Teenagers who used cannabis within the last year had a dramatically higher rate of developing a psychotic disorder, according to a study published Wednesday. The study, led by researchers from the University of Toronto, found an 11 times higher risk of developing a psychotic disorder among teenagers who used cannabis compared with those who did not. When the analysis was limited to just emergency room visits and hospitalizations, there was a 27-fold increase in psychotic disorders in teenagers who had used the drug.

“When I see youths with psychotic symptoms, they’re almost always using lots of cannabis,” said Dr. Leslie Hulvershorn, a child psychiatrist and chair of the psychiatry department at Indiana University who was not involved with the study. “It would be unusual to see someone present with psychotic symptoms to a hospital and not have smoked cannabis.

” The paper adds to the growing body of research that links cannabis to an increased risk of psychotic disorders, particularly in adolescence. Use of marijuana, particularly higher-potency products, has been linked to a variety of mental health disorders, including schizophrenia, anxiety and depression . “I think that there’s enough evidence out there for us to give recommendations that teens probably shouldn’t be using cannabis,” said the study’s lead author, Andre McDonald, a postdoctoral research fellow at McMaster University in Hamilton, Ontario.

“If we can somehow ask teens to delay their use u.