Association for Public Policy Analysis & Management

Inappropriate prescribing of opioids for pain management is viewed as a major driver of the opioid epidemic in the U.S.. Marijuana can be effective in alleviating non-cancer pain. Therefore, marijuana may be a substitute for prescription opioids in pain management. The therapeutic potential of marijuana has been one of the most important policy rationales in many states that have legalized medical or adult use of marijuana. Empirical studies have found that medical marijuana laws (MMLs) and recreational marijuana laws (RMLs) are associated with reductions in daily opioid doses prescribed for Medicare Part D enrollees, opioid prescribing rates for Medicaid enrollees, opioid-related deaths, treatment rates related to opioid use disorders and overdose, and opioid-related fatal accidents.

We contribute to the literature by examining how marijuana liberalization policies, including MMLs and RMLs, affect opioid prescribing for those covered by private group health insurance. Previous studies only focus on opioid prescribing in Medicaid and Medicare population; and, no study has examined those with employer-sponsored health insurance.

We used difference-in differences models to identify the treatment effects of marijuana liberalization policies on opioid prescriptions.

We find that the implementation of MMLs and RMLs are associated with reductions in opioid prescriptions. Our findings suggest that marijuana may be a substitute for opioid prescriptions and marijuana liberalization policies may reduce opioid-related harms.