This double-blind, randomised, placebo-controlled trial (n=120) will investigate the interaction between psilocybin (up to 25 mg, oral) and the context of its administration in healthy volunteers with moderate-to-lower-than-average mental well-being.
Randomised, double-blind between-subjects 2×2 factorial study (n=120) testing single oral dose psilocybin (up to 25 mg) versus inactive placebo crossed with two predefined contextual (set and setting) conditions.
Primary aims are to assess interaction effects on psychological well‑being (WEMWBS) at 4 weeks and connectedness (WCS); secondary acute-experience endpoints include Emotional Breakthrough Inventory and subfactors of the Challenging Experience Questionnaire.
Healthy volunteers with limited prior psychedelic experience will be randomised 1:1:1:1 into Psilocybin/Context1, Psilocybin/Context2, Placebo/Context1, or Placebo/Context2 with single dosing and follow-up assessments.
Single oral dose up to 25 mg psilocybin administered in Context 1.
Up to 25 mg per participant
Context 1 behavioural condition
Single oral dose up to 25 mg psilocybin administered in Context 2.
Up to 25 mg per participant
Context 2 behavioural condition
Single oral inactive placebo administered in Context 1.
Inactive placebo
Context 1 behavioural condition
Single oral inactive placebo administered in Context 2.
Inactive placebo
Context 2 behavioural condition