Press Release

First-Ever Psilocybin Clinical Trial for Treatment of Bipolar II Depression Conducted at Sheppard Pratt Reveals Promising Results


JAMA Psychiatry recently published a first-of-its-kind clinical trial conducted at Sheppard Pratt studying the efficacy and safety of a single dose of synthetic psilocybin accompanied by psychotherapy in treating individuals with treatment-resistant bipolar type II disorder (bipolar II). The study revealed promising results with 80% of participants meeting remission criteria 12 weeks after treatment.  

The 12-week, open-label trial, initiated and led by Scott T. Aaronson, MD, chief science officer of the Institute for Advanced Diagnostics and Therapeutics at Sheppard Pratt, and funded by Compass Pathways, included 15 participants aged 18 to 65 with treatment-resistant bipolar II. Each participant had experienced an episode of bipolar II for a period greater than three months and documented at least two failed pharmacological treatments within the current episode. After discontinuing psychotropic medications at least two weeks prior to the trial, participants were administered a single dose (25mg) of synthetic COMP360 psilocybin in a controlled setting. Therapists held sessions with patients during the 8-hour dosing day as well as for three sessions prior to the trial’s start and for three integration sessions post-treatment. Funding for the study will also allow for patient results to be monitored up to two years following treatment. 

In this small pilot study, there were no findings that patients had developed symptoms of psychosis during treatment and 73% of participants met remission criteria on the Montgomery Asberg Depression Rating Scale three weeks post-treatment. Eighty percent experienced remission with no increase in bipolar II symptoms such as mania, hypomania, or suicidality twelve weeks after treatment. The results of this study suggest the efficacy and safety of psilocybin in treatment of bipolar II depression, but cannot be extrapolated to the study of psilocybin to treat bipolar I disorder.

“The results we saw from this trial are encouraging and further support the clinical study of psychedelics in patients with treatment-resistant bipolar II,” said Dr. Aaronson. “One participant compared the transformation she experienced to taking a deep breath after breathing through a straw for years. These are the types of stories we are hearing from people who struggled with this disorder for years, many whom had lost hope that their bipolar II could ever be treated.”

New research in the use of psilocybin therapy also demonstrates its potential efficacy for a range of other mental illnesses including depression, obsessive-compulsive disorder, and post-traumatic stress disorder. Sheppard Pratt’s Center of Excellence for Psilocybin Research and Treatment is currently conducting clinical trials on psilocybin with psychotherapy for the treatment of anorexia, treatment-resistant depression and chronic suicidal ideation. The Institute for Advanced Diagnostics and Therapeutics brings expert clinical care of difficult-to-treat illnesses together with a center of research developing brand new treatment modalities. Patients of the institute have access to proven neuromodulation techniques and the most advanced psychopharmacology available today. For more information on the Institute for Advance Diagnostics and Therapeutics, visit

About Sheppard Pratt

Sheppard Pratt is the largest private, nonprofit provider of mental health, substance use, developmental disability, special education, and social services in the country. A nationwide resource, Sheppard Pratt provides services across a comprehensive continuum of care, spanning both hospital- and community-based resources. Since its founding in 1853, Sheppard Pratt has been innovating the field through research, best practice implementation, and a focus on improving the quality of mental health care on a global level. Sheppard Pratt has been consistently recognized as a top national psychiatric hospital by U.S. News & World Report for more than 30 years.