Teenagers who go from occasional pot smoking to weekly or daily use are two and a half times more likely to have recurrent psychotic-like experiences, a new Montreal study says.
And with legalization of recreational marijuana in Canada less than a year away, the study’s senior author says governments are ill-prepared for the fact that adolescents will interpret the policy change as proof it’s OK to smoke pot.
“Our data show that transitioning to daily or weekly use of cannabis very significantly increases adolescents’ risk of having more exaggerated and more frequent psychotic-like experiences,” Patricia Conrod, a professor at the Université de Montréal’s psychiatry department, said in an interview.
Psychotic-like experiences are defined as “experiences of perceptual aberration, ideas with unusual content and feelings of persecution.”
The study, published Wednesday in the Journal of Child Psychology and Psychiatry, is based on responses over four years from 4,000 adolescents at 31 Montreal-area high schools.