LSD (even small doses) is known to trigger manic episodes and schizophrenic breaks for those who suffer from such things -- oftentimes the person is not even aware they have the underlying problem until after it is triggered by drug use, which leads to the popular mythology of "folks who never came back from their trip."
Psychedelic-aware health practitioners would strongly advise anyone who has any history of schizoaffective or bipolar symptoms to avoid LSD at all costs. 'Shrooms won't hurt your brain though, and you can benefit from meta-cognitive reflection in that state just as well.