According to a new study, “Chronic Adolescent Marijuana Use as a Risk Factor for Physical and Mental Health Problems in Young Adult Men”, marijuana-using teen boys were not found to have more physical and mental health issues later in life compared to non-using teen boys.

The research, conducted by scientists at the University of Pittsburgh Medical Center and Rutgers University, was published by the American Psychological Association in the journal Psychology of Addictive Behaviors. According to the paper, previous studies of marijuana use “have focused primarily on respiratory, cardiac, and metabolic problems, as well as mental health problems such as depression, anxiety, and psychosis.”

The researchers decided to test the hypothesis that early and chronic use of marijuana by teens would increase the likelihood of development of those disorders. Their study group consisted of 408 teenage boys who were tracked into their mid-thirties. The subjects were identified as “low or non-users” (46 percent); “early chronic users” who started young and use heavily (22 percent); “adolescence-limited users” who quit using at adulthood (11 percent); and “late-increasing users” who started using later in life and continue to use (21 percent).

“What we found was a little surprising,” said lead researcher Jordan Bechtold, PhD, a psychology research fellow at the University of Pittsburgh Medical Center. “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.”

Researchers controlled for alcohol, tobacco, and hard drug use, socioeconomic status, health insurance coverage, and health prior to marijuana use. They found that early chronic marijuana users were no more likely than late increasing users, adolescence-limited users, or low/nonusers to experience the predicted health problems in their mid-30s.

Even when researchers ran the data without accounting for alcohol and drug use and other factors, there were no significant differences between the groups, even though teens in the early chronic group were using marijuana (on average) once per week by late adolescence and continued using marijuana approximately 3– 4 times a week in their early twenties.

“Given prior research in the area,” wrote the authors, “it was somewhat surprising that marijuana groups did not differ in the likelihood of having a psychotic disorder. Overall, data from this sample provide little to no evidence to suggest that patterns of marijuana use from adolescence to young adulthood, for the Black and White young men in the present study, were negatively related to the indicators of physical or mental health studied here.”

Russ Belville

"Radical" Russ Belville is a blogger, podcaster, and host of The Russ Belville Show, a daily two-hour talk radio show focused on the evolution of the legal marijuana industry in the United States. The program is airing live at 3pm Pacific Time from Portland, Oregon, on CannabisRadio.com, with podcast available on iTunes and Stitcher Radio. Russ began his marijuana activism in 2005 with Oregon NORML, then in 2009 went on to work for National NORML, and found and direct Portland NORML.in 2015.