Oh agree, well said, Cassandra. Marijuana can trigger psychotic episodes in some people, but any drug can have adverse effects, even aspirin. And, as you point out, there has not been a spike in Schizophrenia nor Bipolar disorder over the past 30-40 years (at least of which I am aware). It's a question of degree, and margin of safety or risk, with any substance/drug/food etc... I'm sure you might also be referring to the recent study in the BMJ (British Medical Journal), at least I think it was there, where researches listed substances/drugs with relative risk to society and personal health. Not surprisingly, tobacco and alcohol were no 1 and 2, next came speed, crystal meth, crack, heroin was lower down etc...Marijuana was listed 8, and suprisingly (at least based upon what I know about it), they listed Ecstasy at 10 or so.... I'm surpised with that, because there was a very well done study comparing Ecstasy users to Marijuana smokers, and the people with significant Ectasy use definitely showed brain impairment on several psychological test batteries, where even regular marijuana users did not.