Unfortunately it's hardly possible to do proper case control studies with psilocybin, since the psychedelic effects cause unblinding.
This is a problem with SSRIs as well; studies have found most people can correctly guess if they’re in the study group or control group.
A true double blind study would require a drug that has similar side effects via an unrelated mechanism, but nobody has attempted that as far as I’m aware.
There was this interesting one though where they deceived patients into believing they were taking an “active placebo” instead of an SSRI, and found that the benefits went away, which is very interesting and raises a lot of questions about the true efficacy of these medications: https://www.nature.com/articles/s41398-021-01682-3.pdf
This is a problem with SSRIs as well; studies have found most people can correctly guess if they’re in the study group or control group.
A true double blind study would require a drug that has similar side effects via an unrelated mechanism, but nobody has attempted that as far as I’m aware.
There was this interesting one though where they deceived patients into believing they were taking an “active placebo” instead of an SSRI, and found that the benefits went away, which is very interesting and raises a lot of questions about the true efficacy of these medications: https://www.nature.com/articles/s41398-021-01682-3.pdf