(Kiosk 7) Association Between Opioid-related Mortality Rates and Recreational Cannabis Legalization in Four US States

Background and/or Objectives: To examine the potential relationship between opioid-related mortality rates and the legalization of cannabis for recreational use.

Design: Retrospective analysis

Setting: Two US states with total bans on cannabis and two US states with longstanding recreational cannabis legalization.

Participants: US mortality data from the Centers for Disease Control and Prevention was used in combination with US census data to calculate opioid-related death rates by population.

Interventions: Not applicable

Main Outcome Measures: Mortality rates associated with all opioid types in four U.S. states and the change in rates over time from 1999-2021. Average death rates by population were compared pre- and post-implementation of recreational cannabis legalization using a two-tailed, two-sample equal variance t-test.

Results: Opioid-related death rates by population have increased across all four states from 1999-2021. Opioid-related death rates in Colorado and Oregon, which implemented the legalization of recreational cannabis in 2014 and 2015, respectively, have remained steady over time when compared with North Carolina and South Carolina, which saw steady increases since 2013. Death rates were not significantly different in the years prior to the implementation of recreational cannabis legalization but showed a significant difference post-implementation between cannabis banned vs legalized states.

Conclusions: There is a potential association between legalized recreational cannabis and reduced opioid-related deaths. The significant difference in opioid-related deaths after the implementation of legalized cannabis laws suggests opioid use and misuse may be related to the availability of other drug products.