No Change in Cannabis Use Among High Risk Youth After Canada’s Legalization

This study looks at the cannabis profiles of high-risk youth before and after the legalization of recreational cannabis use in Canada.

Cannabis use among high-risk youth in Canada has remained consistent even after Canada legalized the drug in October 2018, according to a study published in the Journal of Substance Abuse Treatment.

Canada reports one of the highest rates of teenage cannabis use in the world. Because research has shown cannabis use can alter brain maturation in adolescents, the researchers wanted to examine the impact of legalization, particularly among “vulnerable” young people.

The study recruited participants who received treatment from the Youth Addictions and Concurrent Disorder Service in Toronto, Canada, between 2018 and 2020. They queried youth between April 2018 and October 2018 and between April 2019 and January 2020. The groups surveyed included 101 youth participants before legalization and 168 after legalization.

Most participants from both groups reported high-frequency cannabis use before legalization (N = 73, 75.3%), and after legalization (N = 130, 79.3%). There was no significant difference between the 2 time periods and between participants under and over age 19.

After legalization, more participants (35.7%) said they thought they had purchased cannabis from a government source compared to 10.9% pre-legalization. Young adults age 19 and over were more likely to report purchase from a government source. Most participants obtained cannabis from a dispensary, a friend, or a dealer.

Most participants used cannabis either alone or with friends. There was no significant difference in company before and after legalization.

Results may not translate to other settings. The cross-sectional cohort study does not examine changes among individuals over time. Data were self-reported. The study did not clearly define “dealer,” “dispensary,” and “government source.”

“Treatment programs should continue to develop and scale up integrated services that address cannabis use and polysubstance use challenges in conjunction with concurrent mental health challenges and other co-occurring psychosocial challenges,” the researchers concluded.


Hawke LD, Henderson J. Legalization of cannabis use in Canada: Impacts on the cannabis use profiles of youth seeking services for substance use. J Subst Abuse Treat. 2021.