I'd like to know the data source. When I filled out drug sureys in middle school I always said that I used heroin 5 times per day, etc. I can't imagine I was the only one. If the study is based solely on what the kids say they did, then I put a lot of doubt in it.
"Past medical studies have linked marijuana with a greater incidence of mental disorders such as depression or schizophrenia. But questions remain about whether people who smoke marijuana at a young age are already predisposed to mental disorders, or whether the drug caused those disorders."
They key word is "linked." You could also link gum chewing to smokers. You could link beans with rude behavior.
".....When I filled out drug sureys in middle school I always said that I used heroin 5 times per day, etc..."
LMAO!!!!!!!!!
Imagine the consternation you caused in our nation's busybodies. I wish I could have done that (they didn't give us such surveys when I was in middle school, circa 1971-1973).
I'd love to see the government release a survey of the incidence of mental illness among people who started DRINKING before age 12......