Teenagers who use cannabis recreationally are two to three times more likely to have depression and suicidal thoughts than those who don’t use it. And teens who have cannabis use disorder – which means they can’t stop using it despite health and social problems – are four times more likely to have those same thoughts and feelings.
The study was published in JAMA. It looked at information from 68,000 teens in the National Survey on Drug Use and Health.
Marijuana use was also linked to other issues including not doing well in school, skipping school, and getting in trouble with the police.
“Kids, year by year, have been moving towards a view that marijuana is safe and benign – that’s factually incorrect,” lead author of the study, Ryan Sultan, MD, an assistant professor of clinical psychiatry at Columbia University, New York, told Yahoo Life.
Dr. Sultan said he was surprised that recreational users had a much higher risk of mental health issues. “We typically think of recreational use as not being a concerning behavior.”
The study did not seek to explain the link between mental health problems and cannabis use.
“The more you use it, the more it negatively affects your thinking. That’s increasing the likelihood of depression and more suicidal thoughts,” Dr. Sultan said. “It’s feedback that spirals downward and gets to a place that really concerns us as child psychiatrists.”
Dr. Sultan said parents should talk to their children about marijuana use, depression, and anxiety.
NIDA and American Academy of Child and Adolescent Psychiatry provided funding for the study. One coauthor reported receiving grants and personal fees from several medical and sports organizations. The other authors reported no conflicts of interest.
A version of this article first appeared on WebMD.com.