Mixing Marijuana With Opioids May Not Be Good for Mental Health

THURSDAY, Aug. 22, 2019 (HealthDay News) -- As America continues to struggle with an opioid epidemic, marijuana has been suggested by some as a safer alternative to opioid painkillers. But taking the two together may leave users vulnerable to mental health issues, a new study finds.

Not only that, researchers found that those who combined pot and opioids for pain were also more likely to abuse other drugs such as cocaine, alcohol and sedatives.

"There's been a lot of buzz that maybe pot is the new or safer alternative to opioids, so that's something we wanted to investigate," study lead author Andrew Rogers said in a University of Houston news release. He is a doctoral student in clinical psychology from the university's Anxiety and Health Research Laboratory and Substance Use Treatment Clinic.

Rogers and his colleagues recruited 450 adults who were using opioids to manage chronic pain that had lasted for at least three months. The participants answered several online questionnaires on general information about themselves, their mental health, their pain levels and use of other substances.

The researchers found that people who mixed opioids with pot had higher rates of anxiety and depression, and they were also more likely to abuse other drugs, including cocaine, alcohol, sedatives and tobacco.

But Dr. Michael Hooten, from the American Academy of Pain Medicine, noted the study doesn't prove a pot-opioid combo causes mental health issues.

For example, it's possible that individuals with existing mental health problems engaged in risky behaviors to manage their symptoms, such as combining drugs.

"I did not see any information about [participants'] baseline history of mental health problems. What they did was simply a cross-sectional assessment of symptoms," said Hooten, who wasn't involved with the study.

Still, "what this study tells us is that individuals with chronic pain that use opioids and cannabis concurrently are more likely to have mental health problems and other substance use issues, and that is very important," Hooten said.

To determine whether combining pot and opioids actually causes mental health issues, researchers would need to do a study in which baseline mental health was assessed and participants were then assigned to take either opioids or opioids and pot, Hooton said. While this may seem unethical, given the widespread use of pot, such a study would more than likely receive regulatory permission, he said.

The study also found that those who used opioids and pot together didn't have lower pain scores than those who used opioids alone.

Why?

It could be that there's a "ceiling effect," or a maximum point beyond which increased pain does not matter. Or it could be that pot doesn't actually decrease pain. "The literature on the effects of pot on pain tolerance is limited and mixed," the researchers wrote.

Overall, this study suggests that substance abuse, chronic pain and mental health are closely intertwined. Given the risks of combining substances, it may be helpful for doctors to identify and monitor patients who are co-using substances, encourage patients to stop using pot with opioids, or identify those who use pot before prescribing opioids, the researchers said.

"The findings highlight a vulnerable population of polysubstance users with chronic pain and indicate the need for more comprehensive assessment and treatment of chronic pain," said Rogers.

The study was published in July/August issue of the Journal of Addiction Medicine.

More information

The U.S. National Institute on Drug Abuse has more about marijuana.