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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.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.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.

Considering the widespread use of cannabis and opioids, examining the use of cannabis, opioids and their combination with serious psychological distress (SPD) is important. A total of N = 12,358 adults participating in the Monitor surveillance study between 2014 and 2019 were included. Cannabis and opioid use reflected any use of the substances in the past 12 months. SPD was defined as having a score of 13 or more on the Kessler-6 questionnaire, a 6-item scale that includes feeling nervous, hopeless, restless or fidgety, sad or depressed. Odds ratios (ORs) were estimated from logistic regression models accounting for complex survey design and sociodemographic factors. Overall, 12.8% of the sample reported cannabis use only, 18% reported opioid use only, and 4.9% reported both cannabis and opioid use. Use of both cannabis and opioids was significantly associated with SPD in both women (OR = 4.24; 95% CI, 2.34 to 7.69), and in men (OR = 2.99; 95% CI, 1.56 to 5.73) compared to use of neither. The joint association of cannabis and opioids with SPD was additive. Addressing those who use both cannabis and opioids may help reduce the burden of SPD among adults in Ontario.

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.