A nice overview of the subject: The fascinating, strange medical potential of psychedelic drugs, explained in 50+ studies.
The drugs may be helpful with addiction, obsessive compulsive disorder, end-of-life anxiety, and depression.
I found the description of the healing power of the mystical experience as "inverse PTSD" to be interesting.
Table of contents
1) Psychedelics are one of humanity’s oldest forms of medicine
2) The mystical dimension of psychedelics is part of what makes them therapeutic
3) We don’t really know why psychedelics trigger such powerful mystical experiences
4) One reason psychedelics may work: They treat the person’s context, not just their illness
5) The research is extremely early, with small sample sizes, so it’s hard to say if psychedelic drugs really are effective at all
6) There are some big risks to psychedelic drugs
7) Still, psychedelic use may eventually benefit more than the gravely ill
8) Medical psychedelic research exposes a big flaw in drug policy and funding