(CBS) Advocates of medical marijuana say pot has all sorts of health benefits. Maybe so, but a new study from Australia suggests that smoking pot can drive some people crazy - or at least make them go crazy sooner than they would have if they had never picked up the pipe.
The study, published online in "Archives of General Psychiatry," shows that potheads develop severe mental illnesses like schizophrenia about 2.7 years earlier than people who don't use marijuana.
The link between smoking pot and mental illness appears strongest in children 12 to 15 years of age, Reuters reported. They develop mental illnesses that might not have shown up until their late teens or twenties - if they showed up at all.
"The results of this study provide strong evidence that reducing cannabis use could delay or even prevent some cases of psychosis," study author Dr. Matthew Large, of the University of New South Wales, said in a written statement.
What explains the link between marijuana use and severe mental illness? One possibility, according to Dr. Large, is that pot smoking actually causes psychosis. Other possibilities, he said, are that pot might hasten the onset of psychotic symptoms in vulnerable people - or make symptoms of psychosis worse.
But other scientists say there are alternative explanations.
Michael Rice, a psychiatric nurse practitioner at the University of Nebraska Medical Center in Omaha, told HealthDay that people who are predisposed to schizophrenia might gravitate to smoking pot because it has a beneficial anti-inflammatory effect.
Whatever the explanation, Dr. Large and his colleagues are eager to publicize the risks pot smoking poses to young children, writing "Even if the onset of psychosis were inevitable (for a particular individual), an extra two or three years of psychosis-free functioning could allow many patients to achieve the important developmental milestones," MSNBC reported.
"I'm not a marketing expert," Large said, "but we have to find a way to tell young kids to hold off."
WHAT DO YOU THINK? DO THE RISKS OF SMOKING POT OUTWEIGH THE PURPORTED BENEFITS?