Canada's Legal Age for Cannabis May Be Protecting Youth From Hospitalizations
After cannabis legalization in Canada, cannabis-related hospitalizations dropped 34% among youth below the minimum legal age while continuing to rise among adults above it.
Quick Facts
What This Study Found
Cannabis-related hospitalizations declined by 2% per quarter among individuals below the minimum legal age after legalization, while no slope change occurred for those above the MLA. By 3.5 years post-legalization, hospitalizations were 34% lower for those below the MLA relative to those above it.
Key Numbers
14.6 million individuals in 2018; 137,901 cannabis-related hospitalizations during study period; 34% relative reduction below MLA at 3.5 years post-legalization (RR 0.66, 95% CI 0.49-0.91); pre-legalization rates were increasing 2% per quarter for both groups.
How They Did This
Population-based controlled interrupted time series study examining all cannabis-related hospitalizations in Canada for individuals aged 15-44 (n=14.6 million in 2018) from January 2015 to March 2022, comparing trends above and below varying provincial MLAs.
Why This Research Matters
This is one of the first large-scale studies to show that minimum legal age laws for cannabis may actually work as intended, reducing harm among youth while the same harms increase among the adult population with legal access.
The Bigger Picture
This study provides evidence that cannabis age restrictions can be effective public health tools, similar to alcohol and tobacco age laws. The finding that adult hospitalizations continued rising post-legalization adds nuance to the legalization debate.
What This Study Doesn't Tell Us
Observational design cannot prove causation. Cannot distinguish whether reduced youth hospitalizations reflect less use, safer use, or shifts in healthcare-seeking behavior. Provincial MLA variations could introduce confounding. Hospitalization data may undercount less severe cannabis-related harms.
Questions This Raises
- ?What is driving the continued increase in adult hospitalizations?
- ?Are the youth reductions sustained beyond 3.5 years?
- ?Would a higher MLA (such as 25) produce even greater reductions?
Trust & Context
- Key Stat:
- 34% fewer cannabis hospitalizations among youth below the legal age, 3.5 years after legalization
- Evidence Grade:
- Strong: Large population-based study (14.6 million) with a rigorous controlled interrupted time series design that leverages natural policy variation across Canadian provinces.
- Study Age:
- Published in 2025 with data through March 2022.
- Original Title:
- Minimum Legal Age of Nonmedical Cannabis Purchase Laws and Cannabis-Related Hospitalizations in Canada, 2015 to 2022.
- Published In:
- American journal of public health, 115(7), 1166-1174 (2025)
- Authors:
- Myran, Daniel T(16), Talarico, Robert, Pacula, Rosalie Liccardo(18), Xiao, Jennifer, Manuel, Doug, Hobin, Erin, Konikoff, Lauren, Tanuseputro, Peter, Taljaard, Monica
- Database ID:
- RTHC-07216
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Why did youth hospitalizations go down while adult hospitalizations went up?
The minimum legal age created a regulatory barrier for youth that did not exist before legalization. Meanwhile, adults gained easier legal access to cannabis, which may have increased use and associated harms in that group.
Does this mean legalization is good for youth?
The study suggests that age restrictions within a legalization framework can reduce cannabis-related hospitalizations among youth. However, it does not address all potential harms, and the continued rise among adults shows legalization has trade-offs.
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Cite This Study
https://rethinkthc.com/research/RTHC-07216APA
Myran, Daniel T; Talarico, Robert; Pacula, Rosalie Liccardo; Xiao, Jennifer; Manuel, Doug; Hobin, Erin; Konikoff, Lauren; Tanuseputro, Peter; Taljaard, Monica. (2025). Minimum Legal Age of Nonmedical Cannabis Purchase Laws and Cannabis-Related Hospitalizations in Canada, 2015 to 2022.. American journal of public health, 115(7), 1166-1174. https://doi.org/10.2105/AJPH.2025.308090
MLA
Myran, Daniel T, et al. "Minimum Legal Age of Nonmedical Cannabis Purchase Laws and Cannabis-Related Hospitalizations in Canada, 2015 to 2022.." American journal of public health, 2025. https://doi.org/10.2105/AJPH.2025.308090
RethinkTHC
RethinkTHC Research Database. "Minimum Legal Age of Nonmedical Cannabis Purchase Laws and C..." RTHC-07216. Retrieved from https://rethinkthc.com/research/myran-2025-minimum-legal-age-of
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.