An observational study in Major Depressive Disorder, sponsored by Usona Institute. Terminated at 1 site in United States. Open to participants aged 21 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-05-04.
Sponsored by Usona Institute · Observational
This is a Phase 2 double-blind, long-term observational follow-up study of participants from Study PSIL201. Participants providing informed consent were enrolled into this study and completed web surveys and telephone interviews conducted by one central site at the following time intervals: months 3 and 6 (± 7 days for each assessment) and months 10 and 12 (± 14 days for each assessment).
2,741 studies on the registry are indexed under Depressive Disorder, Major; 559 are open to participants now.
This study's enrollment of 26 is below the median of 140 across 357 observational studies indexed under Depressive Disorder, Major.
Browse Depressive Disorder, Major studies →Usona Institute is the lead sponsor of 5 studies on the registry; none are open to participants now.
Counted across the registry records on this site, refreshed daily.
Enrollment is constrained to those participants dosed with investigational drug (psilocybin or niacin) in Study PSIL201.
Exclusion Criteria:
Participants randomized to a single oral dose of psilocybin 25 mg in Study PSIL201.
Other: No intervention will be administered as part of this study.
Participants randomized to a single oral dose of niacin 100 mg (active comparator) in Study PSIL201.
Other: No intervention will be administered as part of this study.
No intervention will be administered as part of this study.
Montgomery-Asberg Depression Rating Scale
Between-group difference in mean change from baseline (prior to dosing in PSIL201) in Montgomery-Asberg Depression Rating Scale (MADRS) to 6 months post-dosing in Study PSIL201
Time frame: 6 Months post-dosing in PSIL201
This study is terminated, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Usona Institute