Previous research indicating that marijuana use is associated with depression and anxiety is being challenged by a new study that claims the opposite — that using marijuana as an adult has no correlation with the mood and anxiety orders it is typically associated with.
According to the Washington Post, a new study published Wednesday in the journal JAMA Psychiatry found that using marijuana does not cause depression or anxiety.
Researchers took a look at the records of 35,000 U.S. adults who participated in the National Epidemiological Survey on Alcohol and Related Conditions, which studied marijuana use in 2001 and 2002. In 2004 and 2005, the mental health of these participants was examined.
The study accounted for factors which might complicate the issue, looking for things like family history and possible past psychiatric disorders. Once these were considered with the data, the study concluded that “cannabis use was not associated with increased risk for developing mood or anxiety disorders.”
What marijuana use is linked with, however, is further substance-use disorders. The research indicates that adult marijuana use can lead to use of and dependence on alcohol, tobacco, marijuana and other drugs.
“The findings concerning cannabis raise the question of whether alcohol use also contributes to the risk of subsequent substance use disorders,” said the study’s lead author Mark Olfson of Columbia University. He concluded, however, that such a question is beyond the scope of the current study.
Critic Keith Humphreys, an addiction and mental-health specialist at Stanford University, notes that the study does not address a previously observed link between heavy marijuana usage and schizophrenia. He added that that connection might also be as spotty as the one linking marijuana to depression.
“I don’t know if we will ever know because it’s hard to predict rare events, and schizophrenia is rare,” he said.