A single 25 mg dose of psilocybin, but not 10 mg, reduced depression scores more than a 1 mg control dose over three weeks in adults with treatment-resistant depression. In this phase 2 trial, 233 participants were randomly assigned to 25 mg, 10 mg, or 1 mg of synthetic psilocybin with psychological support. The 25 mg group showed an average 12-point drop on the MADRS depression scale versus a 5.4-point drop in the 1 mg group, a significant difference. The 10 mg group did not differ significantly from control. Response and remission rates at three weeks supported the primary result, but sustained response at 12 weeks was not significantly different.
In people with treatment-resistant depression, esketamine nasal spray outperformed quetiapine extended release across multiple measures. Sensitivity analyses using different definitions of remission and relapse consistently favored esketamine, with relative risks for the primary endpoint ranging from 1.462 to 1.737 and for the key secondary endpoint from 1.417 to 1.838. Esketamine also shortened time to first remission by 71% and confirmed remission by 66%. The robustness of the original ESCAPE-TRD trial findings was confirmed.