Psilocybin
Bradley et al., Neuropsychopharmacology, 2025
- Design
- Open-label, single-arm pilot trial (NCT04932434) at an academic research center. Twelve participants with mild to moderate Parkinson's disease plus depression and/or anxiety received one 10 mg and one 25 mg oral dose of psilocybin with psychotherapy. The stated primary aim was safety, tolerability and feasibility.
- Who took part
- 12 adults (mean age 63.2 ± 8.2 years, 5 women) with mild to moderate Parkinson's disease and clinically significant depression and/or anxiety.
- Findings
- No serious adverse events, no medical intervention needed to manage the drug's effects, and no worsening of Parkinson's symptoms on the MDS-UPDRS scale. Non-motor symptom scores fell 13.8 points, motor-experience scores 7.5 and motor-exam scores 4.6. Depression scores fell 9.3 points and anxiety scores 3.8 points, with the mood gains still present at the final assessment three months after dosing.
- Limitations
- No control group and 12 participants, so expectation effects cannot be ruled out; the trial was designed for feasibility, not efficacy. Ten of 12 had treatment-emergent adverse events, most often anxiety, nausea and raised blood pressure. Motor and cognitive gains were followed only to one month. Funded by an anonymous donor.