Single-Dose Psilocybin Treatment for Major Depressive Disorder: A Randomized Clinical Trial

Abstract

Importance: Psilocybin shows promise as a treatment for major depressive disorder (MDD).

Objective: To evaluate the magnitude, timing, and durability of antidepressant effects and safety of a single dose of psilocybin in patients with MDD.

Design, setting, and participants: In this phase 2 trial conducted between December 2019 and June 2022 at 11 research sites in the US, participants were randomized in a 1:1 ratio to receive a single dose of psilocybin vs niacin placebo administered with psychological support. Participants were adults aged 21 to 65 years with a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition diagnosis of MDD of at least 60 days' duration and moderate or greater symptom severity. Exclusion criteria included history of psychosis or mania, active substance use disorder, and active suicidal ideation with intent. Participants taking psychotropic agents who otherwise met inclusion/exclusion criteria were eligible following medication taper. Primary and secondary outcomes and adverse events (AEs) were assessed at baseline (conducted within 7 days before dosing) and at 2, 8, 15, 29, and 43 days after dosing.

Interventions: Interventions were a 25-mg dose of synthetic psilocybin or a 100-mg dose of niacin in identical-appearing capsules, each administered with psychological support.

Main outcomes and measures: The primary outcome was change in central rater-assessed Montgomery-Asberg Depression Rating Scale (MADRS) score (range, 0-60; higher scores indicate more severe depression) from baseline to day 43. The key secondary outcome measure was change in MADRS score from baseline to day 8. Other secondary outcomes were change in Sheehan Disability Scale score from baseline to day 43 and MADRS-defined sustained response and remission. Participants, study site personnel, study sponsor, outcome assessors (raters), and statisticians were blinded to treatment assignment.

Results: A total of 104 participants (mean [SD] age, 41.1 [11.3] years; 52 [50%] women) were randomized (51 to the psilocybin group and 53 to the niacin group). Psilocybin treatment was associated with significantly reduced MADRS scores compared with niacin from baseline to day 43 (mean difference,-12.3 [95% CI, -17.5 to -7.2]; P <.001) and from baseline to day 8 (mean difference, -12.0 [95% CI, -16.6 to -7.4]; P < .001). Psilocybin treatment was also associated with significantly reduced Sheehan Disability Scale scores compared with niacin (mean difference, -2.31 [95% CI, 3.50-1.11]; P < .001) from baseline to day 43. More participants receiving psilocybin had sustained response (but not remission) than those receiving niacin. There were no serious treatment-emergent AEs; however, psilocybin treatment was associated with a higher rate of overall AEs and a higher rate of severe AEs.

Conclusions and relevance: Psilocybin treatment was associated with a clinically significant sustained reduction in depressive symptoms and functional disability, without serious adverse events. These findings add to increasing evidence that psilocybin-when administered with psychological support-may hold promise as a novel intervention for MDD.

Trial registration: ClinicalTrials.gov Identifier: NCT03866174.

Conflict of interest statement

Conflict of Interest Disclosures: Dr Raison reported receiving personal fees from Usona Institute and grants to Usona Institute from Dr. Bronner's All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen Foundation, Tiny Blue Dot Foundation, Turnbull Family Foundation, and William A. Linton during the conduct of the study and personal fees from Novartis, Sage/Biogen, Emory Healthcare, and Vail Health outside the submitted work. Dr Sanacora reported receiving grants from Usona Institute during the conduct of the study and personal fees from Ancora/Embark, Aptinyx, Atai, Axsome Therapeutics, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Clexio, Cowen, Denovo Biopharma, ECR1, EMA Wellness, Engrail Therapeutics, Gilgamesh, Intra-Cellular Therapies, Janssen, KOA Health, Levo Therapeutics, Lundbeck, Merck, MiCure, Navitor Pharmaceuticals, Neurocrine, Novartis, Noven Pharmaceuticals, Otsuka, Perception Neuroscience, Praxis Therapeutics, Relmada Therapeutics, Sage Pharmaceuticals, Seelos Pharmaceuticals, Taisho Pharmaceuticals, Valeant, Vistagen Therapeutics, and XW Labs; equity in Freedom Biosciences, Biohaven Pharmaceuticals, and Tetricus; and grants from Janssen and Merck outside the submitted work and having a patent for #8,778,979 issued from Biohaven for glutmatergic drugs and a patent for 047162-7177P1 (00754) pending from Freedom for combination of immunemodulating and glutamatergic treatments. Dr Woolley reported receiving grants from UCSF Research Allocation Program during the conduct of the study and personal fees from Alexander Shulgin Research Institute, Alvarius, Boxer Capital, Filament Health, Gilgamesh Pharmaceuticals, Guidepoint, Silo Pharmaceuticals, and Travistock Company outside the submitted work. Dr Heinzerling reported working for Usona Institute as a site primary investigator during the conduct of the study and receiving personal fees from MindMed outside the submitted work. Dr Dunlop reported receiving grants from Usona Institute during the conduct of the study and grants from Compass Pathways and Boehringer Ingelheim and personal fees from Cerebral Therapeutics, Otsuka, NRx Pharmaceuticals, Myriad Neuroscience, Sage, and the Department of Defense outside the submitted work. Dr R. Brown reported receiving grants from Usona Institute during the conduct of the study. Dr Robison reported receiving grants from Usona Institute during the conduct of the study and grants from MindMed, Janssen, Merck, Neurocrine Biosciences, Alto Neuroscience, Clexio Biosciences, and Otsuka and personal fees from Janssen and MAPS Public Benefit Corporation outside the submitted work. Dr Gukasyan reported receiving grants from Usona Institute during the conduct of the study and grants to support the Center for Psychedelic and Consciousness Research from Steven and Alexandra Cohen Foundation, Tim Ferriss, Matt Mullenweg, Craig Nerenberg, and Blake Mycoskie outside the submitted work. Dr Nayak reported receiving philanthropic support for Hopkins Center for Psychedelic and Consciousness Research from Steven and Alexandra Cohen Foundation, Tim Ferriss, Matt Mullenweg, Blake Mycoskie, and Craig Nerenberg outside the submitted work. Dr Kelmendi reported receiving nonfinancial support from Usona Institute and grants from Yale University during the conduct of the study and grants from NIMH outside the submitted work. Dr Sloshower reported receiving personal fees from Usona Institute outside the submitted work. Dr Penn reported receiving grants from Usona Institute during the conduct of the study and grants from Multidisciplinary Association for Psychedelics Studies, Filament; personal fees from Compass Pathways, Mindmed, and Alexander Shulgin Research Institute; and serving on an advisory board or steering committee or teaching for Tactogen, Osmind, North American Center for Continuing Medical Education, California Institute for Integral Studies, and Berkeley Center for Psychedelics outside the submitted work. Dr Kelly reported having stock in MindMed, Numinus Wellness, and Noetic Fund outside the submitted work. Dr Nicholas reported receiving funding support from Usona Institute during the conduct of the study and personal fees from MindMed and Multidisciplinary Association for Psychedelic Studies Public Benefit Corp outside the submitted work. Dr Tarpley reported receiving grants to Usona Institute from Dr. Bronner's All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen, Tiny Blue Dot Foundation, Turnbull Family Foundation, and William A. Linton and personal fees from Usona Institute (salaried employee) during the conduct of the study. Dr Utzinger reported receiving grants from Dr. Bronner’s All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen Foundation, Tiny Blue Dot Foundation, Turnbull Family Foundation, William A. Linton and personal fees from Usona Institute as a salaried employee during the conduct of the study and personal fees from Promega Corporation as a salaried employee; and spouse being a board member of or owning shares in Cylerity Corporation, HealthBridge Financial, Concord Health, and Ambershore Group and being a board member on the Board of Psychedelic Medicines and Therapies, which aims to develop a credentialing process for licensed health care professionals, and a guest faculty member for CIIS and Synthesis, both educational organizations that developed training programs to educate future clinicians/facilitators in psychedelic medicine. Dr Lenoch reported receiving grants to Usona Institute from Dr. Bronner's All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen Foundation, Tiny Blue Dot Foundation, Turnbull Family Foundation, and William A. Linton and personal fees from Usona Institute as a salaried employee during the conduct of the study. Dr Warchol reported receiving grants from Dr. Bronner's All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen Foundation, Tiny Blue Dot Foundation, Turnbull Family Foundation, and William A. Linton and personal fees from Usona Institute as a salaried employee during the conduct of the study. Dr Gapasin reported receiving grants from Dr. Bronner's All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen Foundation, Turnbull Family Foundation, and William A. Linton and personal fees from Usona Institute as a salaried employee during the conduct of the study. Dr Davis reported receiving grants to Usona Institute from Dr. Bronner's All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen Foundation, Tiny Blue Dot Foundation, Turnbull Family Foundation, and William A. Linton and personal fees from Usona Institute as a salaried employee during the conduct of the study. Dr Nelson-Douthit reported receiving personal fees from Usona Institute during the conduct of the study. Dr Linton reported receiving grants to Usona Institute from Dr. Bronner's All-One, Fournier Family Foundation, Good Ventures, Steven and Alexandra Cohen Foundation, Tiny Blue Dot Foundation, Turnbull Family Foundation, and William A. Linton during the conduct of the study; receiving travel expenses from Usona Institute outside the submitted work; and being executive director of Usona Institute and CEO and chairman of Promega Corporation (Life Science supplier). Dr Ross reported receiving grants from Usona Institute during the conduct of the study and grants from National Institute on Drug Abuse, National Cancer Institute, Heffter Research Institute, Council on Spiritual Practices, Multidisciplinary Association of Psychedelic Studies, Reset Pharmaceuticals, and MindMed outside the submitted work and being listed as a co-inventor in patent applications related to the use of psilocybin to treat psychiatric and existential distress in cancer, filed by New York University Grossman School of Medicine and licensed by Reset Pharmaceuticals (N420838US and N419987US). Dr Griffiths reported receiving grants and partial salary support from Johns Hopkins Center for Psychedelic and Consciousness Research during the conduct of the study and personal fees from Heffter Research Institute for serving on the board of directors outside the submitted work. No other disclosures were reported.

Figures

Figure 1.. Participant Flow in a Study of Single-Dose Psilocybin Treatment for Major Depressive Disorder

aIncludes all potential participants from the point of telephone screening. bOne participant randomized to receive psilocybin received niacin and was included in the niacin group for the safety population. cReasons for exclusion included missing day 8 or day 43 central rater Montgomery-Asberg Depression Rating Scale assessments or major protocol deviations. See eFigure 1 in Supplement 3 for additional details.

Figure 2.. Change in Montgomery-Asberg Depression Rating Scale (MADRS) Score by Treatment Group

A, Results from mixed model for repeated measures adjusted for baseline score, site, sex, and treatment-resistant depression. Error bars represent 95% CIs; point labels are P values for treatment difference for primary (day 43) and key (day 8) secondary end points in the intent-to-treat population. B, Raw value participant change values with means indicated with diamonds and medians indicated by the bar in the boxes. The boxes show the IQR and the whiskers extend from the boxes to indicate the most extreme point that is less than or equal to 1.5 times the IQR. See eFigure 2 in Supplement 3 for additional details.