Cannabis could help people cut down or stop opioid use, research shows

New research from the University of Southern California shows that cannabis might help some people stop or cut down on their opioid use.

“We interviewed 30 people who were using opioids and cannabis and injecting drugs,” said Sid Ganesh, a PhD student at USC’s medical school and lead author of the study.

The participants, who were receiving services from a methadone clinic and a syringe exchange in Los Angeles, said cannabis was a useful tool to help manage their opioid use, in part because it has become so much easier to access in recent years.

Opioid use disorder patients often have to jump through hoops to access life saving treatments such as suboxone and methadone , and the overdose-reversal drug naloxone .

The study, published in Drug and Alcohol Dependence Reports, received federal funding through the National Institute of Drug Abuse, which has more typically supported research that looks at cannabis’s harms rather than potential benefits. Notably, the study is unique because it uses qualitative data and focuses on the lived experience of people who use drugs.

Ganesh says qualitative research provides insight into what actually works for study populations and why, especially when those populations are vulnerable and dealing with all kinds of issues that might not show up in a data point. Fifty-seven percent of participants in her study were unhoused or unstably housed, and 70% made less than $2,100 a month.

“You need to understand what’s going on in people’s lives,” she said.

Any information that can help untangle the complicated relationship between opioid addiction, overdose and cannabis use is urgently necessary. Opioid overdose deaths have been climbing in recent years, killing more than 80,000 people in 2022 . Several studies suggest that cannabis legalization has helped people reduce their opioid consumption , but evidence is mixed on its impact on opioid overdose rates. Some studies find states with legal cannabis have fewer opioid overdoses, others report the opposite . Still, others say there is no difference either way .

Ryan Marino, an addiction medicine specialist and professor at Case Western Reserve University’s school of medicine, says it’s tough to know what, if any, influence cannabis legalization has on these numbers.

“Our drug supply is so toxic, overdoses have continued to increase regardless, because of the prevalence of fentanyl and constant changes in that,” Marino said.

Ganesh and her colleagues found that cannabis could help study participants get through some of the most difficult stages of quitting or cutting down on opioids. They described using it to manage withdrawal symptoms, as well as cravings and anxiety during the period following withdrawal.

”When you’re smoking weed it gets you over the hump and that urge to get high for the first time,” said one participant. “That’s what’s so special about weed.”

People who have recently quit or cut down on opioids are especially at risk for overdose because their tolerance is lower. Marino, who treats patients with opioid use disorder, says he’s seen some of his patients successfully use cannabis to get off opioids or at least use less, while others have tried it to no avail. He says the data isn’t yet there to suggest cannabis could help the majority of people struggling with opioid use disorder, but “if it helps one person to not use or not have an overdose, I mean, that’s worth more than any amount of evidence. Honestly, a life saved is a life saved.”

In order to really understand how effective cannabis could be as a treatment for opioid use disorder, researchers would need to conduct large-scale clinical trials examining the drug.

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Marino says that federal restrictions have made it extremely difficult to study cannabis this way, although that could change in the near future . One small-scale trial from 2015 did look at how cannabis might help patients stick with a detoxification treatment involving injections of naltrexone. This study found that dronabinol, a legal, synthetic form of THC, helped soothe withdrawal symptoms. The authors also tracked participants’ cannabis use after leaving residential treatment and found people who smoked their own cannabis during the outpatient phase were twice as likely to receive their second injection and complete the detox program.

The participants in Ganesh’s study weren’t necessarily using cannabis because it’s the best drug available to help with opioid addiction, but because it was the drug they were able to get.

One participant described using cannabis to cut down on fentanyl while waiting on a prescription for suboxone, which helps people quit opioids. Ganesh says that the most important takeaway from her research is that people who use opioids need better access to all kinds of harm reduction tools, including treatments like methadone and suboxone, clean syringes, naloxone and, yes, potentially cannabis.

Marino has already seen changing attitudes toward cannabis affect his patients. In the past, he’s encountered patients who were kicked out of opioid treatment programs and even cut off from their suboxone when they’ve tested positive for cannabis, which he says can cause patients to use again, be arrested, and even die of overdose. Now, he sees a possible future where cannabis is no longer a barrier to treatment, but an acceptable tool for treatment.