Clinical TrialDepressive DisordersPsilocybinPsilocybinCompleted

Psilocybin Therapy for Depression and Anxiety in Parkinson’s Disease (PDP)

Open-label, single-arm pilot study (n=12) of two supervised oral psilocybin sessions (10 mg then 25 mg, ~2 weeks apart) for depression and anxiety in people with Parkinson's disease; primary outcomes safety, tolerability, and feasibility.

Target Enrollment
12 participants
Study Type
Phase II interventional
Design
Non-randomized

Detailed Description

This open-label single-group pilot study tests the safety, tolerability, and feasibility of psilocybin therapy in people with early-stage Parkinson's disease who have depressive or anxious disorders.

Participants receive preparation sessions, then a first supervised 10 mg oral psilocybin session; those without significant adverse events may receive a second supervised 25 mg session about two weeks later. Psychological support and medical monitoring are provided during dosing.

Follow-up visits continue to three months after the second dosing to assess safety, Parkinson's and psychiatric symptoms, and feasibility of procedures; primary endpoints focus on adverse events and tolerability.

Study Protocol

Preparation

sessions

Dosing

2 sessions

Integration

sessions

Therapeutic Protocol

support

Study Arms & Interventions

Psilocybin therapy

experimental

Open-label single-group psilocybin therapy with preparation and integration sessions; one or two oral dosing sessions approximately two weeks apart.

Interventions

  • Psilocybin10 mg
    via Oral• single dose

    First session: 10 mg oral psilocybin with psychological support and monitoring.

  • Psilocybin25 mg
    via Oral• single dose

    Second session (conditional, ~2 weeks later): 25 mg oral psilocybin with psychological support and monitoring.

Participants

Ages
40 – 75
Sexes
Male & Female

Inclusion Criteria

  • Age 40 to 75
  • Comfortable speaking and writing in English
  • Clinically diagnosed early stage Parkinson's Disease (Hoehn and Yahr Stage 1-3 during an "off" period) who meet DSM-5 criteria for a depressive or anxious disorder and meet all other inclusion and exclusion criteria at screening
  • Currently experiencing depression and/or anxiety (a formal diagnosis is not necessary)
  • Able to attend all in-person visits at UCSF as well as virtual visits
  • Have a care partner/support person available throughout the study
  • Have an established primary care provider, neurologist, or psychiatrist

Exclusion Criteria

  • Psychotic symptoms involving loss of insight
  • Significant cognitive impairment
  • Regular use of medications that may have problematic interactions with psilocybin, including but not limited to dopamine agonists, MAO inhibitors, N-methyl-D-aspartate (NMDAR) antagonists, antipsychotics, and stimulants
  • A health condition that makes this study unsafe or unfeasible, determined by study physicians

Primary Results(1 publication)

Participants

N = 12Mean age: 63.2 across armsR. et al. 2025 →

Adverse Events (from all publications)

Arm / GroupnAny TEAESevereSeriousDiscont.
Psilocybin therapyexperimental1210(83.3%)2(16.7%)0(0.0%)—

* The paper reports TEAE counts for two doses (10mg and 25mg) separately in Table 2. The summary in the abstract and results section provides the aggregate for the 12 participants. Two participants experienced severe anxiety. No serious adverse events (SAEs) were reported. Suicidal ideation was reported but explicitly not considered a serious AE.

Study Details

Locations

University of California, San Francisco — San Francisco, California, United States

Related Publications

Psilocybin therapy for mood dysfunction in Parkinson's disease: an open-label pilot trial

Published
Authors
Bradley, E. R., Sakai, K., Fernandes-Osterhold, G., Szigeti, B., Ludwig, C., Ostrem, J. L., Tanner, C. M., Bock, M. A., Llerena, K., Finley, P. R., O'donovan, A., Rafael, J., Zuzuarregui, P., Busby, Z., Mckernan, A., Penn, A. D., Wang, A. C. C., Rosen, R. C., Woolley, J. D.

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