Psilocybin vs. traditional antidepressants — what the data actually shows

Honest comparison: the Hopkins and NYU psilocybin trials show effect sizes substantially larger than placebo — in the 0.8-1.2 Cohen's d range for depression reduction. SSRI effect sizes in placebo-controlled trials are typically 0.3-0.5 Cohen's d. The psilocybin numbers look better on paper. The caveat: the populations are different. Psilocybin trials enrolled treatment-resistant or highly selected populations; SSRI trials enrolled broader populations. Direct comparison is difficult.

The COMPASS Pathways Phase 2b trial did something more useful than the Hopkins trials for this comparison: it was a large dose-finding study with a more rigorous blinding approach and placebo-controlled design. The 25mg dose showed significant results. The 3mg dose (essentially active placebo) did not. This is dose-response data that looks like a real drug effect, not just expectation. The effect sizes still exceeded typical SSRI data.

Your psychiatrist's skepticism is reasonable even if the comparison doesn't favor SSRIs. Key legitimate concerns: (1) psilocybin trials are not long-term studies — we don't have 2-5 year data like we have for SSRIs; (2) the therapeutic model requires significant infrastructure (preparation, facilitation, integration) that SSRIs don't; (3) the blinding problem — it's nearly impossible to fully blind psilocybin because people know if they're having a psychedelic experience. Expectancy effects could inflate results. The evidence is impressive; it's not yet conclusive at the level SSRIs are.