Being as I have a cousin who developed schizophrenia because of LSD in the 70s. And being as I've been to plenty of his doctors visits, group therapy sessions, medication change meetings, so on and so forth...
The general medical consensus is that people who develop psychotic problems AFTER using acid were already prone to having them in life anyway.
The reason some people flip out and others don't, is because LSD turns a small chemical imbalance into a larger one quicker than life does.
If you don't have a chemical imbalance in the first place, LSD isn't going to give you one. If you have a family history of things like OCD or schizophrenia, then LSD probably isn't something you're going to want to try.