By Roger Chriss, PNN Columnist
A new study published in The BMJ claims that U.S. counties with medical and recreational cannabis dispensaries have fewer opioid-related deaths.
Researchers at Yale and University of California at Davis found that an increase of just one or two storefront dispensaries in a county was associated with a 17% reduction in all-opioid mortality rates. Deaths involving illicit fentanyl and other synthetic opioids fell by 21 percent.
Although the researchers cautioned that “the associations documented cannot be assumed to be causal,” cannabis supporters were quick to praise the findings.
“The data to date is consistent and persuasive: For many pain patients, cannabis offers a viable alternative to opioids, potentially improving their quality of life while possessing a superior safety profile,” said Paul Armentano, Deputy Director of NORML, a marijuana advocacy group.
While the study findings are interesting, they highlight the importance of considering the complex supply side of legal and illegal drug markets, and how it shapes opioid use and misuse. The study looked at data from over 800 counties with legal dispensaries, and compared them to counts of fatal overdoses between 2015 and 2018.
It turns out many of these counties were on the West Coast, where illicit fentanyl had yet to became as pervasive on the black market as it had in other parts of the country. Since 2018, deaths involving fentanyl have soared on the West Coast.
“If you were to do the same study with current data, you’d find something different because of the way both opioid deaths and cannabis dispensaries have shifted since then,” Chelsea Shover, PhD, an assistant professor at UCLA School of Medicine told Healthline.
In general, the opioid overdose crisis has gotten worse in the past couple of years. The CDC recently reported that in the 12 months ending in May 2020, ten western states reported a nearly 100 percent increase in deaths involving illicit fentanyl and other synthetic opioids. The increase was particularly sharp in states that legalized recreational cannabis.
This is the problem with ecological data and associational findings. If you pick the right time or place, you can get an appealing result. And you may ignore other important issues.
States that legalized cannabis tend to have better public health and more addiction treatment services. They generally have adopted the Affordable Care Act and Medicaid expansion, and have stronger social safety nets. All of these factors are believed to contribute to rates of substance use disorders and overdose risk.
Ecological data alone never proves anything. It merely suggests associations. If the association holds up over time, then researchers can look into a possible causal relation. If however, the association does not hold up, then claims about causality are pointless.
At this point cannabis does not seem to reliably reduce opioid overdose deaths. Further research will be needed to tease out the effects of cannabis legalization amid all the other factors involved in the overdose crisis.
Roger Chriss lives with Ehlers Danlos syndrome and is a proud member of the Ehlers-Danlos Society. Roger is a technical consultant in Washington state, where he specializes in mathematics and research.