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A Study of Psilocybin for Major Depressive Disorder (MDD)

A Randomized, Double-Blind Study of Single-Dose Psilocybin for Major Depressive Disorder (MDD)

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03866174
Enrollment
347
Registered
2019-03-07
Start date
2020-01-23
Completion date
2022-06-28
Last updated
2026-04-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Depressive Disorder, Major

Keywords

Psilocybin, Psychedelics, Depression, MDD

Brief summary

One hundred participants, ages 21 to 65, who meet Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for major depressive disorder (MDD) will be stratified by study site and randomized with a 1-to-1 allocation under double-blind conditions to receive a single 25 mg oral dose of psilocybin or a single 100 mg oral dose of niacin. Niacin will serve as an active placebo. The purpose of this study is to evaluate the potential efficacy of a single 25 mg oral dose of psilocybin for MDD compared to the active placebo in otherwise medically-healthy participants, assessed as the difference between groups in changes in depressive symptoms from Baseline to Day 43 post-dose.

Detailed description

Major depressive disorder (MDD) has become a health crisis of epidemic proportions in the modern world. One in six individuals in the United States will experience an episode of major depression in his or her lifetime, and it is estimated that major depression will rank second after cardiac disease as a cause of international medical morbidity by the year 2020. Depression is associated with greater disability than are most other chronic illnesses and is a risk factor for mortality. Additionally, depression predicts the later development of a number of medical conditions, including cardiac and cerebrovascular disease, hypertension, diabetes, obesity, metabolic syndrome, dementia, and cancer. Unfortunately, most patients with depression do not experience a complete resolution of symptoms with antidepressant treatment. Partial-but incomplete-response to antidepressants is associated with an increased risk of full symptomatic relapse (even when on therapy) and a worse long-term disease course. Combined with the high prevalence and significant disability associated with MDD, the fact that currently available treatments are not fully adequate highlights the tremendous need to identify novel treatment strategies. Data suggest that psilocybin may have behavioral effects relevant to the treatment of depression and recent studies also suggest that psilocybin may possess antidepressant properties. To further assess the effects of psilocybin on MDD signs and symptoms, this trial will enroll 100 participants, ages 21 to 65, who meet criteria for MDD. Participants will be stratified by study site and randomized with a 1-to-1 allocation under double-blind conditions to receive a single 25 mg oral dose of psilocybin or a single 100 mg oral dose of niacin. Niacin will serve as an active placebo. To enhance participant safety, a Set and Setting (SaS) protocol will be utilized similar to the protocol that has been used in all modern studies of psilocybin. The SaS protocol for this study includes: 1) a period of preparation with session Facilitators prior to dosing; 2) administration of study medications in an aesthetically pleasing room under the supervision of two Facilitators who are present throughout the session; and 3) three post-dose integration sessions during which participants are encouraged to discuss their intervention experience with the Facilitators. The SaS protocol will be identical for those randomized to psilocybin or active placebo. The primary objective of this study is to evaluate the potential efficacy of a single 25 mg oral dose of psilocybin for MDD compared to the active placebo (niacin), assessed as the difference between groups in changes in depressive symptoms from Baseline to Day 43 post-dose.

Interventions

DRUGPsilocybin

The psilocybin used in this study is synthetically manufactured in a laboratory and meets quality specifications suitable for human research use. The active drug is encapsulated using a hydroxypropyl methylcellulose (HPMC) capsule and contains 25 mg of psilocybin.

DRUGNiacin

The active placebo is encapsulated using a HPMC capsule and contains 100 mg of pharmaceutical grade niacin.

OTHERSet and Setting (SaS) Protocol

The SaS Protocol prescribes 6-8 hours of preparatory meetings with two facilitators prior to dosing, a 7-10 hour dosing session in a comfortable room under the supervision of the same two facilitators, and 4 hours of post-dose integration sessions with facilitators. During the dosing session participants are encouraged to wear eyeshades and listen to a curated playlist on headphones.

Sponsors

Usona Institute
Lead SponsorOTHER
The Emmes Company, LLC
CollaboratorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
21 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

* 21 to 65 years old * Able to swallow capsules * If of childbearing potential, agree to practice an effective means of birth control throughout the duration of the study * Have an identified support person and agree to be accompanied home by that person following dosing * Have sustained moderate-severe depression symptoms at Screening and Baseline * Meet DSM-5 criteria for a diagnosis of major depressive disorder and are currently experiencing a major depressive episode of at least a 60-day duration at the time of screening

Exclusion criteria

* Women who are pregnant or who intend to become pregnant during the study or who are currently nursing * Have any of the following cardiovascular conditions: uncontrolled hypertension, coronary artery disease, congenital long QT syndrome, cardiac hypertrophy, cardiac ischemia, congestive heart failure, myocardial infarction, tachycardia, artificial heart valve, a clinically significant screening ECG abnormality, or any other significant cardiovascular condition * Have a history of stroke or Transient Ischemic Attack (TIA) * Have moderate to severe hepatic impairment * Have epilepsy * Have insulin-dependent diabetes * Have a positive urine drug test * Nicotine dependence that would disallow an individual to be nicotine free for the 7-10 hours during the dosing period * Meet DSM-5 criteria for schizophrenia spectrum or other psychotic disorders, including major depressive disorder with psychotic features, or Bipolar I or Bipolar II Disorder * Meet DSM-5 criteria for antisocial personality disorder * Meet DSM-5 criteria for a moderate or severe alcohol or drug use disorder

Design outcomes

Primary

MeasureTime frameDescription
Change in Central Rater Montgomery-Asberg Depression Rating Scale (MADRS) Total Score From Baseline to Post-dose Day 43Baseline; Day 43 post-doseThe MADRS is a clinician-rated scale designed to measure depression severity and to detect changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total score range of 0-60. Higher scores represent a more severe condition. The total (composite) MADRS score is used as the endpoint.

Secondary

MeasureTime frameDescription
Change in Central Rater MADRS Score From Baseline to Post-dose Day 8Baseline; Day 8 post-doseThe MADRS is a clinician-rated scale designed to measure depression severity and to detect changes due to antidepressant treatment. The scale consists of 10 items, each of which is scored from 0 (item not present or normal) to 6 (severe or continuous presence of the symptoms), for a total possible score of 60. Higher scores represent a more severe condition. The total (composite) MADRS score is used as the endpoint.
Change in On-site Rater Administered Sheehan Disability Scale (SDS) Score From Baseline to Post-dose Day 43Baseline; Day 43 post-doseThe SDS consists of three self-rated items designed to measure the extent to which three major domains in the patient's life are impaired by psychiatric symptoms, including depression. The SDS Mean score is calculated as the mean of three items (work/school, social life, family life/home responsibilities), each scored 0 to 10. Mean score range: 0 to 10. Higher scores indicate greater functional impairment.
Sustained Depressive Symptom Response Defined as a ≥ 50% Reduction From Baseline Central Rater MADRS Score at All Post-dose AssessmentsDay 8, 15, 29, and 43 post-doseSustained depressive symptom response defined as ≥50% reduction from Baseline central-rater MADRS total score at all of the following post-dose assessments: Day 8, Day 15, Day 29, and Day 43. Participants who did not meet the criterion at all four timepoints were classified as non-responders. MADRS total score range: 0 to 60; higher scores indicate more severe depression.
Sustained Depressive Symptom Remission Defined as a Central Rater Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score ≤ 10 at All Post-dose AssessmentsDay 8, 15, 29, and 43 post-doseSustained depressive symptom remission defined as a central-rater MADRS total score ≤ 10 at all of the following post-dose assessments: Day 8, Day 15, Day 29, and Day 43. Participants missing a MADRS assessment at any post-dose timepoint were excluded from this analysis. MADRS total score range: 0 to 60; higher scores indicate more severe depression.

Countries

United States

Contacts

STUDY_DIRECTORCharles Raison, MD

Usona Institute

Participant flow

Recruitment details

Participants were recruited at 11 US sites. Individuals were screened by telephone and then in person to confirm eligibility. Of 1,529 individuals who completed prescreening, 347 provided informed consent (enrolled) and 104 were randomized.

Pre-assignment details

Eligible participants completed baseline assessments and preparation sessions. Participants taking antidepressants entered a supervised medication taper. Three participants were discontinued during the preparation phase prior to randomization (1 voluntary withdrawal, 2 withdrawn by investigator decision). Randomization occurred on the day of dosing.

Baseline characteristics

Characteristic
Age, Continuous40.4 years
STANDARD_DEVIATION 10.9
Baseline Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score35.5 units on a scale
STANDARD_DEVIATION 5.7
Baseline Sheehan Disability Scale (SDS) Total Score6.69 units on a scale
STANDARD_DEVIATION 1.99
Ethnicity (NIH/OMB)
Hispanic or Latino
16 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
87 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
3 Participants
Race (NIH/OMB)
More than one race
6 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
2 Participants
Race (NIH/OMB)
White
44 Participants
Region of Enrollment
United States
104 participants
Sex: Female, Male
Female
28 Participants
Sex: Female, Male
Male
25 Participants
Treatment-Resistant Depression Status
No
91 Participants
Treatment-Resistant Depression Status
Yes
6 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 500 / 54
other
Total, other adverse events
43 / 5032 / 54
serious
Total, serious adverse events
0 / 500 / 54

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 23, 2026