Study Links Reduction in Opioid Deaths to Increase in Cannabis Dispensaries at County Level

Increased numbers of storefront cannabis dispensaries-whether medical or recreational-are associated with reduced opioid related death rates, particularly deaths associated with synthetic opioids such as fentanyl, according to an analysis of data from 812 counties in 23 states (and the District of Columbia) with legal cannabis dispensaries.1

An accompanying editorial by a policy expert cautions making inferences about cannabis use at an individual level, however.

"While the associations documented cannot be assumed to be causal, they suggest a potential association between increased prevalence of medical and recreational cannabis dispensaries and reduced opioid-related mortality rates," wrote the authors, Greta Hsu, PhD, of University of California Davis Graduate School of Management, and Balazs Kovacs, PhD, of Yale University School of Management.

Hsu and Kovacs wrote, "This study highlights the importance of considering the complex supply side of related drug markets and how this shapes opioid use and misuse."1

They found that county-level dispensary count (natural logarithm) is negatively related to the log transformed, age-adjusted mortality rate associated with all opioid types ([beta] = -0.17, 95% confidence interval -0.23 to -0.11).

According to this estimate, an increase from 1 storefront dispensary in a county to 2 dispensaries is associated with an estimated 17% reduction in all opioid related mortality rates.

"Dispensary count has a particularly strong negative association with deaths caused by synthetic opioids other than methadone ([beta] = -0.21, 95% confidence interval -0.27 to -0.14), with an estimated 21% reduction in mortality rates associated with an increase from 1 to 2 dispensaries. Similar associations were found for medical versus recreational storefront dispensary counts on synthetic (non-methadone) opioid related mortality rates,"1 the authors wrote.

In the accompanying editorial,2 Sameer Imtiaz, PhD, of the Institute for Mental Health Policy Research in Toronto, and co-authors wrote that it is too soon to tell whether cannabis "liberalization" reduces opioid deaths, and that inferences cannot be drawn about individual use from the data collected by Hsu and Kovacs.

"In the context of medicinal cannabis legalization, reduced deaths from opioid overdose do not coincide with reduced non-medicinal use of pain relievers or with opioid distribution, defined as the flow of substances from the manufacturers to retail distributors," they wrote. "The absence of concurrent changes in such opioid-related outcomes questions the premise of substitution."2

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