Con
“It is conceivable that excessive use of cannabis sometimes contributes to acute schizophrenic episodes. But it is difficult to believe that cannabis is a strong risk factor for this disorder, because there is no evidence that the incidence of schizophrenia has risen dramatically over the past 50 years, in parallel with the huge increase in cannabis use.
Young schizophrenic patients are often heavy cigarette smokers too, but no-one would suggest that tobacco causes schizophrenia.”
Dec. 27, 2002