Overview
- The Karolinska Institutet team, whose randomized Phase II results were published Friday in JAMA Network Open, found symptom relief within two days that lasted more than three months on patient reports.
- Among 35 adults with recurrent major depression, a single 25 mg dose given with psychotherapeutic support cut scores on a standard clinician scale (MADRS) by 9.7 points at day 8 versus 2.4 with a niacin placebo.
- At six weeks, 53% of psilocybin recipients met remission criteria compared with 6% on placebo, yet by one year the between-group advantage was not confirmed because many placebo patients had also recovered.
- Blinding was largely compromised as most participants correctly guessed their assignment, and investigators warn that expectations could have boosted the measured benefit.
- Most side effects were mild and brief, though two psilocybin patients had severe, persistent anxiety that needed medical care, and planned PET scans plus blood and spinal fluid analyses aim to explain how the drug works and how long benefits last.