In a study published in the Journal of Health Economics, researchers examined the relationship between different marijuana legalization policies and opioid mortality rates in the U.S. Analyzing data from 1999 to 2019, researchers found that marijuana legalization is associated with higher opioid death rates, contradicting the marijuana protection hypothesis which proposes that the availability of marijuana reduces deaths from opioids.
In this study, researchers replicated and expanded upon prior research by accounting for incomplete reporting on the drugs involved in overdose deaths, better policy data, population weights, and included a greater time period for analysis. They observed that while opioid deaths did appear to reduce shortly after medical legalization policies took place, this reduction in deaths did not extend beyond 2013 and actually reversed directions with medical marijuana legalization and the sale of marijuana through retail dispensaries associated with greater opioid death rates. In one model, they found that medical marijuana laws were associated with an 18% rise in opioid death rates and policies allowing sales through medical marijuana dispensaries was associated with a 28% rise in opioid death rates.
In relation to policies allowing recreational marijuana and sales through recreational dispensaries, the findings were similar associating sales through recreational dispensaries with higher opioid death rates but these findings were not as strong. The authors noted that this is most likely attributed to a shorter time frame in which such policies were enacted and a limited number of states with such policies. They also analyzed the effects across population groups and found that recreational marijuana sales were associated with more opioid deaths for males compared to females, blacks and Hispanics compared to non-Hispanic whites, and for those aged 15-49 compared to older adults.
Access the research here. We encourage you to also check out the article, United States marijuana legalization and opioid mortality epidemic during 2010-2020 and pandemic implications.
Mathur, N. K., & Ruhm, C. J. (2023). Marijuana legalization and opioid deaths. Journal of Health Economics, 88. doi: 10.1016/j.jhealeco.2023.102728