This Phase IIa, placebo-controlled, double-blind trial (n=50) will study the safety, tolerability, and preliminary efficacy of a 3 mg dose of psilocybin (oral solution) in adults with generalised anxiety disorder (GAD).
Phase 2a design with screening (up to 4 weeks), a 4-week open-label run-in (psilocybin 3 mg daily), then responders randomised 1:1 to 28-day double-blind psilocybin or placebo.
Outcomes include safety and tolerability, preliminary efficacy on GAD-7 and HAM-A, cognitive testing, EEG and patient-reported outcomes; allocation is randomized with quadruple masking.
Psilocybin oral solution 3 mg daily (open-label run-in 28 days; responders randomized to 28-day double-blind phase).
Open-label run-in 28 days; responders randomised 1:1 to 28-day double-blind phase.
Sucralose oral solution once daily during double-blind phase.
Sucralose 0.2% oral solution once daily for 28 days (double-blind comparator).