Opioid-Related Deaths Reduced by Legalized Cannabis

A study examining the short-term effects of legalized cannabis in Colorado determined that the drug’s legalization has had an impact on the number of opioid-related deaths - by reducing them.

Led by Melvin Livingston (pictured), PhD, an assistant professor of biostatistics and epidemiology at the University of North Texas Health Science Center’s School of Public Health, the study found that cannabis legalization has reversed what had been an upward trend in opioid-related deaths in the state. The investigators did note that more data will be required in other states as time goes on, to see if the trend could be observed outside of Colorado.

Using data from the Centers for Disease Control and Prevention’s (CDC) wide-ranging online data for epidemiological research (WONDER) database, the study mapped out the number of opioid-related deaths from 2000 to 2013 and compared the mean to the mean through 2015. The data was equivalent to a decrease in 0.7 deaths per month (CI 95%, -1.34 to -0.03).

"These results are intriguing. We know that cannabis has an endorsement from the National Academy of Medicine, but recreational cannabis is not what we have data on," Mark Bicket, MD, the director of the Pain Medicine Fellowship training program at Johns Hopkins Medicine. "Prescription monitoring programs may also be having an effect that we’re not necessarily measuring. I think it’s something that’s going to have to be much more rigorously analyzed. We certainly need to have more studies on the topic and they need to take into account some of the other policies that are going on at the same time."

This is not the first study to relate opioids to cannabis use. A University of Michigan study from 2016 showed that cannabis users who suffered from chronic pain experienced a 64% drop in opioid use. Livingston and colleagues concluded that “Legalization of cannabis in Colorado was associated with short-term reductions in opioid-related deaths. As additional data become available, research should replicate these analyses in other states with legal recreational cannabis.”

“One thing that is an issue with debates like this is the assertion of causality when all you can assert is correlation,” David Nathan, MD, DFAPA, president of Doctors for Cannabis Regulation, told MD Magazine. “I don’t want to assert casualty, however, these correlations are consistent with the idea that the availability of cannabis cuts down on opioid-related overdoses. This is yet another suggestion that there may be benefits to legalization. Either this is an unintended consequence, or it’s a logical consequence of when you make a less lethal drug available in a world where the more dangerous drug is already legal.”

Nathan noted that current statistics point to a 25% decrease in prescription opioid-related overdoses that has been recorded in states with legalized medical cannabis, and suggested that it’s entirely possible that federalization of just medical cannabis could lead to a decrease in opioid-related death. But when it came to the possibility of reflecting Livingston’s findings on a national level, Nathan was optimistic.

“I think it could be higher nationally. If you listen to the opposition [to cannabis legalization], they’ll tell you that Colorado has had a high influx of drug users as a result of legalization,” he said. “If that is true, it would increase [the percentage of prevented opioid-related deaths] on a national level, since the number of drug users across a national level is a stable number.”

“We’re not seeing anything else that would indicate that Colorado had any advantage over any other state. The opposition would assert that Colorado has a problem, but this data seems to suggest the opposite,” he added.

The study was published in the American Journal of Public Health.