Medical Marijuana: How to Prevent Addiction

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Activist Ray Turmel holds a bag of medical marijuana while he smokes a joint in Toronto on September 28, 2015. Mark Blinch/reuters

Opioid addiction has gained recent national attention in two unexpected ways. First, the California physician Lisa Tseng was sentenced to 30 years in prison for her role in the overdose deaths of patients for whom she prescribed large doses of opioids. Then the National Governors Association issued a statement in conjunction with the American Medical Association calling for action to curb the nation's "opioid epidemic."

As this opioid epidemic raises escalating concerns, many physicians like me are feeling guilty. Or at least we should be. Because it's our fault.

Fifteen years ago, a crowd of experts—including many physicians—proclaimed that opioids such as morphine were safe for use in chronic pain. We also downplayed the risk of opioid addiction.

For example, one expert statement on chronic pain management in older adults (on which I was an author) said that "Concerns over drug dependency and addiction do not justify the failure to relieve pain."

These recommendations led to more opioid use, and between 1998 and 2011 prescriptions for opioids in the U.S. doubled. That made it much easier to get access to potent opioids, creating a rapidly expanding population of people who became addicted. When prescribing was reined in, people turned to illegal drugs such as heroin, with a resulting increase in opioid-related deaths.

As we work to curb inappropriate opioid use and find treatment for all of those who have become addicted, many of us who encouraged opioid prescribing 15 years ago don't want to make the same mistake again. And yet we may be at risk of doing exactly that. Medical marijuana is growing in acceptability at an astonishing rate, and it's now legal in 23 states plus the District of Columbia. Moreover, it's under serious consideration in a half-dozen more.

Proponents of medical marijuana advertise its safety. It's natural, they say. In fact, one dispensary owner told me guilelessly, "It's perfectly safe—it's from a flower. Not like heroin." That dispensary owner ignored the fact that heroin is derived from poppies. And that poppies are also flowers.

Besides, he told me, theoretical risks of addiction don't justify withholding a potentially beneficial treatment. But that's exactly what many experts were saying about opioids 15 years ago. And we should worry about marijuana addiction.

The good news is that the risk of marijuana dependence is lower than it is for heroin (approximately 9 percent vs. 23 percent). (The term "dependence" is used to describe someone who uses marijuana regularly, even though it impairs their ability to function normally, and despite drug-related physical and psychological problems.) Nevertheless, even if marijuana addiction doesn't turn out to be as devastating as opioid addiction is, it can still result in lost jobs, damaged relationships and lost opportunities.

Even a 9 percent risk of dependence can become a public health problem if enough people use marijuana. And if there's one thing that we can predict with absolute certainty, it's that more people will use medical marijuana.

Not only is legalization gaining ground, but there is a large and growing industry that is trying to convince patients that marijuana is safe and effective. That dispensary owner who told me that medical marijuana was "perfectly safe" may have been well intentioned, but he was running a very lucrative business.

That's not unlike the financial incentive that the pharmaceutical companies had 15 years ago to promote opioid prescribing. Perdue Pharma, the company that makes Oxycontin, saw its profits increase from $45 million in 1996 to $3.1 billion by 2010. Those profits are impressive even by the standards of today's medical marijuana boom. So we can expect to hear more—and more outlandish—claims by entrepreneurs like that dispensary owner.

To be fair, there is one very important difference between marijuana and opioids. Opioids like oxycodone and heroin can cause a fatal overdose by suppressing breathing, but marijuana won't.

So a marijuana "overdose" might make you very confused and paranoid and anxious, but won't kill you. In fact, in states that have legalized marijuana, death rates from opioid overdoses have gone down, perhaps because some people are using marijuana instead of opioids.

Nevertheless, the risk of addiction is important enough that we need to take it seriously. If we had paid more attention to the risk of opioid addiction 15 years ago, we might not be in the crisis we're in now. So we have a chance to avoid the same mistakes, and we can do that in two ways.

First, there should be mandatory counseling for patients about the risks of marijuana addiction. That could come from physicians, who provide a recommendation in order to a patient to obtain access to a dispensary. Dispensaries should also be responsible for counseling because patients need only visit a physician once a year in many states to get a recommendation, but they need to visit a dispensary every time they want to buy marijuana legally.

Second, we need a national program of public health education. We can't rely solely on physicians and dispensaries to provide counseling, because in states where medical marijuana isn't legal, like in Pennsylvania, where I'm a physician, patients won't visit a dispensary.

That means everyone should be aware of the risks of addiction, because even if you don't use marijuana—and most people won't—your brother, or your daughter, or your tennis partner might. So we also need public health messaging about the risks of dependence, just as we provide for other addictive substances like tobacco and alcohol (and heroin).

Medical marijuana does offer real benefits. I'm convinced of that. And if it ever becomes legal in the state in which I practice, I'll recommend it to my patients.

But it can also cause harm. And if we ignore those potential harms, we'll risk repeating the same mistake we made 15 years ago.

David Casarett is the author of Stoned: A Doctor's Case for Medical Marijuana.