I did 3 sessions of 8 grams in silent darkness for 3 weekends in a row and that basically "beat the devil out of me" as they say - it was very very difficult, and a lot of work, but well worth it.I've only felt the "brain haze" (I call it) once since then, I took a gram and went for a long walk in the forest, back to no haze. It's been about 7/8 months and I can feel the "haze" building in my mind again, so I plan to do another 1g in the forest sometime in the coming weeks.
However, my personal experience has been that Psilocybin != Psilocybin - the mushroom itself is super important to the process, much like Indica and Sativa have different ways of connecting you to the mind and the aether, Psilocybin (at least for me) VERY much is the same thing, and it's much starker than cannabis is. Getting into woo-woo land here so apologize: I have some concern that just "Psilocybin" isn't a good prescription, that the "spirit" that works on you is unique to the mushroom family, and that both not knowing the mushroom to prescribe and also being clinical about it (Psilocybin vs Mushroom) may not be a good direction to go in to help people with their issues. I also think that about LSD, it might work a bit for a while, but imo it's not the best tool.