Well, clandestine psychedelic assisted therapy has been going on for at least a few decades and seemed to be largely based on both psychedelic experiences had b

Well, clandestine psychedelic assisted therapy has been going on for at least a few decades and seemed to be largely based on both psychedelic experiences had by the therapist themselves, and trial and error - which you could argue is not too different from shamanic practice. I’m not sure how much, if any, scientific rigor was applied in the past - I hope that changes.