Single-dose psilocybin for a treatment-resistant episode of major depression (2022)

Guy Goodwin, Scott Aaronson, Oscar Alvarez, Peter Arden, Annie Baker, James Bennett, Simon Ruffell… & Ekaterina Malievskaia

This phase 2 double-blind trial investigated the effects of a single dose of synthetic psilocybin on treatment-resistant depression in adults. Participants were randomly assigned to receive either 25 mg, 10 mg, or 1 mg (control) of psilocybin, along with psychological support. The primary outcome measured was the change in depression severity, assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS), from baseline to three weeks. Results showed that the 25 mg dose significantly reduced depression scores compared to the 1 mg dose, while the 10 mg dose did not show a significant difference from the control. However, adverse events were common across all groups, including headaches, nausea, dizziness, and instances of suicidal ideation or behavior. The study concludes that although the 25 mg dose of psilocybin shows potential for reducing depression symptoms, further research with larger and longer trials is needed to confirm its efficacy and safety compared to existing treatments.