Study finds no connection between young marijuana use and later mental problems

Mad in America - A long-term study that followed 408 seventh-graders for over 20 years found no association between marijuana use at a young age and an increased risk of psychosis, depression, and anxiety in adulthood. The study, published in the journal Psychology of Addictive Behaviors, was led by Jordan Bechtold of the University of Pittsburgh School of Medicine.

“There were no differences in any of the mental or physical health outcomes that we measured, regardless of the amount or frequency of marijuana used during adolescence,” Bechtold said in a statement to the American Psychological Association.

The researchers used data from the Pittsburgh Youth Study, which tracked a cohort of boys from seventh-grade into adulthood. After being randomly selected from the Pittsburgh public schools in 1987, the participants were interviewed every six months for two and half years until they were roughly 16 years old. Researchers then interviewed the participants annually for the next ten years and then again, a decade later, when they were about 36 years old.