Cannabis Use By Methadone Maintenance Patients Associated With Fewer Opioid Overdoses

The use of cannabis by patients enrolled in a methadone maintenance treatment program is associated with fewer nonfatal opioid overdoses, according to the results of a recently published study. An abstract of the research, “Cannabis Use and Nonfatal Opioid Overdose among Patients Enrolled in Methadone Maintenance Treatment,” was published online last month by the journal Substance Use & Misuse.

To complete the study, researchers with the University of Washington, the University of Rhode Island, the VA Portland Health System, and the Oregon Health & Science University recruited patients undergoing methadone maintenance treatment (MMT) for opioid use disorder (OUD) at four clinics in Washington and southern New England. Patients were asked to complete a one-time survey, which included questions about their cannabis use over the past month.

Data from the survey was then analyzed to compare the prevalence and risk of nonfatal opioid overdose over the previous 12 months “between participants reporting frequent (at least weekly) or infrequent (once or none) cannabis use in the past month.”

Chance Of Overdose 71% Lower Among Frequent Cannabis Users

Among the 446 participants of the study, 35% reported frequent cannabis use and 7% reported nonfatal opioid overdose in the past year. The prevalence of nonfatal opioid overdose was 3% among reporters of frequent cannabis use, and 9% among respondents who reported infrequent or no cannabis use in the past month.

“Among individuals enrolled in MMT, frequent cannabis use in the past month was associated with fewer self-reported nonfatal opioid overdoses in the past year,” the researchers wrote in their conclusion.

After controlling for demographic and clinical factors, researchers determined that “the likelihood of self-reported nonfatal opioid overdose in the past year was 71% lower among reporters of frequent cannabis use in the past month.”

The researchers noted that prior studies have found lower rates of opioid use in states that have enacted liberalized cannabis legislation, but results were mixed and the association had not been analyzed in individuals. 

“To our knowledge, this is the first study to examine the association between cannabis use and opioid overdoses in individuals. The results provide preliminary evidence of a link between cannabis use and lower prevalence of opioid overdose among people enrolled in MMT,” the authors of the study wrote, as quoted by the National Organization for the Reform of Marijuana Laws NORML).

More Research Needed

The authors noted that the limitations of the study “caution against causal interpretation” of the association between cannabis use and the likelihood of nonfatal opioid overdose.

“However, these preliminary findings encourage additional research to understand how cannabis use and non-fatal opioid overdose are related,” they added.

In a release from NORML, the cannabis policy reform advocacy group noted that the research is consistent with dozens of other studies that have shown an association between cannabis use and a reduction in the use of opioids. In February, the British Medical Journal reported that improved access to medical cannabis through storefront retailers and dispensaries is associated with declines in opioid-related deaths.