The findings suggest that a “cascading chain of events” predict marijuana use problems as teens become young adults, according to the University of Pennsylvania researchers.
“Cannabis use in and of itself does not appear to lead to conduct problems or increasing attraction to peers who use cannabis,” said study co-author Dan Romer, a research director at the university’s Public Policy Center.
There are concerns that increasing legalization of marijuana in the United States will raise the risk of problems related to pot use among youth. But the study authors said their research suggests that less than one-quarter of youth who smoke pot would develop a mild marijuana use disorder. That’s about the same rate as for alcohol.
For the new study, the investigators followed almost 400 Philadelphia kids, ages 10 to 12, for eight years.
“Previous studies have not been as able to isolate the effects of cannabis use in adolescents,” Romer added in a university news release. “But because we had measurements over the entire period of adolescence, we were able to disentangle the effects of cannabis use itself from other influences.”
The findings were published online recently in the journal Addiction.
According to study lead author Ivy Defoe, “the results show that not only do conduct problems such as school truancy and theft predict cannabis use, but adolescents who display conduct problems are also drawn to cannabis-using peers.
“These affiliations predict increases in cannabis use and, eventually, cannabis use disorder, as our results show,” she added.
Defoe is a former postdoctoral fellow at Penn’s Public Policy Center.