“While a link exists, it exists mostly for people who are heavy users of THC products and who have a predisposition to psychosis. In fact, one recent study suggests that genetics could account for about 69 per cent to 84 percent of the link between cannabis and psychosis. It also bears mentioning that a majority of cannabis consumers experience neither psychosis nor go on to develop schizophrenia.”
Read here: The cannabis-psychosis debate is being driven by fear mongering, not facts – The Globe and Mail