Marijuana and the Opioid Epidemic: Separating Fact from Fiction

Kevin A. Sabet, PhD.,

Advocates for marijuana legalization have touted cannabis as a cure-all for just about everything. Over the years, claims have been made that the drug can “kill” cancer cells, cure alcoholism and – yes – even eliminate morning sickness. So with the tragic rise in the number of opioid-related overdoses in the U.S., it’s no coincidence we’re seeing heightened promotion by the marijuana industry touting legalization as an easy solution to this deadly crisis. This promotion has coincided with national headlines pointing to a recent study claiming states with legal marijuana have lower opioid overdose rates.

When it comes to addressing our nation’s opioid epidemic, Americans deserve solutions driven by science and evidence, not ideology or anecdotal evidence. So what does the evidence show? Has marijuana really been found to reduce the opioid epidemic?  Or is this another concerted effort by the marijuana industry to leverage an issue of real concern for Americans to advance their agenda to commercialize marijuana?

The answer is that there is insufficient evidence to confirm that legalizing marijuana will reduce opioid use and overdose deaths. According to NIDA:

Some preliminary studies have suggested that medical marijuana legalization might be associated with decreased prescription opioid use and overdose deaths, but researchers don’t have enough evidence yet to confirm this finding. For example, one NIDA-funded study suggested a link between medical marijuana legalization and fewer overdose deaths from prescription opioids.1 But this study didn’t show that medical marijuana legalization caused the decrease in deaths or that pain patients changed their drug-taking behavior.2,3 A more detailed NIDA-funded analysis showed that legally protected medical marijuana dispensaries, not just medical marijuana laws, were also associated with a decrease in the following:

• opioid prescribing
• self-reports of opioid misuse
• treatment admissions for opioid addiction

Additionally, data suggests that medical marijuana treatment may reduce the opioid dose prescribed for pain patients,5,6 and a recent study showed that availability of medical marijuana for Medicare patients reduced prescribing of medications, including opioids, for their pain.7 NIDA is funding additional studies to determine the link between medical marijuana use and the use or misuse of opioids for pain.

Simply put, it is erroneous to make the claim that people who use medical marijuana are at lower risk of overdose.  As Dr. Keith Humphreys points out, this is a common “seductive logical error” called the ecological fallacy.  According to Humphreys:

Some recent studies have shown that states with more medical marijuana availability have lower rates of opioid overdose and young male suicides. This was interpreted as meaning that people who use medical marijuana are at lower risk of overdose and less likely to take their own lives. If you think that constitutes good reasoning, you should also believe that smoking and being exposed to radon reduces your risk of cancer because in the aggregate, those variables are negatively correlated with cancer rates!…

…Perhaps surprisingly, whether medical marijuana availability at the state level correlates with some other state-level indicator actually tells us nothing about how medical marijuana affects individuals. If a state-level correlation with some indicator is positive (e.g., states with more medical marijuana have higher rates of violence) the individual level relationship can still be negative (e.g., medical marijuana use makes people less violent).

This isn’t the first time one drug has been explored as a potential miracle cure for the deadly effects of another. Decades ago, doctors once sought to treat alcoholism with heroin, and heroin addiction with cocaine. Unsurprisingly, these “cures” compounded the original problem.

The good news is that we already know what policies are proven to reduce the opioid epidemic: increasing access to treatment, prioritizing prevention, and expanding education for doctors who prescribe opioids, just to name a few.  Thankfully, addressing the opioid epidemic is an area of bipartisan consensus in Washington that continues to be informed by science.  We hope it stays that way.

If you or someone you know needs help with a substance use disorder, you can find a treatment facility using SAMHSA’s treatment locator tool.