By Sami Aftab Abdul , Huan Jiang , .Cayley Russell , Tara Elton-Marshall , et al.
Background
British Columbia, Canada implemented a three-year pilot program on January 31, 2023 decriminalizing personal possession of select illegal drugs. The policy aimed to increase access to health and social services. This analysis evaluated the short-term impacts of decriminalization on clients dispensed opioid agonist treatment (OAT) medications and visits to supervised consumption and overdose prevention services (SCS/OPS).
Methods
Population-based data from 2015 to 2023 were sourced (Pre-decriminalization: Jan 2015–Jan 2023; Post-decriminalization Feb 2023–Dec 2023). Generalized additive models in an interrupted time series design were used to model monthly total and sex-stratified, age-standardized rates of clients and first-time clients dispensed OAT medications per 100,000 population, as well as crude rates of visits to SCS/OPS per 100,000 population. The models tested both immediate level changes (immediate effect at decriminalization) and trend changes (slope changes post-decriminalization).
Results
The models detected no association between decriminalization and changes in clients dispensed OAT medications (Immediate Change β [95 % CI]: −0.001 [−0.012, 0.011]; Trend Change β [95 % CI]: −0.004 [−0.011, 0.003]), first-time clients dispensed OAT medications (Immediate Change β [95 % CI]: 0.115 [−0.049, 0.279]; Trend Change β [95 % CI]: −0.006 [−0.048, 0.035]) or visits to SCS/OPS (Immediate Change β [95 % CI]: 0.048 [−0.100, 0.195]; Trend Change β [95 % CI]: 0.013 [−0.016, 0.043]). Findings for all outcomes remained consistent after stratifying by sex.
Conclusion
Decriminalization was not associated with changes in clients dispensed OAT medications, first-time clients dispensed OAT medications, or visits to SCS/OPS. These findings reflect only the initial eleven months following the implementation of the policy. Given the complexity of factors influencing service utilization, and the introduction of the second amendment which represents a significant rollback of the original exemption, longer-term evaluations are needed to more accurately assess whether decriminalization is contributing to its intended goals.
Journal of Substance Use and Addiction Treatment
Volume 180, January 2026, 209815