A recently released paper, published online this week in JAMA Psychiatry, challenged previous results by suggesting cannabis use in adults isn’t linked with mental issues such as depression or anxiety.
The study looked at records of almost 35,000 adults in the U.S. across several years who reported cannabis use and found no correlation between mental health issues.
Controlling the results for factors such as family history and environment, researchers found that “cannabis use was not associated with increased risk for developing mood or anxiety disorders.”
Stanford University addiction and mental-health specialist Keith Humphreys said the study is “a strike against the hypothesis that cannabis uses causes mood and anxiety disorders.”
Humphreys said the study doesn’t touch on a link between heavy cannabis use and schizophrenia, the connection between which isn’t clear.
“I don’t know if we will ever know because it’s just hard to predict rare events, and schizophrenia is rare,” Humphreys said.
While the study did show no increased risk of mental health issues, it did show a connection between cannabis use and other narcotic uses, such as alcohol and tobacco.
“Within the general population, cannabis use is associated with an increased risk for several substance use disorders,” the study concluded. “Physicians and policy makers should take these associations of cannabis use under careful consideration.”