Major Depressive DisorderNCT04353921
PSIL201 Long-term Follow-up Study: Psilocybin or Niacin / Major Depressive Disorder
An observational study of Major Depressive Disorder, run by Usona Institute at 1 site in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 21 to 65 years
- Conditions the study is for
- Major Depressive Disorder
- Type of treatment
- Pill or oral medicine
- How many people
- 26 participants
- Where
- 1 siteUnited States
- Study dates
- 30 Jun 2020to 18 Oct 2022
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Enrollment is constrained to those participants dosed with investigational drug (psilocybin or niacin) in Study PSIL201.
Who may be able to join
- Enrollment and randomization in Study PSIL201
- Ability and willingness to provide informed consent prior to initiation of any study-related procedures
Who cannot join
- Inability or unwillingness to complete study procedures, including regular completion of web surveys and telephone interviews with study personnel
Trial locations and contacts
1 site in 1 country.
United States1 site
Innovative Clinical Research, Inc. (formerly Segal Trials)
Lauderhill, Florida, 33319
About this study
Official title: A One-Year Observational Follow-up Study of Participants With Major Depressive Disorder Following a Randomized, Double-Blind Single-Dose of Psilocybin or Niacin-Control
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).
- Conditions
- Major Depressive Disorder
- Being tested
- No intervention will be administered as part of this study.
- Medical subject headings
- Depressive Disorder, Major
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No intervention will be administered as part of this study.Other
No intervention will be administered as part of this study.
| Study group | Role | What they receive |
|---|---|---|
| Single-Dose of Psilocybin | Participants randomized to a single oral dose of psilocybin 25 mg in Study PSIL201. Receives: Other: No intervention will be administered as part of this study. | |
| Niacin-Control | Participants randomized to a single oral dose of niacin 100 mg (active comparator) in Study PSIL201. Receives: Other: No intervention will be administered as part of this study. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 6 Months post-dosing in PSIL201
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Apr 2020
- Study start30 Jun 2020
- Primary completion18 Oct 2022
- Study completion18 Oct 2022
Why it stopped: Low enrollment and inability to achieve statistical significance
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Major Depressive DisorderStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Other
- Enrolment
- 26 participants (actual)
Sponsor and investigators
- Lead sponsor
- Usona Institute
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Charles Raison, MD, Study director, Usona Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04353921
- Sponsor's protocol ID
- PSIL201-LTFU
- Status last verified
- Apr 2026
- First submitted
- 16 Apr 2020
- Last updated
- 4 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A One-Year Observational Follow-up Study of Participants With Major Depressive Disorder Following a Randomized, Double-Blind Single-Dose of Psilocybin or Niacin-Control
- ClinicalTrials.gov ID
- NCT04353921
- Acronym / sponsor ID
- PSIL201-LTFU
- Conditions
- Major Depressive Disorder
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: Low enrollment and inability to achieve statistical significance
- Enrolment
- 26 participants (actual)
- Lead sponsor
- Usona InstituteUniversity, hospital or other
- Study start
- 30 Jun 2020 (actual)
- Primary completion
- 18 Oct 2022 (actual)
- Study completion
- 18 Oct 2022 (actual)
- First posted
- 21 Apr 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
Study design
- Observational model
- Cohort
- Time perspective
- Other
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Single-Dose of Psilocybin | – | Other: No intervention will be administered as part of this study.Participants randomized to a single oral dose of psilocybin 25 mg in Study PSIL201. |
| Niacin-Control | – | 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. |
Who may qualify
- Ages
- 21 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Enrollment is constrained to those participants dosed with investigational drug (psilocybin or niacin) in Study PSIL201.
Key inclusion criteria (2 listed)
- Enrollment and randomization in Study PSIL201
- Ability and willingness to provide informed consent prior to initiation of any study-related procedures
Key exclusion criteria (1 listed)
- Inability or unwillingness to complete study procedures, including regular completion of web surveys and telephone interviews with study personnel
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No intervention will be administered as part of this study.No intervention will be administered as part of this study. | Other | Niacin-Control, Single-Dose of Psilocybin |
Primary outcome
Montgomery-Asberg Depression Rating Scale
Time frame: 6 Months post-dosing in PSIL201
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
Results and safety
The study was stopped early (reason given: Low enrollment and inability to achieve statistical significance). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 May 2026.
Related trials for Major Depressive Disorder
Not yet recruiting
Preventive and Personalized Digital Emotion Regulation Skills Intervention to Reduce Depression and Anxiety in Youths With Adverse Childhood Experiences
Adverse Childhood Experience, Depression / Major Depressive Disorder
RecruitingPhase 4
Biomarker-Guided Antidepressant Selection
Depression - Major Depressive Disorder, Treatment-resistant Depression (TRD)
Recruiting
Targeting Network Dysfunction in Apathy of Late-life Depression Using Digital Therapeutics
Major Depressive Disorder, Apathy
RecruitingObservational study
Student Precarity and Psychiatry
Depressive Disorder, Major, Generalized Anxiety Disorder
Not yet recruiting
Acute Intermittent Hypoxia Therapy for Depression
Major Depressive Disorder (MDD)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Charles Raison, MD study director
Usona Institute
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Major Depressive Disorder, run by Usona Institute at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 4 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: Low enrollment and inability to achieve statistical significance). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Montgomery-Asberg Depression Rating Scale (time frame: 6 Months post-dosing in PSIL201). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 May 2026.