Study Finds Limited Impact of Cannabis Laws on Opioid Outcomes in the General Population
A study conducted by Columbia University Mailman School of Public Health has found that the adoption of medical and recreational marijuana laws has not significantly impacted opioid outcomes in the general population. However, the study revealed decreased opioid misuse and use disorder among individuals reporting cannabis use in states with medical marijuana laws (MCLs) but no changes associated with recreational marijuana laws (RCLs). The findings were published in the International Journal of Drug Policy.
Key Findings
The study analyzed data from the National Survey on Drug Use and Health (NSDUH) between 2015 and 2019, covering approximately 282,768 participants. Researchers assessed the relationship between cannabis law adoption and opioid outcomes, including prescription opioid misuse and heroin use.
- Medical Marijuana Laws (MCLs): The study observed a reduction in opioid misuse and use disorder among individuals reporting past-year cannabis use in states with MCLs.
- Recreational Marijuana Laws (RCLs): No significant changes in opioid outcomes were found when RCLs were adopted alongside MCLs.
The research highlights that the potential benefits of MCLs in reducing opioid misuse may not extend to states that implement both MCLs and RCLs.
Cannabis Use and Opioid Outcomes
From 2015 to 2019, the prevalence of opioid misuse was 4% for past-year use and 1.3% for past-month use among the general population. However, these rates were significantly higher—15% for past-year use—among individuals who reported cannabis use in the past year.
“Comparing individuals in states with MCLs alone to those without cannabis laws, we found decreased odds of opioid outcomes, particularly among people reporting cannabis use,” said Dr. Silvia Martins, Professor of Epidemiology at Columbia Mailman School. “This pattern was not observed in states with both RCLs and MCLs.”
Implications for Policy and Research
The findings suggest that MCLs may have modest benefits in reducing opioid misuse for cannabis users, but further research is needed to understand the effects of RCLs in combination with MCLs.
“States with MCLs alone showed some reductions in opioid-related harms, but these benefits were not apparent when both medical and recreational cannabis laws were in place,” noted Emilie Bruzelius, PhD, co-author and postdoctoral fellow at Columbia Mailman School.
Dr. Martins emphasized the need for ongoing studies:
“Our findings indicate that the impact of RCLs alongside MCLs may take more time to evaluate, as these laws are relatively recent. Monitoring opioid-related trends as more states adopt these laws is crucial.”
Research Context
The study is the first to explore the effects of cannabis laws on opioid outcomes among individuals who used cannabis before and after legalization in their states. It builds on prior research examining how cannabis legalization may influence opioid prescription rates, misuse, and overdose.
The research team included experts from Columbia Mailman School, NYU Grossman School of Medicine, Rutgers University, and the University of Arizona. The study was supported by grants from the National Institute on Drug Abuse (NIDA).
Conclusion
While medical cannabis laws show promise in mitigating opioid misuse among cannabis users, the broader impact of recreational cannabis legalization remains unclear. Future research will need to address these gaps to inform policymakers and healthcare providers.
Source: Eurek Alert