Canadian Centre on Substance Use and Addiction

Nguyen, H., Mital, S., Grootendorst, P., & Bornstein, S.

This study had three objectives: (i) investigate the impact of recreational cannabis legislation on cannabis use among Canadian youth; (ii) examine if a higher minimum legal age in Quebec reduced youth cannabis use; and, (iii) quantify the effect of recreational cannabis legislation on medical cannabis use. The study used data from several secondary data sources including various national surveys between 2004 and 2019 (e.g., National Cannabis Survey, the Canadian Tobacco Use Monitoring Survey) and data on medical cannabis shipments from Health Canada.

The first objective found that legalization had no impact on the overall prevalence of youth cannabis use, but there was a 69% increase in cannabis initiation among those aged 15-18. The second objective found that an increase in the minimum legal age in Quebec from 18 to 21 led to a 51% reduction in cannabis use among those aged 18-20, but there was no change in use among those aged 15-17. The third objective found that recreational cannabis legalization led to a significant decrease in medical cannabis use (6-48%) across seven provinces, with an overall decline of 18%. It is possible that some medical cannabis users may have switched to the illegal or recreational markets after legalization.


Nguyen, H. V., Grootendorst, P., Mital, S., Bishop, L., & McGinty, E. E. (2023). Changes in medical cannabis use after recreational cannabis legalization in Canada. Cannabis and Cannabinoid Research. Advance online publication.

Nguyen, H. V., & Mital, S. (2022). Changes in youth cannabis use after an increase in cannabis minimum legal age in Quebec, Canada. JAMA Network Open, 5(6), e2217648.

Nguyen, H. V., Mital, S., & Bornstein, S. (2023). Short-term effects of recreational cannabis legalization on youth cannabis initiation. The Journal of Adolescent Health, 72(1), 111-117.

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