A new study finds marijuana use does not lead to use of illicit opioids, but also is not helpful in treating opioid use disorder.

The researchers say the findings have implications for treatment of opioid use disorder, HealthDay reports. Some programs require abstinence from marijuana in order for a person to receive treatment. Others use marijuana as part of treatment for opioid use disorder.

The researchers combined the results of 10 previous studies involving almost 8,400 people prescribed medication to treat opioid use disorder (buprenorphine, methadone or naltrexone). Over 10 months, the researchers tracked the study subjects’ use of non-medical use of opioids and marijuana.

In a news release, researcher Gabriel Costa said the findings “neither confirm concerns about cannabis increasing non-medical opioid use in individuals being treated for opioid use disorder, nor do they endorse its efficacy in reducing non-medical opioid use.”

Researcher Dr. Joao P. De Aquino said the study “questions the ineffective practice of enforcing cannabis abstinence as a condition to offer life-saving medications for opioid use disorder. Our data suggests health care systems should instead adopt individualized treatment approaches which take into account each patient’s circumstances.”