Evaluating the efficacy of psilocybin-assisted psychotherapy in treatment resistant depression (EMPACT): A randomised, double blinded, 4 arm parallel adaptive trial
Randomised, double-blinded, Phase II adaptive 4-arm parallel trial (n=140) comparing three psilocybin regimens with dexamfetamine control; three oral dosing sessions (psilocybin 25 mg or dexamfetamine 7.5 mg) delivered 2–4 weeks apart with structured psychotherapy.
Details
EMPACT is a four-arm, response-adaptive randomised trial in participants with treatment-resistant depression comparing three psilocybin dosing regimens to an active dexamfetamine control; participants receive up to three blinded oral dosing sessions (25 mg psilocybin or 7.5 mg dexamfetamine) spaced 2–4 weeks apart.
Each dosing session is supported by two preparation sessions (1–2 hours each) and integration sessions after each dose (plus a fourth integration after the final dose); therapists use an ACT-informed approach and trauma-informed supportive techniques.
Primary outcomes include change in HAM-D at baseline versus 1, 3 and 6 months post final PAP cycle; the adaptive design uses response-adaptive randomisation after the initial 50 participants with interim analyses for efficacy or futility.