Enactment of Adult-Use Marijuana Legalization Associated with Immediate, But Temporary Reductions in Opioid-Related Emergency Room Visits

Boston, MA: The enactment of adult-use marijuana legalization laws is associated with immediate reductions in opioid-related emergency department (ED) visitation rates among men, according to data published in the journal Health Economics.

A team of investigators from the Harvard Pilgrim Health Care Institute and the University of Pittsburgh assessed the relationship between marijuana legalization and opioid-related ED visitation rates in 29 states over a six-year period (2011-2017). Four of those states enacted adult-use access during the study period, and researchers compared trends in these legal states with trends in the remaining 25 states.

Authors reported that ED visit rates fell nearly eight percent among males (ages 24 to 44) during the first six-months following the enactment of legalization laws. However, these reductions dissipated in the months that followed and were no longer significant within one year.

“Our results indicate that RCLs [recreational marijuana laws] may only affect a temporary reduction in opioid-related ED visits,” they concluded. “While cannabis liberalization may offer some help in curbing the opioid crisis, our results suggest that it is not a panacea.”

The study’s lead investigators added: “We can’t definitively conclude from the data why these laws are associated with a temporary downturn in opioid-related emergency department visits but, based on our findings and previous literature, we suspect that people who use opioids for pain relief are substituting with cannabis, at least temporarily. … [T]his is good news for state policymakers. States can fight the opioid epidemic by expanding access to opioid use disorder treatment and by decreasing opioid use with recreational cannabis laws. These policies aren’t mutually exclusive; rather, they’re both a step in the right direction.”

Full text of the study, “Recreational cannabis laws and opioid-related emergency department visit rates,” appears in Health Economics. Additional information is available from the NORML fact sheet, ”Relationship Between Marijuana and Opioids.