A Phase 2 interventional study of Psilocybin and Pimavanserin in Parkinson Disease and Depression, sponsored by Joshua Woolley, MD, PhD. Recruiting at 1 site in United States. Open to participants aged 40 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-08-07.
Sponsored by Joshua Woolley, MD, PhD · Phase 2, Interventional, and Treatment
The purpose of this study is to understand whether people with Parkinson's Disease and depression have improvement in their symptoms after psilocybin therapy.
This is a randomized controlled trial of oral psilocybin therapy for depression in people with Parkinson's disease (PD). The primary goal is to examine efficacy of psilocybin therapy in this patient population. We will enroll 60 people ages 40 to 80 with clinically diagnosed early to moderate stage Parkinson's disease (Hoehn and Yahr Stage 1-3 during an "on" period), who meet criteria for moderate or greater depression severity and meet all other inclusion and exclusion criteria at screening. Participants will complete two drug administration sessions where they will each receive a dose of oral psilocybin ranging from low ("microdose") to high in a medically monitored setting with psychotherapeutic support. Participants will also complete a series of psychotherapy sessions before and after each drug administration session. Clinical assessments, neuroimaging, non-invasive brain stimulation, and peripheral blood draws will be used to quantify changes in depression, other non-motor and motor symptoms of PD, quality of life, and selected neural and blood-based biomarkers at multiple time points. Follow-up will continue to 3 months after the second session. Primary endpoints will evaluate efficacy, safety, and tolerability of study procedures. After posting of these trial results, this data will be combined with the data from the trial at Yale University (NCT07610369) for publication purposes.
4,573 studies on the registry are indexed under Parkinson Disease; 1,086 are open to participants now.
This study's planned enrollment of 60 is above the median of 40 across 3,353 interventional studies indexed under Parkinson Disease.
Browse Parkinson Disease studies →Joshua Woolley, MD, PhD is the lead sponsor of 4 studies on the registry; 2 are open to participants now.
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Exclusion Criteria:
Participants will receive one dose of psilocybin ranging from low ("microdose") to high and either pimavanserin or a placebo capsule in a medically monitored setting with preparation sessions before and integration sessions after.
Drug: Psilocybin · Drug: Pimavanserin
Participants will receive one dose of psilocybin ranging from low ("microdose") to high and either pimavanserin or a placebo capsule in a medically monitored setting with preparation sessions before and integration sessions after.
Drug: Psilocybin · Drug: Pimavanserin
Single dose of psilocybin ranging from low ("microdose") to high delivered orally in two separate drug administration sessions with psychological support and monitoring.
Also known as: 4-phosphoryloxy- N,N-dimethyltryptamine
Participants will receive either pimavanserin or placebo during their drug administration sessions.
Evaluate the efficacy of psilocybin for improving depression in people living with Parkinson's disease
Changes in depression as measured by the MADRS
Time frame: Baseline to 30 days after first drug dose
Changes in depression severity
Measured by Beck Depression Inventory-2 (BDI-2) scores
Time frame: 7 days after first drug dose to 90 days after second drug dose
Changes in clinician-assessed depression
Measured by the Montgomery-Asberg Depression Rating Scale (MADRS)
Time frame: Baseline to 90 days after second drug dose
Changes in anxiety
Measured by the Parkinson Anxiety Scale (PAS)
Time frame: Baseline to 90 days after second drug dose
Changes in PD symptom severity
Measured by the Movement Disorder Society revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS)
Time frame: Baseline to 90 days after second drug dose
Changes in Quality of Life
Measured by the 36-item Short Form survey (SF-36)
Time frame: Baseline to 90 days after second drug dose
Changes in cognitive performance
Measured by a multi-task assessment
Time frame: Baseline to 90 days after second drug dose
Safety and tolerability of psilocybin therapy for depression in people with PD
Incidence, severity, and frequency of Adverse Events (AEs) including Treatment-Emergent AEs (TEAEs) and Serious AEs (SAEs)
Time frame: Baseline to 90 days after second drug dose
Changes in clinician-rated psychotic symptoms
Measured by the Enhanced Scale for the Assessment of Positive Symptoms for Parkinson's Disease (eSAPS-PD)
Time frame: Baseline to 90 days after second drug dose
Subjective effects of psilocybin
Measured by the 5-Dimensional Altered States of Consciousness Rating Scale (5D-ASC)
Time frame: Up to 30 and 60 days after Baseline
Participant-reported acceptability of study procedures
Measured by the study-specific Treatment Satisfaction Questionnaire-Participant (TSQ-P)
Time frame: 30 days after second drug dose
Changes in peripheral inflammatory markers (exploratory)
Measured by blood-based analysis
Time frame: Baseline to 90 days after second drug dose
Changes in brain structure and function (exploratory)
Measured by Positron Emission Tomography (PET) imaging, Magnetic Resonance Imaging (MRI) and Transcranial Magnetic Stimulation (TMS)
Time frame: Baseline to 30 days after first drug dose
Changes in participant reported sleep (exploratory)
Measured by the Parkinson's Disease Sleep Scale-2 (PDSS-2)
Time frame: Baseline to 90 days after second drug dose
Changes in sleep parameters, physical activity, body temperature, and heart rate (exploratory)
Measured by using passive sensing via a wearable device
Time frame: Baseline to 30 days after first drug dose
Evaluation of treatment expectations (exploratory)
Measured by the Treatment Expectancy questionnaire consisting of 6 questions from the Stanford Expectations of Treatment Scale. Rating point scale is from 1 (Strongly disagree) to 7 (Strongly agree). Higher scores represent greater expectations of treatment benefit.
Time frame: Baseline
Evaluation of masking procedures (exploratory)
Measured by the study-specific Masking Questionnaire which includes items to assess perceived treatment assignment. Using a 7-point scale, higher scores represent greater certainty.
Time frame: Up to 30 and 60 days after Baseline
Plan to share: No
Started Aug 2024 (actual). Primary completion is estimated for Jun 2027, 34 months after the start.
Of 105 non-industry phase 2 interventional studies under Parkinson Disease, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 24 and three quarters within 59. This study's planned 34 months is close to that.
Counting every sponsor, half of 201 studies reached it within 28 months; a quarter within 16 and three quarters within 44.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Psilocybin
Joshua Woolley, MD, PhD