# PSIL201 Long-term Follow-up Study: Psilocybin or Niacin / Major Depressive Disorder

> **NCT04353921** · — · TERMINATED · sponsor: **Usona Institute** · enrollment: 26 (actual)

## Conditions studied

- Major Depressive Disorder

## Interventions

- **OTHER:** No intervention will be administered as part of this study.

## Key facts

- **NCT ID:** NCT04353921
- **Lead sponsor:** Usona Institute
- **Sponsor class:** OTHER
- **Phase:** —
- **Study type:** OBSERVATIONAL
- **Status:** TERMINATED
- **Start date:** 2020-06-30
- **Primary completion:** 2022-10-18
- **Final completion:** 2022-10-18
- **Target enrollment:** 26 (ACTUAL)
- **Why stopped:** Low enrollment and inability to achieve statistical significance
- **Last updated:** 2026-05-04


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT04353921

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT04353921, "PSIL201 Long-term Follow-up Study: Psilocybin or Niacin / Major Depressive Disorder". Retrieved via AI Analytics 2026-06-09 from https://api.ai-analytics.org/clinical/NCT04353921. Licensed CC0.

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