Safety and efficacy of psilocybin-assisted psychotherapy for Generalised Anxiety Disorder [Psi-GAD-1]: a randomised triple-blind active-placebo-controlled trial
Randomised, parallel-group Phase II trial (n≈72) of two-dose psilocybin-assisted psychotherapy (25 mg, optional escalation to 30 mg) versus diphenhydramine active-placebo (75 mg, optional escalation to 100 mg) in adults with GAD; two dosing sessions three weeks apart with preparatory and integrative therapy.
Details
This is a randomised, parallel-group, active-placebo-controlled trial testing a two-dose psilocybin-assisted psychotherapy intervention for adults with Generalised Anxiety Disorder. Participants receive preparatory psychotherapy, two supervised 8-hour dosing sessions three weeks apart, and integration psychotherapy sessions after each dosing.
Psilocybin dosing begins at 25 mg with a prespecified option to increase the second dose to 30 mg if the acute subjective response is judged limited without substantial adverse effects. The comparator arm uses diphenhydramine (75 mg; optional increase to 100 mg) as an active placebo, with identical psychological support.
Safety monitoring includes continuous observation during dosing, vital signs (heart rate, blood pressure), availability of rescue medications, and recording of adverse events/serious adverse events using CTCAE-aligned forms; primary outcome is change in HAM-A at study conclusion.