Fail? I suppose that may be a way to describe the results.
To use Psilocybin on a patient who truly has mental issues sounds like a very bad idea. Dealing with the effects of that hallucinogen on a stable mind is rough enough, but a mind that may not be firmly grounded in reality may have unpredictable results.
Reminds me of L. Ron Hubbard’s Mission Earth.
I had psilocybin mushrooms back in the ‘60s when I was young. Went up to Big Sur with a friend and walked around in the woods. Delightful experience, I had no idea how truly lovely nature is. We both saw individual drops in a waterfall. Made me feel in love with the world.
As an older, physically and mentally healthy person, I think it would be lovely to have that experience again somewhere where it’s beautiful with many animals like birds, squirrels, etc. I love my life and all God’s creatures too.
Would experiences like that help a mentally ill person? Perhaps.