Some recent studies suggest that there is no increase in risk of psychosis from psychedelic use, and at worst, it causes symptoms which would have surfaced anyways to surface sooner. This isn't a reason to take psychedelics of course, it's better that one goes as long as they can without experiencing some sort of schizo-affective disorder.
My point is that people are misunderstanding the risks when they look at psychedelics and go "No way I'm taking that, I don't want to make myself schizophrenic", and then don't bat an eye when they drink a glass (or two) of wine or smoke a joint.