS

After screening n = 6,253 studies, n = 136 were selected for full-text review, out of which n = 13 met the inclusion criteria, reporting on n = 333,550 study participants and n = 855,630 presentations to emergency departments. All studies were conducted in North America, with the majority from Western US states. Using longitudinal (n = 1), cross-sectional (n = 4), or repeated cross-sectional (n = 8) study designs, an increased availability of legal cannabis was linked to increased current cannabis use and health-related outcomes (vomiting, psychosis, or cannabis-involved pregnancies), regardless of the indicator employed to measure availability (proximity or density) among both adults and adolescents. The positive correlation between cannabis availability and consumption is most pronounced among those groups who have been less exposed to cannabis before legalization. The association between the availability of legal cannabis and risky use indicators was less consistent.

CONCLUSIONS

Groups who have been least exposed to cannabis before legalization may be most susceptible to increased availability. In jurisdictions with legal cannabis markets, restrictions on the number of legal cannabis retailers, especially in densely populated areas, appear warranted.

Recommendations for Reducing the Risk of Cannabis Use-Related Adverse Psychosis Outcomes: A Public Mental Health-Oriented Evidence Review

Objective: Cannabis use is increasingly normalized; psychosis is a major adverse health outcome. We reviewed evidence on cannabis use-related risk factors for psychosis outcomes at different stages toward recommendations for risk reduction by individuals involved in cannabis use. Methods: We searched primary databases for pertinent literature/data 2016 onward, principally relying on reviews and high-quality studies which were narratively summarized and quality-graded; recommendations were developed by international expert consensus. Results: Genetic risks, and mental health/substance use problem histories elevate the risks for cannabis-related psychosis. Early age-of-use-onset, frequency-of-use, product composition (i.e., THC potency), use mode and other substance co-use all influence psychosis risks; the protective effects of CBD are uncertain. Continuous cannabis use may adversely affect psychosis-related treatment and medication effects. Risk factor combinations further amplify the odds of adverse psychosis outcomes. Conclusions: Reductions in the identified cannabis-related risks factors-short of abstinence-may decrease risks of related adverse psychosis outcomes, and thereby protect cannabis users' health.

Effects of cannabis regulation in Switzerland: Study protocol of a randomized controlled trial

Background

Cannabis is the most widely used illicit substance. Various countries have legalized cannabis for recreational use. Evidence on the health effects of cannabis regulation remains unclear and is mainly based on observational studies. To date, there is no randomized controlled study evaluating the impact of cannabis regulation for recreational use compared to the illicit market on relevant health indicators. The present study ("Weed Care") is the first to evaluate the impact of regulated cannabis access in pharmacies versus a waiting list control group representing the illicit market on problematic cannabis use as well as on mental and physical health.

Methods

The study is divided into two parts-a randomized controlled study of 6 months followed by an observational study of 2 years. Participants (N = 374) are randomly assigned to either the experimental group with access to legal cannabis in pharmacies or to the waiting list control group representing the current legal framework in Switzerland, namely the illicit market. After 6 months, all participants will have access to legal cannabis for the following 2 years (observational study). The primary outcome is problematic cannabis use as measured with the Cannabis Use Disorders Identification Test-Revised (CUDIT-R). Secondary outcomes are cannabis use patterns, mental disorders (e.g., depression, anxiety, and psychosis) and physical health (e.g., respiratory symptoms). Primary and secondary outcomes will be assessed online every 6 months. The study is approved by the responsible ethics committee as well as by the Swiss Federal Office of Public Health.

Discussion

Findings from this study may provide a scientific basis for future discussions about addiction medicine and cannabis policy in Switzerland.

Clinical Trial Registration

ClinicalTrials.gov (NCT05522205). https://clinicaltrials.gov/ct2/show/NCT05522205.

Access to legal cannabis market in Canada over the four years following non-medical cannabis legalisation

INTRODUCTION

An increasing number of countries are inthe process of legalising non-medical cannabis. We described how the legal market has changed over the first 4 years following legalisation in Canada.

METHODS

We collected longitudinal data on operating status and location of all legal cannabis stores in Canada for the first 4 years following legalisation. We examined per capita stores and sales, store closures, and the drive time between stores and each neighbourhood in Canada. We compared measures between public and private retail systems.

RESULTS

Four years after legalisation, there were 3305 cannabis stores open in Canada (10.6 stores per 100,000 individuals aged 15+ years). Canadians spent $11.85CAD a month on cannabis per individual aged 15+ years, and 59% of neighbourhoods were within a 5-minute drive of a cannabis store. Over 4 years, per capita stores and per capita sales increased each year by an average of 122.3% and 91.7%, respectively, with larger increases in private versus public systems (4.01 times greater for per capita stores and 2.46 times greater for per capita sales). The annual increase in per capita stores and sales during the first 3 years was 6.0 and 15.5 times greater, respectively, than the increase in the fourth year following legalisation. Over 4 years, 7% of retail store locations permanently closed.

DISCUSSION AND CONCLUSION

The legal cannabis market in Canada expanded enormously over the first 4 years following legalisation, with considerable variation in access between jurisdictions. The rapid retail expansion has implications for evaluation of health impacts of non-medical legalisation.

The international regime of drug control may violate the human right to life and security

Critics of the international regime of drug control have often pointed to its criminogenic effects, maintaining that drug criminalization gives rise to a profitable illicit drugs market which in turn sustains organized crime networks. Here I will expand upon this critique to argue that the violent crime resulting from the drug criminalization regime may constitute a violation of the human right to life and security. To support this argument, I will discuss the extent to which policy makers and the citizens who empower them may stand morally responsible for unintended but foreseeable consequences of the policies they implement. I will note that a north-south imbalance is at play: while the Global North has been the driving force behind the criminalization regime, the violent criminality entailed by the regime of drug control has impacted the Global South most strongly.

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.

Content Analysis of the Corporate Social Responsibility Practices of 9 Major Cannabis Companies in Canada and the US

IMPORTANCE

The cannabis industry has sought to normalize itself and expand its markets in the 21st century. One strategy used by companies to generate positive public relations is corporate social responsibility (CSR). It is critical to understand these efforts to influence the public and politicians given the risks of increased cannabis use.

OBJECTIVES

To analyze cannabis industry CSR behaviors, determine their characteristics, and compare their practices with those of the tobacco industry.

DESIGN, SETTING, AND PARTICIPANTS

This qualitative study of CSR activities conducted between January 1, 2012, and December 31, 2021, evaluated 9 of the 10 largest publicly traded cannabis companies in the US and Canada. Data were collected from August 1 to December 31, 2021. The 10th company was excluded because it engaged in cannabis-based pharmaceutical sales but not CSR. A systematic review of corporate websites and Nexis Uni was performed, resulting in collection of 153 news articles, press releases, and Web pages. Charitable and philanthropic actions were included. Themes were identified and interpreted using modified grounded theory.

MAIN OUTCOMES AND MEASURES

CSR activities and spending.

RESULTS

Nine major cannabis companies in the US and Canada engaged in CSR activities that encouraged increased consumption and targeted marginalized communities. Companies claimed these activities would mitigate the harms of cannabis prohibition, promote diversity, expand access to medical cannabis, and support charitable causes. They developed educational programs, sustainability initiatives, and voluntary marketing codes and used strategies similar to those used by tobacco companies to recruit public interest organizations as allies.

CONCLUSIONS AND RELEVANCE

These findings suggest that cannabis companies developed CSR strategies comparable to those used by the tobacco industry to influence regulation, suggesting that cannabis companies should be included when addressing commercial determinants of health.

Cannabis use and risks of respiratory and all-cause morbidity and mortality: a population-based, data-linkage, cohort study

INTRODUCTION

Although cannabis is frequently used worldwide, its impact on respiratory health is characterised by controversy.

OBJECTIVE

To evaluate the association between cannabis use and respiratory-related emergency room (ER) visits and hospitalisations.

METHODS

A retrospective, population-based, cohort study was carried out, linking health survey and health administrative data for residents of Ontario, Canada, aged 12-65 years, between January 2009 and December 2015. Individuals self-reporting cannabis use within the past year were matched to control individuals (people who reported never using cannabis, or used cannabis only once, and more than 12 months ago) in upwards of a 1:3 ratio on 31 different variables, using propensity score matching methods. Respiratory-related and all-cause ER visits or hospitalisations, and all-cause mortality, were evaluated up to 12 months following the index date.

RESULTS

We identified 35 114 individuals who had either used cannabis in the past year or were controls, of whom 6425 (18.3%) used cannabis in the past year. From this group, 4807 (74.8%) were propensity-score matched to 10 395 control individuals. In the propensity score matched cohort, there was no significant difference in odds of respiratory-related ER visit or hospitalisation between cannabis users and the control group (OR 0.91, 95% CI 0.77 to 1.09). Compared with control individuals, cannabis users had significantly increased odds of all-cause ER visit or hospitalisation (OR 1.22, 95% CI 1.13 to 1.31) and there was no significant difference with respect to all-cause mortality (OR 0.99, 95% CI 0.49 to 2.02).

CONCLUSIONS

Although no significant association was observed between cannabis use and respiratory-related ER visits or hospitalisations, the risk of an equally important morbidity outcome, all-cause ER visit or hospitalisation, was significantly greater among cannabis users than among control individuals. Therefore, cannabis use is associated with increased risk for serious adverse health events and its recreational consumption is not benign.

Considerations for Cannabinoids in Perioperative Care by Anesthesiologists

Increased usage of recreational and medically indicated cannabinoid compounds has been an undeniable reality for anesthesiologists in recent years. These compounds’ complicated pharmacology, composition, and biological effects result in challenging issues for anesthesiologists during different phases of perioperative care. Here, we review the existing formulation of cannabinoids and their biological activity to put them into the context of the anesthesia plan execution. Perioperative considerations should include a way to gauge the patient’s intake of cannabinoids, the ability to gain consent properly, and vigilance to the increased risk of pulmonary and airway problems. Intraoperative management in individuals with cannabinoid use is complicated by the effects cannabinoids have on general anesthetics and depth of anesthesia monitoring while simultaneously increasing the potential occurrence of intraoperative hemodynamic instability. Postoperative planning should involve higher vigilance to the risk of postoperative strokes and acute coronary syndromes. However, most of the data are not up to date, rending definite conclusions on the importance of perioperative cannabinoid intake on anesthesia management difficult.

Conceptualizing and considering Cannabis-Related "Harm-to-Others": The Role of Cannabis-Related Violence

Public health-oriented frameworks for cannabis use of control, including legalization, are evolving. Most frameworks aim to reduce cannabis-related health harms that materialize among users; there has been comparably limited focus on cannabis-related "harm-to-others". A longstanding issue for other psychoactive substances, and increasingly recognized form of cannabis-related harm-to-others involves violence/aggression. We briefly review relevant epidemiological and psycho-behavioral data related to cannabis-related violence and aggression, and discuss intervention prospects. Systematic review and other study data show a moderately positive association between cannabis use and perpetration of physical (including intimate-partner) violence, for example involving assault, aggression, and fighting; this risk may be further elevated by intensive use patterns. Such harms may involve injuries/deaths and contribute to the cannabis-related burden of disease. Within the contexts of public health-oriented frameworks for cannabis control, greater awareness and targeted interventions regarding the risk for exposure to violence related to cannabis use should be promoted in addition to protections for users' health.