Psychedelics are certainly not drugs in the antibiotic sense; they don't seek out depression-causing neurons and cure them or anything remotely like that.
Rather, psychedelic drugs offer a means for the user to "get out of their head" for a bit. In the right set and setting, the experience offers an opportunity for intense introspection. “Psychedelics probably work in addiction by making the brain function more chaotically for a period — a bit like shaking up a snow globe — weakening reinforced brain connections and dynamics.” It is the experience, not the drug, which causes a fundamental shift in attitude/mindset/worldview, and that is what "cures" the illness.
Rather, psychedelic drugs offer a means for the user to "get out of their head" for a bit. In the right set and setting, the experience offers an opportunity for intense introspection. “Psychedelics probably work in addiction by making the brain function more chaotically for a period — a bit like shaking up a snow globe — weakening reinforced brain connections and dynamics.” It is the experience, not the drug, which causes a fundamental shift in attitude/mindset/worldview, and that is what "cures" the illness.