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Opinion | Kevin P. Hill

Balance on cannabis may lead to answers on opioids

Cannabis at Harborside, a medical marijuana dispensary in Oakland, Calif.Jim Wilson/The New York Times

The United States is the midst of an opioid crisis. Ninety Americans die each day from opioid overdoses on prescription opioids, heroin, or fentanyl, and Massachusetts has not been spared. Many states are using the best available tools to battle the crisis, with an eye on developing better science and policy to put an end to the crisis. As more states implement either medical or legalized recreational cannabis policies, they should consider whether cannabis can play a role in the opioid crisis.

The evidence suggests that it might. For years, patients with chronic pain have reported that medical cannabis reduces the need to manage their pain with opioids. This anecdotal evidence is supported by a growing body of literature published in top scientific journals, including Health Affairs and the American Journal of Public Health. The scientific rationale for a relationship between cannabis and opioids is not new — cannabinoid and opioid receptors affect common brain pathways for pain and addiction.


Recent research has shown that medical or recreational cannabis policies are associated with decreased opioid use and overdoses, and deaths by overdose. A review in Health Affairs of Medicare Part D prescription data from 2010 to 2013 revealed a significant decline in pain medication prescriptions in states with medical cannabis laws compared to those without. Another study, published in the American Journal of Public Health, found that medical cannabis laws were associated with a 25 percent reduction in opioid overdose deaths. These findings were echoed by an analysis of monthly opioid-related deaths before and after the legalization of recreational cannabis in Colorado that demonstrated a significant reduction in opioid-related deaths after legalization.

Cannabis is a polarizing topic, though, so some disagree about a possible role for cannabis in the opioid crisis. The President’s Commission on Combating Drug Addiction and the Opioid Crisis chastised “an active movement to promote the use of marijuana as an alternative medication for chronic pain and as a treatment for opioid addiction,” warning of an “uninformed rush to put another drug legally on the market in the midst of an overdose epidemic.” But the commission conflated chronic pain and addiction. The evidence is building for cannabis as a tool to treat chronic pain, while there are no studies at this time that demonstrate cannabis as a treatment for opioid addiction. Cannabis use is not without risk — the effects of chronic heavy use include cognitive difficulties and addiction — but the promising results in the context of the opioid crisis should stimulate cannabis research, not slow it down.


Attorney General Jeff Sessions’ decision to afford US attorneys full discretion to enforce federal prohibition on marijuana will further stymie critically needed research. After threatening action for months, Sessions turned the legal cannabis landscape upside down by abandoning the Cole Memorandum, issued during the Obama administration, which discouraged the use of federal resources to prosecute those who abided by state cannabis laws. Sessions’ action will likely hinder all activities related to cannabis, including research.

Unfortunately, cannabis research has not kept pace with cannabis policy. Many on either side of the cannabis debate have highlighted the need for research to evaluate medical uses or safety issues prior to state votes, but research is rarely a priority afterwards. For example, the Massachusetts Cannabis Control Commission requested over $7.5 million for fiscal year 2018, but only $70,000 — less than 1 percent — for “mandated research.”


Everyone wants to put an end to the opioid crisis. The solution will likely have many parts; rigorous science will have to be a piece of it. This means we must rely upon the available evidence while pushing for more research. The evidence currently suggests a possible role for cannabis in addressing a part of the opioid crisis. We must aim to be evidence-based, not ideologically based, in order to clarify that role.

Dr. Kevin P. Hill is director of the Division of Addiction Psychiatry at Beth Israel Deaconess Medical Center, assistant professor of psychiatry at Harvard Medical School, and author of “Marijuana: The Unbiased Truth about the World’s Most Popular Weed.”