What Happens When Countries Regulate Cannabis: Arrests Drop, Adult Use Rises
A systematic review across five jurisdictions found that regulated cannabis supply consistently decreased cannabis arrests and increased adult use, while negative health outcomes were most pronounced in US states.
Quick Facts
What This Study Found
Across the Netherlands, Spain, US legalization states, Uruguay, and Canada, consistent outcomes included decreased cannabis-related arrests, increased adult (but not adolescent) cannabis use, and increased healthcare utilization (not traffic-related). Negative health outcomes were most concentrated in US states. Evidence was limited for non-US jurisdictions.
Key Numbers
Five jurisdictions compared. Consistent outcomes: decreased arrests, increased adult use (not adolescent), increased non-traffic healthcare utilization. US states showed most negative health outcomes. Other jurisdictions had limited study designs or timeframes.
How They Did This
Three-level systematic literature review assessing nine indicators across three domains (social, cannabis use, health-related) in five jurisdictions with different regulation models. Prioritized quasi-experimental studies and categorized by study design and outcome direction.
Why This Research Matters
With more countries considering cannabis regulation, comparing outcomes across different models helps identify which approaches minimize harms while achieving social benefits like reduced criminalization.
The Bigger Picture
No single regulation model achieves all desired outcomes. The variation in results across jurisdictions suggests that the specific design of cannabis regulation matters significantly for public health outcomes.
What This Study Doesn't Tell Us
Heterogeneity in regulation models makes direct comparison difficult. US states dominate the evidence base. Non-US jurisdictions had fewer rigorous studies and shorter follow-up periods. Could not fully distinguish between regulation model effects and other country-specific factors.
Questions This Raises
- ?Which specific regulatory features drive the different outcomes?
- ?Can countries design hybrid models that capture benefits while minimizing harms?
- ?Why do US states show more negative health outcomes?
Trust & Context
- Key Stat:
- Adult use increased across all jurisdictions; adolescent use did not
- Evidence Grade:
- Strong: systematic review across multiple jurisdictions prioritizing quasi-experimental evidence, though limited by heterogeneity in regulation models and evidence quality
- Study Age:
- Published in 2025
- Original Title:
- Getting "The whole picture": A review of international research on the outcomes of regulated cannabis supply.
- Published In:
- The International journal on drug policy, 142, 104796 (2025)
- Authors:
- Belackova, Vendula(2), Petruzelka, Benjamin, Cihak, Jakub, Michailidu, Jana, Mravcik, Viktor
- Database ID:
- RTHC-06037
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Does cannabis legalization increase teen use?
Across all five jurisdictions reviewed (Netherlands, Spain, US, Uruguay, Canada), regulated cannabis supply was associated with increased adult use but not adolescent use. This is one of the more consistent findings across different regulation models.
Which regulation model works best?
No single model emerged as clearly superior. The review found that different models have different trade-offs. The authors suggest jurisdictions may need to mix elements from different approaches to achieve the best balance of benefits and harms.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-06037APA
Belackova, Vendula; Petruzelka, Benjamin; Cihak, Jakub; Michailidu, Jana; Mravcik, Viktor. (2025). Getting "The whole picture": A review of international research on the outcomes of regulated cannabis supply.. The International journal on drug policy, 142, 104796. https://doi.org/10.1016/j.drugpo.2025.104796
MLA
Belackova, Vendula, et al. "Getting "The whole picture": A review of international research on the outcomes of regulated cannabis supply.." The International journal on drug policy, 2025. https://doi.org/10.1016/j.drugpo.2025.104796
RethinkTHC
RethinkTHC Research Database. "Getting "The whole picture": A review of international resea..." RTHC-06037. Retrieved from https://rethinkthc.com/research/belackova-2025-getting-the-whole-picture
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.