Marijuana is one of the most versatile natural medicines in the world, and a growing number of studies indicate that pot use is generally safe. Still, it’s important to remember that the teen brain is still developing, so anything that affects the organ is potentially harmful. That appears to be the case, with a recent study linking frequent pot use to an alarmingly higher risk of psychosis in adolescents. 
In other words, if your teen is a stoner, maybe you should be concerned. If your kid only indulges occasionally, there doesn’t appear to be a serious reason to worry about psychosis.
The information regarding marijuana and psychosis is mixed. Past studies indicate that cannabis can trigger psychotic episodes, but other studies say no way – in fact, some studies show cannabis can help psychosis. Honestly, with everyone being chemically different, cannabis probably does all of that, though different for different people.
For the latest study, lead study author Josiane Bourque, of the Department of Psychiatry at the University of Montreal in Canada, and colleagues sought to determine how marijuana use in adolescence might influence the risk of psychotic-like episodes (PLEs).
“To clearly understand the impact of these results, it is essential to first define what psychotic-like experiences are: namely, experiences of perceptual aberration, ideas with unusual content and feelings of persecution.”
The team examined data on 2,566 teenagers aged 13-16 years old from Canada. Every year for 4 years, the teens completed questionnaires concerning their drug use and the occurrence of any psychiatric symptoms. The young participants underwent a series of cognitive tests that gauged their IQ, long-term memory, working memory, and inhibitory control skills.
“[Psychosis symptoms] may be infrequent and thus not problematic for the adolescent, when these experiences are reported continuously, year after year, then there’s an increased risk of a first psychotic episode or another psychiatric condition,” said Borque.
The researchers found that adolescents who increased their pot use from occasionally to weekly or daily were at 159% greater risk of having recurrent PLEs, compared with teens in the general population. 
“Although they may be infrequent and thus not problematic for the adolescent, when these experiences are reported continuously, year after year, then there’s an increased risk of a first psychotic episode or another psychiatric condition.
Our findings confirm that becoming a more regular marijuana user during adolescence is, indeed, associated with a risk of psychotic symptoms.”
Interestingly, the research team believes cannabis-related psychosis in teens may actually be the result of depression caused by marijuana. The 2 conditions have been linked in earlier research. 
“An increase in symptoms of depression – such as negative thoughts and low mood – could explain the relationship between marijuana use and increasing psychotic-like experiences in youth.”
Fellow senior study author Patricia Conrod said that preventing teen marijuana use should be a priority, but even more so when it comes to teens with an already higher risk of PLEs. 
“While preventing adolescent marijuana use should be the aim of all drug strategies, targeted prevention approaches are particularly needed to delay and prevent marijuana use in young people at risk of psychosis.”
 Daily News