I'm not sure that's alcohol acting as a stimulant so much as alcohol removing mental barriers that prevent people from acting in a certain way. The depressant effect in fact helps to moderate the worst impulses for most people. Which is why drinks like Four Loco that combine a stimulant with alcohol end up being more dangerous than expected. Not only do you lose your "that's a dumb idea, I shouldn't do it" part of your brain, but you also have the energy to act on the impulse.

Psilocybin has known physiological affects on the body and on the brain. We see very clearly differences in how the brain functions on psilocybin.

It's absolutely not a placebo. That, or the definition of the word is being stretched such that all meaning is lost.

Placebos also have known physiological effects on the brain and there are clear differences when taking a pink placebo vs a blue one: https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

This is not to downplay the effects of psychadelics - I've taken plenty and of course the psychoactive effects are undeniable. But the effects are from far more than just the chemicals. For example smoked DMT hallucinations are very different than Ayahuasca, despite the two being the same chemical.

Hmm, I see what you are saying. I'd like to see a comparison between the effects of established placebos on the brain versus psilocybin. My hunch is that the mechanisms are quite different, but maybe there are some interesting similarities.