Cannabis use could help people stay on treatment for opioid addiction

published on September 20, 2018

Daily use of cannabis could help patients stay on treatment for opioid use disorder, according to new research from the BC Centre on Substance Use (BCCSU) and University of British Columbia (UBC).

Researchers interviewed 820 people initiating opioid agonist treatment (OAT) over a 20-year period between December 1996 and March 2016. They found that individuals initiating OAT who reported using cannabis on a daily basis were approximately 21% more likely to be retained in treatment at six months than non-cannabis users.

Retention in evidence-based treatment for opioid use disorder is critical in the response to the overdose crisis. People who are retained in OAT (with methadone or buprenorphine) face much lower risks of dying of an opioid overdose or other causes than people who are out of treatment. However, previous research from the BCCSU found enormous gaps in retention on OAT. In another 10-year study involving 1,615 daily opioid users in Vancouver, BC, researchers found that only one-third were retained in OAT for more than six months in 2016, the final year of the study.

“Untreated opioid use disorder is a key driver of the overdose crisis in BC and across North America,” said Dr. Eugenia Socías, research scientist at BCCSU and lead author of the study. “With cannabis use common among people with opioid use disorder, these findings highlight the urgent need for clinical research to evaluate the therapeutic potential of cannabinoids as adjunctive treatment to OAT to address the escalating opioid overdose epidemic.”

This is the first study to find a beneficial link between high-intensity cannabis use and retention in treatment among people initiating OAT.

The latest findings add to an emerging body of evidence suggesting cannabis may have positive impacts on the health and wellbeing of people who use other substances, especially opioids.

Previous research from the BCCSU has also found that using cannabis every day was linked to a lower risk of starting to inject drugs and that intentional cannabis use preceded declines in crack use among crack cocaine users.

“The therapeutic benefits of cannabis are only just beginning to be understood,” said Dr. M-J Milloy, senior author and research scientist at BCCSU. “This research suggests that cannabis could have a stabilizing impact for many patients on treatment, while also reducing the risk of overdose. Further examination of its therapeutic value and clinical application is clearly needed.”