It's pretty commonly stated as fact in the psychedelic community that, while psychedelics are very safe, they should not be used by people predisposed towards psychotic disorders for fear of triggering severe, long-term mental illnesses.

Can anyone find me any papers that suggest that is the case? Is there any scientific evidence to support the idea that people with schizophrenia, bipolar disorder or any other kind of psychotic disorder should be especially afraid of psychedelics?

Blessings
~ND

Unfortunately I can't help to answer your question, but I would be interested to know the answer to this as well.

There was a meta analysis recently about that topic:



Link to article and source of study

Of cause this is only statistical and it could very well mean, that it helps for example 5% of users with their mental health and drives a small proportion (let's say 0,5%) is predispositioned users into madness. The overall statistical impression would be that there are beneficial effects (4,5% less mental health problems with users).
I remember reading something in a book from Stanislav Grof, that he had observed no lasting negative effects in all the clinical sessions with LSD that he or his collegues had conducted.

So there is some statistical evidence against this claim and some anecdotal evidence for both sides. What to make of it?