Research library / Clinical trial
Trial of Psilocybin versus Escitalopram for Depression
Carhart-Harris R, Giribaldi B, Watts R, et al. New England Journal of Medicine 2021;384(15):1402-1411
This Imperial College London trial compared psilocybin with escitalopram, a standard SSRI antidepressant, in 59 people with moderate-to-severe depression. One group had two 25 mg psilocybin sessions three weeks apart plus a daily dummy pill; the other had two token 1 mg doses plus daily escitalopram. Everyone received psychological support. On the main measure, a self-rated depression score at six weeks, the two treatments were not significantly different. More people in the psilocybin group responded or went into remission, and other secondary measures also leaned towards psilocybin, but these extra comparisons were not statistically adjusted and should be treated as hints rather than findings. Side effects were similar. The authors say larger, longer trials are needed to know how psilocybin compares with existing antidepressants.
What it found
- Primary outcome: QIDS-SR-16 fell 8.0 points with psilocybin vs 6.0 with escitalopram; the difference was not significant (P = 0.17)
- Response: 70% vs 48%; remission: 57% vs 28%
- Most secondary outcomes favoured psilocybin but were not corrected for multiple comparisons
- Adverse events occurred at similar rates in both groups