Could medical marijuana alleviate the state’s drug epidemic?

A medical marijuana user displayed bought from a dispensary in Salem in June.Jonathan Wiggs/Globe staff

Consider this counterintuitive fact: One reason overdose deaths in Massachusetts have shot up 50 percent in the past few years is that the crackdown on prescription opioids has worked extremely well.

It has become a lot harder for users to get those drugs but that doesn't mean they all sought treatment or were suddenly freed of their addiction. Rather, the evidence suggests that many turned to heroin, which is even deadlier.

Here's one approach that's rarely discussed but seems to curb abuse of prescription opioids — without the risk of driving users to heroin: Increase access to medical marijuana.

Are we fighting a prescription opioid crisis or a heroin crisis?

We seem to be at a transition point. Prescription opioids became a scourge in the 2000s, when pill mills made it easier to get the drugs, and overdose deaths in the United States shot up from about 4,000 per year to more than 16,000, according to the Centers for Disease Control and Prevention.

But those harrowing death rates stopped growing around 2010, thanks in large part to effective new regulations that made prescription opioids harder to get, and harder to abuse.

Yet, that wasn't the end of the opioid crisis. It was just the beginning of a new phase, centered around heroin.

A 2012 study in the New England Journal of Medicine found that the crackdown on prescription drugs really did drive some users toward heroin. It's not a huge number of users: The Drug Enforcement Administration estimates that only about 3.6 percent of prescription opioid addicts make the switch to heroin. But given that heroin is more potent, and deadlier, even a relatively small influx of users can have devastating consequences.

Since 2010, heroin deaths in the United States have more than doubled.

It's hard to say for sure whether the trend is identical here in Massachusetts, since state data don't distinguish between deaths from heroin and deaths from other opioids. But if Massachusetts looks anything like the rest of the nation, heroin is what's fueling the recent surge in overdose deaths.

Is there a way to end this crisis?

Prescription opioids have a legitimate, and vital, medical purpose: They help people manage pain. Unfortunately, they are also quite addictive and seem to put some users on a path toward heroin.

The ideal solution would be to find a better, less addictive, and less dangerous way to treat pain. And one drug that might fit the bill is medical marijuana.

Not only has marijuana been shown to treat chronic pain, but a recent study from researchers at the RAND Corporation and University of California Irvine found that increased access to medical marijuana curtailed prescription opioid abuse and overdose deaths.

You might object that this amounts to swapping one drug for another, but marijuana is a very different kind of drug. First, marijuana overdose deaths are vanishingly rare — virtually non-existent. For another, marijuana isn't a gateway drug for heroin; Because it's not an opioid, it doesn't create the kind of addiction that heroin could soothe.

This hardly makes medical marijuana a panacea. It's still vital to pursue many of the recommendations unveiled last month by the governor's Opioid Working Group, including raising awareness, improving treatment, distributing anti-overdose drugs, and treating addiction like a disease, rather than a crime.

But the fact that Massachusetts' first medical marijuana dispensary opened this summer, with others slated to arrive in the coming months, means that marijuana could play an unexpected role in the ongoing fight against opioids and heroin.