Cannabis Decriminalization and Legalization Both Reduced Arrests, but Racial Disparities Persisted
A systematic review of 17 studies found cannabis decriminalization and legalization consistently reduced arrests by 13-87%, but racial and ethnic disparities in enforcement persisted or even increased in some cases.
Quick Facts
What This Study Found
100% of studies (7/7) showed significant reductions after decriminalization (13.5-78% reduction). 75% of studies (6/8) showed reductions after legalization (33-87%). Legalization consistently reduced adult offences but not always youth offences. Despite absolute reductions across racial groups, relative disparities were variable, increasing in some jurisdictions while decreasing in others.
Key Numbers
17 studies from 2,806 screened. Decriminalization: 13.5-78% reduction in offences (7/7 studies). Legalization: 33-87% reduction (6/8 studies). In previously decriminalized states, legalization added 35-84% further reduction (2/3 studies). Youth reductions less consistent than adult.
How They Did This
Systematic review of 7 databases yielding 17 studies from North America (15 USA, 2 Canada). Examined changes in cannabis arrests, charges, convictions, and referrals after four policy types: medical legalization, decriminalization, non-medical legalization, and commercialization. Synthesis without meta-analysis.
Why This Research Matters
Reducing criminal justice harms is a primary justification for cannabis legalization. This review confirms that both decriminalization and legalization achieve this goal but reveals that they do not automatically eliminate racial disparities in enforcement, which was another stated goal.
The Bigger Picture
The persistence of racial disparities despite absolute reductions in cannabis offences suggests that enforcement patterns reflect deeper systemic issues beyond cannabis policy. Additional interventions beyond legalization are needed to achieve equity in criminal justice outcomes.
What This Study Doesn't Tell Us
All 17 studies were from North America. Limited evidence on commercialization effects (only 2 studies). Youth-specific data was sparse. The review could not account for differences in implementation and enforcement across jurisdictions.
Questions This Raises
- ?What additional policies beyond legalization are needed to eliminate racial enforcement disparities?
- ?Why does legalization reduce adult but not always youth cannabis offences?
Trust & Context
- Key Stat:
- 13-87% reduction in cannabis offences, but racial disparities persist
- Evidence Grade:
- Systematic review of 17 studies with consistent findings on offence reduction. Strong evidence for overall effects; mixed evidence on disparity impacts.
- Study Age:
- Published in 2025.
- Original Title:
- Evaluating the association between cannabis decriminalization and legalization and cannabis arrests and related disparities: A Systematic review.
- Published In:
- The International journal on drug policy, 137, 104705 (2025)
- Authors:
- McCarthy, Stephen D S, Gaudreault, Adrienne(4), Xiao, Jennifer(4), Fischer, Benedikt, Hall, Wayne, Lee, Kathryn, Kang, Rachel, Aslanyan, Garry, Sood, Manish M, Myran, Daniel T
- Database ID:
- RTHC-07093
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Does legalization eliminate cannabis arrests?
Not entirely, but it substantially reduces them (33-87% in most studies). Some cannabis-related offences remain, such as underage possession, driving under the influence, and unlicensed sale.
Why do racial disparities persist after legalization?
Cannabis enforcement occurs within broader policing patterns. Legalization may reduce the absolute number of arrests across all groups while not changing the relative likelihood of enforcement in different communities.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-07093APA
McCarthy, Stephen D S; Gaudreault, Adrienne; Xiao, Jennifer; Fischer, Benedikt; Hall, Wayne; Lee, Kathryn; Kang, Rachel; Aslanyan, Garry; Sood, Manish M; Myran, Daniel T. (2025). Evaluating the association between cannabis decriminalization and legalization and cannabis arrests and related disparities: A Systematic review.. The International journal on drug policy, 137, 104705. https://doi.org/10.1016/j.drugpo.2025.104705
MLA
McCarthy, Stephen D S, et al. "Evaluating the association between cannabis decriminalization and legalization and cannabis arrests and related disparities: A Systematic review.." The International journal on drug policy, 2025. https://doi.org/10.1016/j.drugpo.2025.104705
RethinkTHC
RethinkTHC Research Database. "Evaluating the association between cannabis decriminalizatio..." RTHC-07093. Retrieved from https://rethinkthc.com/research/mccarthy-2025-evaluating-the-association-between
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.