Hello, New member here. My brother was given a diagnosis of schizo-affective disorder recently at the age of 31. He has been floridly psychotic recently, telling us that he can see people's spirit/aura and sees significance in things that are coincidences etc. He had no psychotic symptoms until the age of 29. In that time, he got a PhD in physics from a top university and works as a mathematician. He has also been a user of LSD and mushrooms and pot in recent years. His most active psychosis started last month on the day he used LSD. He has been off drugs for two months now and is still a bit psychotic. My question - can the illegal drugs be to blame for psychosis? How can the psychiatrist confidently diagnose him with schizo so soon after serious hard drug abuse? They seem to assume that if you are not tripping on LSD right now, then LSD cannot be blamed for your psychosis. The doctor is recommending anti-psychotics and we are reluctant because we think/hope this is due to LSD/mushrooms/peyote. Any opinions?