Among Medicare patients with chronic noncancer pain in 7 states, medical cannabis laws had no measurable effect on cannabis or opioid use disorder treatment or overdose-related healthcare use.
Health policy researchers and policymakers evaluating medical cannabis as an opioid crisis strategy.
Less than 0.005 percentage point effect on opioid treatment
What the researchers found
Medical cannabis laws had estimated effects of less than 0.005 percentage points on CUD or OUD treatment, less than 0.009 points on new treatment initiation, and less than 0.0005 points on overdose-related care (all p > 0.05). The findings do not support the hypothesis that medical cannabis laws reduce opioid-related harms among chronic pain patients.
Why it matters
Medical cannabis laws are often justified partly by the potential to reduce opioid harms for pain patients. This rigorous analysis finds no evidence of this effect among Medicare beneficiaries, adding to the mixed evidence on cannabis-opioid substitution.
The numbers in context
7 treatment states (FL, MD, MN, NH, NY, OK, PA) vs 17 comparison states. CUD/OUD treatment effect: < 0.005 percentage points. New treatment initiation: < 0.009 pp. Overdose care: < 0.0005 pp. All p > 0.05.
How the study worked
Difference-in-differences and augmented synthetic control analyses comparing Medicare beneficiaries with chronic noncancer pain in 7 states implementing medical cannabis laws versus 17 comparison states without such laws. Examined CUD and OUD treatment and overdose-related healthcare utilization.
What this study cannot tell us
Medicare population tends to be older and may not represent all chronic pain patients. Claims data cannot determine whether patients actually used medical cannabis. State-level policy implementation varies. The study examines treatment-seeking, not opioid use itself.
How to read the evidence
Difference-in-differences and synthetic control analyses of Medicare claims. Strong quasi-experimental design comparing 7 treatment and 17 comparison states.
When this study was published
Published in 2025 in The Milbank Quarterly.
The bigger picture
This adds to growing evidence that the population-level effects of medical cannabis laws on opioid outcomes are minimal. While individual patients may benefit from cannabis-opioid substitution, the effect does not appear at a scale detectable in Medicare claims data.
Questions still open
- Do medical cannabis laws affect opioid outcomes in younger or privately insured populations? Would cannabis-specific treatment programs within pain clinics produce different results?
Common questions
Does medical cannabis help with the opioid crisis?
Why focus on Medicare patients?
Read the original research
The Impact of Medical Cannabis Laws on Cannabis and Opioid Use Disorder Treatment and Overdose-Related Health Care Utilization Among Adults With Chronic Noncancer Pain.
The Milbank quarterly, 103(S1), 411-434
Citation
McGinty, Emma E; Wagle, Pradhyumna; Luo, Christie Lee; Seewald, Nicholas J; Stuart, Elizabeth A; Tormohlen, Kayla N. (2025). The Impact of Medical Cannabis Laws on Cannabis and Opioid Use Disorder Treatment and Overdose-Related Health Care Utilization Among Adults With Chronic Noncancer Pain.. The Milbank quarterly, 103(S1), 411-434. https://doi.org/10.1111/1468-0009.70052