Marijuana Use Increases Psychosis Risk

Theresa H. M. Moore of the University of Bristol in England and her colleagues have conducted research which concluded that having used marijuana at any point in your life increases the risk of having a psychotic episode by 40%.

This was more than twice the risk of those who have never smoked marijuana. The heavier the use, greater the chance of developing psychosis. Heavy use was defined as smoking more than 100 times in a lifetime or currently smoking marijuana weekly.There study does not definitively establish a causal relationship between marijuana and psychosis, but it’s about the best that it gets because the only way to establish causality would be to do a randomized, controlled study having some people smoke marijuana to see what happens later in life. This type of study would be unethical.

I found this study interesting because I often hear people say “there’s nothing wrong with marijuana” or “marijuana should be legal.” These findings illustrate the fact that marijuana is a drug that can have very negative effects on your life, for the rest of your life.