Reefer Madness

In the 1930's,  a movie entitled "Reefer Madness" was produced purportedly to educate young people about the dangers associated with marjuana use. It notoriously exaggerated the dangers, and has not been taken seriously in decades.

But a recent study has shown that people with a certain genetic marker who use cannabis are twice as likely to experience psychosis compared with those who use the drug but do not have the genetic marker. And among people who use the drug every day, the risk for psychosis increases sevenfold for those who have the genetic marker.

 Previous studies have linked smoking marijuana with increased risk of psychiatric disorders, such as schizophrenia. It is hoped, that the new finding could help identify which cannabis-users might be at relatively greater risk of this rare side-effect.