Changes in modes of cannabis consumption pre- and post-legalization and their correlates among adults in Ontario, Canada: 2017-2022.

Background: Despite an increase in the varieties of cannabis products available for consumption, limited evidence is available about the patterns of cannabis consumption methods before and after legalization.Objectives: To examine the changes in modes of cannabis use and their correlates among adults in Ontario, Canada both prior to and following cannabis legalization in 2018.Methods: Data were utilized from the 2017 to 2022 Centre for Addiction and Mental Health's (CAMH) Monitor study, a repeated cross-sectional survey of adults 18 years of age and older (n = 2,665; 56% male). The surveys employed a regionally stratified sampling design using computer-assisted telephone interviews and web surveys. Multinomial regression was performed to examine different modes of cannabis use.Results: The exclusive use of cannabis through ingestion methods increased from 4.0% in 2017 to 16.6% in 2022 (p < .001). However, the exclusive use of inhalation-based cannabis decreased from 49.4% in 2017 to 25.5% in 2022 (p < .001). Relative to inhalation-based modes, adults were about five times more likely to use ingestion-based modes in 2020 [RRR = 4.65 (2.94-7.35)] and 2022 [RRR = 4.75 (2.99-7.55)] than in 2019, after accounting for sociodemographic factors.Conclusions: Ingestion-based cannabis use among adults increased fourfold between 2017 and 2022, a period during which recreational cannabis use was legalized in Canada. The increase was especially evident after the legalization of cannabis edibles.

Changes in medical cannabis use in Ontario, Canada (2014 to 2019): Trajectory of trends, medical authorization patterns and association with recreational cannabis legalization.

Objectives: We characterized trends in medical cannabis use; examined characteristics associated with medical cannabis use without medical authorization; and examined the association between recreational cannabis legalization and medical cannabis use in Ontario, Canada. Methods: Data were from a repeated, population-based, cross-sectional survey of adults (N = 19,543; 2014-2019). Cannabis use was categorized as either medical cannabis use, recreational cannabis use or no cannabis use. The analytical strategy included jointpoint regression, logistic regression and multinomial logistic regression. Results: Medical cannabis use increased from 4 % to 11 % (Annual Percentage Change [APC]: 25 %, 95 % Confidence Interval [CI]: 17 %-33 %) and recreational cannabis use increased from 9 % to 15 % (APC: 9 %, 95 % CI: 3 %-15 %) between 2014 and 2019. Being 18 to 29 years old compared with being 65+ years old was associated with an increased likelihood of medical cannabis use without medical authorization (Odds Ratio [OR]: 4.05, 95 % CI: 2.12-7.72), while being of fair or poor self-perceived health compared with excellent, very good or good self-perceived health (OR: 0.61, 95 % CI: 0.40-0.95) was associated with a decreased likelihood of medical cannabis use without medical authorization. Recreational cannabis legalization was associated with an increased likelihood of medical cannabis use compared with no cannabis use (OR: 1.48, 95 % CI: 1.19-1.85) and of recreational cannabis use compared with no cannabis use (OR: 1.35, 95 % CI: 1.11-1.65). Conclusions: Although medical cannabis use increased, it was largely used without medical authorization. Guidance and education that encourages medical usage under clinical supervision is recommended, and mitigation of known barriers to medical cannabis authorization.

The association between physical availability of cannabis retail outlets and frequent cannabis use and related health harms: a systematic review.

An increasing number of regions have or are considering legalising the sale of cannabis for adult use. Experience from tobacco and alcohol regulation has found that greater access to physical retail stores is positively associated with increased substance use and harm. Whether this association exists for cannabis is unclear. We completed a systematic review examining the association between cannabis retail store access and adverse health outcomes. We identified articles up until July 20, 2023 by searching four databases. We included studies examining the association between measures of cannabis store access and adverse outcomes: frequent or problematic cannabis use, healthcare encounters due to cannabis use (e.g., cannabis-induced psychosis), and healthcare encounters potentially related to cannabis (e.g., self-harm episodes). Results were compared by study design type, retail access measure, and by subgroups including: children, adolescents, young adults, adults, and pregnant individuals. This review was registered with PROSPERO (CRD42021281788). The search generated 5750 citations of which we included 32 studies containing 44 unique primary analyses (unique retail measure and outcome pairs). Studies come from 4 countries (United States, Canada, Netherlands and Uruguay). Among the included analyses, there were consistent positive associations between greater cannabis retail access and 1) increased healthcare service use or poison control calls directly due to cannabis (10/12 analyses; 83%) (2) increased cannabis use and cannabis-related hospitalization during pregnancy (4/4; 100%) and 3) frequent cannabis use in adults and young adults (7/11; 64%). There was no consistent positive association between greater cannabis retail and increased frequent cannabis use in adolescents (1/4; 25%), healthcare service use potentially related to cannabis (2/6; 33%) or increased adverse neonatal birth outcomes (2/7; 26.8%). There is a positive association between greater cannabis store access and increases in cannabis harm. In countries with legal cannabis, retail restrictions may reduce use and harm. Funding: Canadian Centre on Substance Use and Addiction (CCSA).

Effects of cannabis legalisation on patterns of cannabis consumption among adolescents in Ontario, Canada (2001-2019).

INTRODUCTION: Cannabis legalisation was enacted on 17 October 2018 in Canada. Accordingly, the effects of cannabis legalisation on patterns of cannabis consumption were examined among adolescents, including on cannabis initiation, any cannabis use, daily cannabis use and cannabis dependence. METHODS: Data from a biennial population-based, cross-sectional survey of students in Ontario were pooled in a pre-post design (2001-2019; N = 89,238). Participants provided self-reports of cannabis initiation, any cannabis use, daily cannabis use and cannabis dependence. Long-term trends in these patterns of cannabis consumption over two decades of observation were characterised to provide a broader context of usage. The effects of cannabis legalisation on patterns of cannabis consumption were quantified using logistic regression analyses. RESULTS: Long-term trends over the two decades of observation indicated that cannabis initiation decreased and then increased (p = 0.0220), any cannabis use decreased and daily cannabis use decreased (p < 0.0001 and p = 0.0001, respectively) and cannabis dependence remained unchanged (p = 0.1187). However, in comparisons between the pre-cannabis legalisation period (2001-2017) and the post-cannabis legalisation period (2019), cannabis legalisation was not associated with cannabis initiation (odds ratio; 95% confidence interval 1.00; 0.79-1.27), but it was associated with an increased likelihood of any cannabis use (1.31; 1.12-1.53), daily cannabis use (1.40; 1.09-1.80) and cannabis dependence (1.98; 1.29-3.04). DISCUSSION AND CONCLUSIONS: Cannabis legalisation was not associated with cannabis initiation, but it was associated with an increased likelihood of any cannabis use, daily cannabis use and cannabis dependence.

Cannabis legalization and cannabis use, daily cannabis use and cannabis-related problems among adults in Ontario, Canada (2001-2019).

BACKGROUND: In the context of cannabis legalization in Canada, we examined the effects on cannabis patterns of consumption, including cannabis use, daily cannabis use and cannabis-related problems. In addition, we examined differential effects of cannabis legalization by age and sex. METHODS: A pre-post design was operationalized by combining 19 iterations of the Centre for Addiction and Mental Health (CAMH) Monitor Surveys (N = 52,260; 2001-2019): repeated, population-based, cross-sectional surveys of adults in Ontario. Participants provided self-reports of cannabis use (past 12 months), daily cannabis use (past 12 months) and cannabis-related problems though telephone interviews. The effects of cannabis legalization on cannabis patterns of consumption were examined using logistic regression analyses, with testing of two-way interactions to determine differential effects by age and sex. RESULTS: Cannabis use prevalence increased from 11 % to 26 % (p < 0.0001), daily cannabis use prevalence increased from 1 % to 6 % (p < 0.0001) and cannabis-related problems prevalence increased from 6 % to 14 % (p < 0.0001) between 2001 and 2019. Cannabis legalization was associated with an increased likelihood of cannabis use (OR, 95 % CI: 1.62, 1.40-1.86), daily cannabis use (1.59, 1.21-2.07) and cannabis-related problems (1.53, 1.20-1.95). For cannabis-related problems, a significant two-way interaction was observed between cannabis legalization and age (p = 0.0001), suggesting differential effects among adults ≥55 years. CONCLUSIONS: Cannabis legalization was associated with an increased likelihood of cannabis use, daily cannabis use and cannabis-related problems. Given increases in these cannabis patterns of consumption, broader dissemination and uptake of targeted prevention tools is indicated.

The longitudinal relationship between cannabis use and hypertension.

INTRODUCTION: The relationship between cannabis use and hypertension is not clear based on prior epidemiological studies. Thus, we examined this relationship over a 3-year follow-up period using a large population-based sample from the USA. METHODS: Self-reported longitudinal data were obtained from the National Epidemiologic Survey on Alcohol and Related Conditions Wave 1 (2001/2002) and Wave 2 (2004/2005). The sample was restricted to participants who did not report hypertension at baseline (n = 26 844; 51% 40 years and older, 51% female, 71% white). χ2 -tests were used to examine the distributions of confounders stratified by the incidence of hypertension. Thereafter, multiple logistic regression analyses were conducted to quantify the relationships between lifetime cannabis use, 12-month cannabis use and 12-month cannabis use frequency and incidence of hypertension while adjusting for confounders. RESULTS: Cannabis use was associated with a decreased incidence of hypertension in the unadjusted analyses. However, the relationships were confounded by age. After adjustment for all confounders, neither lifetime cannabis use (odds ratio, 95% confidence interval 0.89, 0.77 to 1.02), 12-month cannabis use (0.78, 0.56 to 1.09) nor 12-month cannabis use frequency [at least monthly use (0.85, 0.57 to 1.28) and less than monthly use (0.67, 0.40 to 1.11)] were associated above chance with the incidence of hypertension. DISCUSSION AND CONCLUSIONS: Lifetime cannabis use, 12-month cannabis use and 12-month cannabis use frequency were not associated with the incidence of hypertension.

Brief Interventions for Cannabis Use in Healthcare Settings: Systematic Review and Meta-analyses of Randomized Trials.

OBJECTIVES: The efficacy of brief interventions for cannabis use was assessed in a systematic review and meta-analyses. METHODS: Systematic searches in academic databases were conducted, and reference lists of included studies were reviewed. Randomized trials were included that compared brief interventions with minimal control interventions for improving cannabis-specific outcomes among participants recruited from healthcare settings. Mean differences (MDs) based on change-from-baseline measurements were pooled using random-effects meta-analyses, with stratification by short term (≤3 months) and long term (>3 months). RESULTS: Ten reports from 9 studies were included. Most studies were conducted in the United States, including participants who were adults and were recruited from primary care or emergency departments. There were no significant effects of brief interventions on cannabis-specific Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) scores in the short term (MD -1.27 points; 95% confidence interval [CI] -3.75, 1.21; I 84.40%). The null pattern of findings was also observed for number of days of cannabis use in the past 30 days in the short term (MD -0.22 days; 95% CI -2.27, 1.82; I 60.30%) and long term (MD -0.28 days; 95% CI -2.42, 1.86; I 60.50%). The evidence base for other outcomes not subjected to meta-analyses was limited and mixed. CONCLUSIONS: Brief interventions did not result in reductions in cannabis-specific ASSIST scores or number of days of cannabis use, whereas the evidence base for other outcomes was limited and mixed. As such, brief interventions in healthcare settings may not be efficacious for cannabis use.

The relationship between cannabis use and diabetes: Results from the National Epidemiologic Survey on Alcohol and Related Conditions III.

INTRODUCTION AND AIMS: The relationship between cannabis use and diabetes is puzzling. Although cannabis users versus non-users should theoretically have a higher likelihood of diabetes, epidemiological studies suggest otherwise. However, previous epidemiological studies have not considered the potential confounding effects of mental health disorders. As such, the relationship between cannabis use and diabetes was examined while accounting for a range of potential confounders, including mental health disorders. DESIGN AND METHODS: Data were obtained from the National Epidemiologic Survey on Alcohol and Related Conditions III. Chi-square tests were used to compare socio-demographics, lifestyle behaviours, physical health disorders and mental health disorders between diabetics and non-diabetics. Measures that exhibited statistical significance in these tests were subsequently included in multiple logistic regression analyses to quantify the relationships between lifetime and 12-month cannabis use and diabetes. RESULTS: Although there was a considerable attenuation in the magnitude of the odds ratios after adjustment for confounders, there was still a decreased likelihood of diabetes for cannabis users versus non-users. The corresponding odds ratios of diabetes were 0.81 (95% confidence interval 0.70, 0.94) and 0.51 (95% confidence interval 0.41, 0.63) for lifetime and 12-month cannabis use, respectively. DISCUSSION AND CONCLUSIONS: A decreased likelihood of diabetes for cannabis users versus non-users was indicated after accounting for a range of potential confounders, including mental health disorders. Before the protective effects of cannabis use for diabetes can be suggested, further epidemiological studies are needed that incorporate prospective designs, as well as feature innovative exposure measurements and statistical analyses.

Substance use and population life expectancy in the USA: Interactions with health inequalities and implications for policy.

Life expectancy at birth for the USA has not increased in recent years. This commentary assesses the impact of substance use on this phenomenon. Although crude mortality rates of the most important causes of death (such as cardiovascular diseases or cancer) have declined between 2010 and 2014, crude mortality rates of drug- and alcohol-induced causes of death have increased. Alcohol use, non-medical prescription drug use (especially prescription opioid use) and illicit drug use have likely played a crucial role in life expectancy trends of the past years. Importantly, the current mortality crisis due to substances is disproportionately borne in lower socio-economic strata. As such, policies should reduce this impact.

The burden of disease attributable to cannabis use in Canada in 2012.

BACKGROUND AND AIMS: Cannabis use is associated with several adverse health effects. However, little is known about the cannabis-attributable burden of disease. This study quantified the age-, sex- and adverse health effect-specific cannabis-attributable (1) mortality, (2) years of life lost due to premature mortality (YLLs), (3) years of life lost due to disability (YLDs) and (4) disability-adjusted life years (DALYs) in Canada in 2012. DESIGN: Epidemiological modeling. SETTING: Canada. PARTICIPANTS: Canadians aged ≥ 15 years in 2012. MEASUREMENTS: Using comparative risk assessment methodology, cannabis-attributable fractions were computed using Canadian exposure data and risk relations from large studies or meta-analyses. Outcome data were obtained from Canadian databases and the World Health Organization. The 95% confidence intervals (CIs) were computed using Monte Carlo methodology. FINDINGS: Cannabis use was estimated to have caused 287 deaths (95% CI = 108, 609), 10,533 YLLs (95% CI = 4760, 20,833), 55,813 YLDs (95% CI = 38,175, 74,094) and 66,346 DALYs (95% CI = 47,785, 87,207), based on causal impacts on cannabis use disorders, schizophrenia, lung cancer and road traffic injuries. Cannabis-attributable burden of disease was highest among young people, and males accounted for twice the burden than females. Cannabis use disorders were the most important single cause of the cannabis-attributable burden of disease. CONCLUSIONS: The cannabis-attributable burden of disease in Canada in 2012 included 55,813 years of life lost due to disability, caused mainly by cannabis use disorders. Although the cannabis-attributable burden of disease was substantial, it was much lower compared with other commonly used legal and illegal substances. Moreover, the evidence base for cannabis-attributable harms was smaller.

Crude estimates of cannabis-attributable mortality and morbidity in Canada-implications for public health focused intervention priorities.

BACKGROUND: Cannabis is the most commonly used drug in Canada; while its use is currently controlled by criminal prohibition, debates about potential control reforms are intensifying. There is substantive evidence about cannabis-related risks to health in various key outcome domains; however, little is known about the actual extent of these harms specifically in Canada. METHODS: Based on epidemiological data (e.g. prevalence of relevant cannabis use rates and relevant risk behaviors; risk ratios; and annual numbers of morbidity/mortality cases in relevant domains), and applying the methodology of comparative risk assessment, we estimated attributable fractions for cannabis-related morbidity and mortality, specifically for: (i) motor-vehicle accidents (MVAs); (ii) use disorders; (iii) mental health (psychosis) and (iv) lung cancer. RESULTS: MVAs and lung cancer are the only domains where cannabis-attributable mortality is estimated to occur. While cannabis use results in morbidity in all domains, MVAs and use disorders by far outweigh the other domains in the number of cases; the popularly debated mental health consequences (e.g., psychosis) translate into relatively small case numbers. CONCLUSIONS: The present crude estimates should guide and help prioritize public health-oriented interventions for the cannabis-related health burden in the population in Canada; formal burden of disease calculations should be conducted.

Gender differences in health-related quality of life among cannabis users: results from the National Epidemiologic Survey on Alcohol and Related Conditions.

BACKGROUND: Cannabis is the most widely used illicit substance worldwide. The aim of the present study was to assess self-reported Quality of Life (QoL) among cannabis users in a large representative sample. METHODS: We analyzed data from the National Epidemiological Survey of Alcohol and Related Conditions (NESARC, n=43,093). Health-related QoL was assessed using the Short-form 12-item Health Survey (SF-12). The contribution of cannabis use and cannabis use disorders (CUD) to SF-12 scores was assessed using multiple linear regressions models. RESULTS: The prevalence of cannabis use and CUD in the last 12 months was 4.1% and 1.5%, respectively. Mean SF-12 mental summary scores were significantly lower (indicating a lower QoL) among female and male cannabis users compared to non-users (by 0.6 standard deviations (SD) and 0.3 SD, respectively), and among females and males with CUD compared to those without CUD (by 0.9 SD and 0.4 SD, respectively). Controlling for sociodemographic variables and mental illness, each joint smoked daily was associated with a greater decrease in mental QoL summary scores in females (0.1 SD) compared to males (0.03 SD). CONCLUSIONS: Cannabis use and CUD were associated with lower self-reported mental QoL. Specifically, our findings showed that cannabis use and CUD have a more significant effect on self-reported mental health QoL among female users. Assessing severity of cannabis use and impact of CUD should take into account functional and emotional outcomes. This may particularly aid in detecting the impact of cannabis use and CUD on mental health-related QoL among females.