Cannabis has been hailed as a potential magic bullet in the fight against all sorts of ills, including chronic pain and depression. But it has also been called the “devil’s lettuce,” with claims that using it will lead to laziness, insanity and even murder. These polarized views can, in part, be explained by the drug’s complexity: cannabis is not a single substance but rather a mixture of more than 500 individual chemicals whose proportions vary from one plant strain to another.
Because cannabis is such a complicated chemical soup, until recently most often prepared for the black market, it has been difficult to draw clear research conclusions about whether the substance harms or helps. This assessment is particularly true in the area of addiction and mental health, where advocates believe that the drug could be the white knight of the opioid epidemic.
Some U.S. states—New York, New Jersey and Pennsylvania—have followed the lead of such advocates and explicitly approved medical cannabis as a treatment for opioid addiction. But critics of these policy decisions have argued there is not yet enough evidence to support and promote cannabis as an effective panacea. And the critics are correct: there have been no randomized controlled trials—the gold standard for testing drug effects—that have evaluated cannabis specifically for treating opioid addiction.
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Further, as argued by Keith Humphreys of Stanford University and Richard Saitz of Boston University in JAMA, substituting cannabis for opioid addiction therapies could be harmful because it would displace already established treatments, such as methadone and buprenorphine—which could be life-threatening. At this time, offering cannabis as a treatment for opioid addiction is not consistent with the practice of evidence-based medicine.
But such evidence is beginning to emerge. A recent review in Cannabis and Cannabinoid Research, for example, shows that cannabis might be able to help with the treatment of opioid symptoms such as withdrawal and cravings. The reason: biologically, the receptor systems in the brain that allow cannabis and opioids to affect us are closely related. If the goal of treatment is to reduce harm, then it makes intuitive sense to offer cannabis in the hope that opioid use will decrease. Cannabis is less dangerous than illicit opioids to both the individual and society at large. While there is a small chance that substituting a less harmful drug for a more harmful one could simply lead to a new addiction, this approach might well be a risk worth taking.
One issue complicates the equation: it’s unclear if cannabis can help people who experience opioid addiction and chronic pain. Whereas fewer than 8 percent of pain patients become addicted to opioids, people addicted to opioids have higher rates of chronic pain as compared with the general population. The effectiveness of cannabis for pain management is by no means proved: research on this question so far is relatively weak—but that could be said for most work on a drug scientists have been discouraged from studying by the government. The case is by no means closed.
So will cannabis be the cure for the opioid crisis? Not by itself, clearly: the crisis is a multilayered and multi-causal problem that demands a multipronged solution. Because opioid addiction develops as the result of many interacting biological, psychological and social factors, effective treatment modalities are needed at each level of analysis. This complexity suggests an approach that incorporates evidence-based psychological and pharmacological treatments, coupled with a system that allows people easy access, whether through family physicians, emergency departments, pain-treatment centers, safe injection sites, or outpatient and residential programs.
Despite the hype, it is absurd to think cannabis can be a remedy for all aspects of the human condition. There is, however, good reason to believe that future research will support a helpful role for it in the treatment of opioid addiction. But we are not there yet. This kind of work, especially in the form of randomized controlled trials, is sorely lacking and urgently needed. Such research should be aggressively pursued so we can say with better certainty whether cannabis belongs in the evidence-based tool kit in the fight against opioid addiction.