Medical and recreational cannabis laws were associated with a 12-15% reduction in benzodiazepine fills but increases in antidepressant and antipsychotic prescriptions among commercially insured patients.
People interested in how cannabis legalization affects prescription drug use and mental health treatment.
12.4% reduction in benzodiazepine fills with medical cannabis laws
What the researchers found
Medical cannabis laws were associated with a 12.4% reduction in benzodiazepine fill rates, and recreational laws with a 15.2% reduction. Meanwhile, medical cannabis laws were associated with a 3.8% increase in antidepressant fills, and medical dispensary openings with an 8.8% increase.
Why it matters
The finding that cannabis laws may shift prescribing patterns away from benzodiazepines (which carry overdose risk) while increasing antidepressant use suggests cannabis policy may have complex, drug-class-specific effects on mental health treatment.
The numbers in context
3.85 million patients in the primary benzodiazepine sample. 12.4% reduction in benzo fill rate with medical cannabis laws. 15.2% reduction with recreational laws. 3.8% increase in antidepressant fills with medical laws. 8.8% increase with medical dispensary openings. 65.4% of the benzodiazepine sample were women.
How the study worked
Cross-sectional analysis of 10 million commercially insured patients from 2007-2020 using Optum claims data. A synthetic control method compared prescribing patterns across states with different cannabis policy timelines, examining medical/recreational laws and dispensary openings.
What this study cannot tell us
Cross-sectional design cannot establish causation. Commercially insured patients may not represent Medicaid or uninsured populations. The study cannot determine whether patients who reduced benzodiazepine use actually substituted cannabis. State-level heterogeneity was substantial.
How to read the evidence
Large dataset of 10 million patients with synthetic control methodology, though the cross-sectional design limits causal conclusions and state-level variation was considerable.
When this study was published
Published in 2024 in JAMA Network Open, covering data through 2020.
The bigger picture
This adds to growing evidence that cannabis legalization does not simply add substance use on top of existing medication patterns. Instead, it appears to reshape prescribing in ways that vary by drug class, potentially reflecting substitution effects or changes in how patients and clinicians approach mental health treatment.
Questions still open
- Are patients actively substituting cannabis for benzodiazepines, or are clinicians prescribing differently? Why did antidepressant prescriptions increase with cannabis laws? Do these prescribing shifts translate to better or worse patient outcomes?
Common questions
Did cannabis laws reduce all psychiatric medication use?
Does this mean people are replacing benzos with cannabis?
How large was this study?
Read the original research
Cannabis Laws and Utilization of Medications for the Treatment of Mental Health Disorders.
JAMA network open, 7(9), e2432021
Citation
Bradford, Ashley C; Lozano-Rojas, Felipe; Shone, Hailemichael Bekele; Bradford, W David; Abraham, Amanda J. (2024). Cannabis Laws and Utilization of Medications for the Treatment of Mental Health Disorders.. JAMA network open, 7(9), e2432021. https://doi.org/10.1001/jamanetworkopen.2024.32021