I quoted Leary on 'set and setting' the other day on an LSD history thread and mentioned Leonard Orr used to get great results with nothing more exotic than oxygen, so rather than repeat that ( https://news.ycombinator.com/item?id=21264919 ) I'll say this:
If you have a modality of therapy that works, it will work without the drug (which, at best, serves as an amplifier and a "convincer".)
If you don't have a modality of therapy that works reliably, then it's irresponsible to add drugs and hope for the best. You're banging on the side of the box hoping to reseat the vacuum tubes.
The "convincer" effect can be achieved without drugs. Not to be too mysterious but I mean hypnosis. You can e.g. quit smoking using hypnosis. It's not even hard.
I'm not against drugs per se I'm just against using them in therapy. It's irresponsible. It's like advocating zeppelins over bikes for personal transport.
(I'm great friends with Mushroom, and a little 'shroom tea can be great fun. But cramming 'im into a wee lil pill and then claiming "quit smoking" magic is in it... That's bad science and lousy magick.)