New studies link legal marijuana with fewer opioid prescriptions

NEW YORK Can legalizing marijuana fight the problem of opioid addiction and fatal overdoses? Two new studies in the debate suggest it may.

Pot can relieve chronic pain in adults, so advocates for liberalizing marijuana laws have proposed it as a lower-risk alternative to opioids. But some research suggests marijuana may encourage opioid use, and so might make the epidemic worse.

The new studies don’t directly assess the effect of legalizing marijuana on opioid addiction and overdose deaths. Instead, they find evidence that legalization may reduce the prescribing of opioids. Over-prescribing is considered a key factor in the opioid epidemic.

Both studies were released Monday by the journal JAMA Internal Medicine.

One looked at trends in opioid prescribing under Medicaid, which covers lowincome adults, between 2011 and 2016. It compared the states where marijuana laws took effect versus states without such laws. The comparison was done each quarter, so a given state without a law at one point could join the other category once a law kicked in.

Results showed that laws that let people use marijuana to treat specific medical conditions were associated with about a 6 per cent lower rate of opioid prescribing for pain. That’s about 39 fewer prescriptions per 1,000 people using Medicaid.

And when states with such a law went on to also allow recreational marijuana use by adults, there was an additional drop averaging about 6 per cent. That suggest the medical marijuana laws didn’t reach some people who could benefit from using marijuana instead of opioids, said Hefei Wen of the University of Kentucky in Lexington, one of the study authors.