What to know
- UHN is launching PSI-PARK, a randomized clinical trial led by U of T’s Dr. Joshua Rosenblat to investigate whether psilocybin can safely treat depression in people with Parkinson’s disease.
- The trial will use a naturally derived psilocybin drug, with doses ranging from 0.5 to 25 mg.
- Depression is common among people with Parkinson’s and can respond poorly to existing antidepressants, while people with neurodegenerative diseases have mostly been excluded from psychedelic research because of safety concerns.
- The trial follows a 2025 pilot study that found sustained improvements in depression and anxiety among people with Parkinson’s, with no reported adverse side effects, and could help fill a major gap in research on psychedelic treatments for Parkinson’s-related depression.
A new clinical trial conducted by Toronto’s University Health Network could help treat depression in people with Parkinson’s disease.
The University Health Network (UHN), a public research and teaching hospital network, is sponsoring a clinical trial set to investigate the use of psilocybin to treat Parkinson’s disease-related depression.
The randomized trial, called PSI-PARK, will be led by University of Toronto associate professor and principal investigator Dr. Joshua Rosenblat, as well as researchers with UHN.
Depression is a common condition among people living with Parkinson’s and is considered a strong indication of decline and a reduced quality of life with the disease.
PEX010, a naturally derived psilocybin drug candidate, will be used in the study, supplied by Filament Health Corp.
The drug candidate is available in multiple doses for the study, of 0.5, 1, 5, and 25 mg, and was produced using Filament’s regulated extraction, purification, and stabilization methods.
With the drug, researchers will determine whether the psychedelic can be safely used in people with neurodegenerative conditions.
The condition can respond poorly to antidepressant treatments currently on the market.
Additionally, people with neurodegenerative diseases tend to be excluded from psychedelic clinical research due to safety concerns.
Because of this, the use of psilocybin as a treatment for depression in people with Parkinson’s remains largely untested.
Past data on people with mood dysfunction
The UHN’s trial comes after a pilot study from April 2025, which involved people with mild to moderate Parkinson’s disease, as well as mood dysfunction.
The study reported the first clinical research for psilocybin involving any neurodegenerative disease.
According to Rhelion Life Sciences Corp., a Toronto-based pharmaceutical research company, the study saw improvements in depression and anxiety that were sustained through final assessment, with no adverse side effects.
What this research could mean
The announcement of the UHN clinical trial comes as other researchers are also beginning randomized trials examining psilocybin for depression in Parkinson’s.
Multiple other trials across the U.S. and U.K. are registered to examine similar interactions with Parkinson’s disease and oral psilocybin.
The growing research shows a shift in psychedelic science, with researchers moving past psilocybin’s can affect mood and toward who may be able to benefit medically.
For people with Parkinson’s disease and depression, the Toronto study could help fill a significant gap in that evidence, and may produce life-altering results.
