In a retrospective study of people with treatment-resistant depression, repeated psilocybin-assisted therapy sessions led to progressively stronger outcomes. About 42% of patients showed a clinically meaningful reduction in depression after one session, rising to 58% after two sessions and 67% after three or more sessions, with remission rates reaching roughly 40% by final follow-up. Benefits accumulated rather than diminished with repeat dosing, and treatments were well tolerated, with mostly mild, short-lived side effects and no serious adverse events reported.