There was a meta analysis recently about that topic:
Quote:
(19.08.2013) The use of LSD, magic mushrooms, or peyote does not increase a person's risk of developing mental health problems, according to an analysis of information from more than 130,000 randomly chosen people, including 22,000 people who had used psychedelics at least once.
Link to article and source of studyOf 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?