Overview
- Researchers in Sweden ran a randomized, double-blind Phase 2 study in 35 adults with recurrent major depression testing a single 25 mg psilocybin dose with psychotherapy against an active placebo.
- The treatment cut clinician-rated depression scores more than placebo eight days after dosing, with a mean drop of 9.7 points versus 2.4 on the MADRS scale.
- Remission at six weeks was higher with psilocybin, 53% compared with 6% for placebo, while a one-year difference between groups was not confirmed.
- Most side effects were mild and short-lived, though two people who received psilocybin developed severe, persistent anxiety that required medical care.
- To address questions raised by the small sample and weak blinding, the team will analyze PET scans and blood and spinal fluid and aim for larger, longer trials to clarify durability and mechanisms.