Prevalence and modes of cannabis use among youth in Canada, England, and the US, 2017 to 2019

Objective: Cannabis markets are evolving in terms of greater diversity and potency of products. The current study examined changes in cannabis use and modes of consumption among 16- to 19-year-olds in three markets with different regulatory frameworks: England, Canada, and the United States (US). Methods: Repeat cross-sectional online surveys were conducted in 2017, 2018, and 2019, with samples of 16- to 19-year-olds recruited from commercial panels in Canada (n = 11,779), England (n = 11,117), and the US (n = 11,869). Regression models examined changes in the prevalence of any cannabis use and use of seven modes of consumption, across the countries. Results: Cannabis use among youth was more prevalent among respondents in Canada and the US than in England in all years and increased to a greater extent between 2017 and 2019 (p < .001 for all contrasts). Among past 30-day cannabis consumers, the prevalence of vaping oils/liquids and the use of cannabis extracts (oil, wax and shatter) increased in all countries, and was significantly higher in Canada and US. For example, the prevalence of vaping oils/liquids increased from 24.2 % in 2017 to 52.1 % in 2019 among past 30-day cannabis consumers in the US (AOR = 3.46, 95 %CI = 2.57-4.66). Conclusion: Prevalence is increasing for the most potent categories of cannabis products, particularly among youth in Canada and the US. Future research should examine the potential risks of these products and whether shifts in modes of cannabis reflect recent permissive changes to cannabis policy.