Trial Outcomes & Findings for A Study of Psilocybin for Major Depressive Disorder (MDD) (NCT NCT03866174)

Last Updated: 2026-04-22

Results Overview

The 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.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

347 participants

Primary outcome timeframe

Baseline; Day 43 post-dose

Results posted on

2026-04-22

Participant Flow

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.

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 Three participants were discontinued during the preparation phase prior to randomization (1 voluntary withdrawal, 2 withdrawn by investigator decision).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.

Participant milestones

Participant milestones
Measure	Psilocybin Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Overall Study STARTED	51	53
Overall Study COMPLETED	50	42
Overall Study NOT COMPLETED	1	11

Reasons for withdrawal

Reasons for withdrawal
Measure	Psilocybin Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Overall Study Death in family; participant unable to continue in study	1	0
Overall Study 2 participants did not complete Day 43 assessments. 1 participant did not complete follow-up visits.	0	3
Overall Study Withdrawal by Subject	0	6
Overall Study Lost to Follow-up	0	2

Baseline Characteristics

A Study of Psilocybin for Major Depressive Disorder (MDD)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Psilocybin n=51 Participants Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin n=53 Participants Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.	Total n=104 Participants Total of all reporting groups
Age, Continuous	40.4 years STANDARD_DEVIATION 10.9 • n=60 Participants	41.8 years STANDARD_DEVIATION 11.7 • n=56 Participants	41.1 years STANDARD_DEVIATION 11.3 • n=116 Participants
Sex: Female, Male Female	24 Participants n=60 Participants	28 Participants n=56 Participants	52 Participants n=116 Participants
Sex: Female, Male Male	27 Participants n=60 Participants	25 Participants n=56 Participants	52 Participants n=116 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=60 Participants	0 Participants n=56 Participants	0 Participants n=116 Participants
Race (NIH/OMB) Asian	0 Participants n=60 Participants	0 Participants n=56 Participants	0 Participants n=116 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=60 Participants	0 Participants n=56 Participants	0 Participants n=116 Participants
Race (NIH/OMB) Black or African American	3 Participants n=60 Participants	0 Participants n=56 Participants	3 Participants n=116 Participants
Race (NIH/OMB) White	44 Participants n=60 Participants	49 Participants n=56 Participants	93 Participants n=116 Participants
Race (NIH/OMB) More than one race	4 Participants n=60 Participants	2 Participants n=56 Participants	6 Participants n=116 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=60 Participants	2 Participants n=56 Participants	2 Participants n=116 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	4 Participants n=60 Participants	12 Participants n=56 Participants	16 Participants n=116 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	46 Participants n=60 Participants	41 Participants n=56 Participants	87 Participants n=116 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=60 Participants	0 Participants n=56 Participants	1 Participants n=116 Participants
Region of Enrollment United States	51 participants n=60 Participants	53 participants n=56 Participants	104 participants n=116 Participants
Baseline Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score	35.5 units on a scale STANDARD_DEVIATION 5.7 • n=60 Participants	35.0 units on a scale STANDARD_DEVIATION 4.5 • n=56 Participants	35.2 units on a scale STANDARD_DEVIATION 5.1 • n=116 Participants
Treatment-Resistant Depression Status Yes	7 Participants n=60 Participants	6 Participants n=56 Participants	13 Participants n=116 Participants
Treatment-Resistant Depression Status No	44 Participants n=60 Participants	47 Participants n=56 Participants	91 Participants n=116 Participants
Baseline Sheehan Disability Scale (SDS) Total Score	6.69 units on a scale STANDARD_DEVIATION 1.99 • n=60 Participants	7.14 units on a scale STANDARD_DEVIATION 1.61 • n=56 Participants	6.92 units on a scale STANDARD_DEVIATION 1.81 • n=116 Participants

PRIMARY outcome

Timeframe: Baseline; Day 43 post-dose

Population: All 104 randomized participants analyzed by randomized treatment assignment using a mixed-effect model for repeated measures under missing-at-random assumption. Number analyzed reflects the intent-to-treat analysis population, not observed cases at each timepoint.

Outcome measures

Outcome measures
Measure	Psilocybin n=51 Participants Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin n=53 Participants Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Change in Central Rater Montgomery-Asberg Depression Rating Scale (MADRS) Total Score From Baseline to Post-dose Day 43	-19.1 units on a scale Standard Error 1.8	-6.8 units on a scale Standard Error 1.9

SECONDARY outcome

Timeframe: Baseline; Day 8 post-dose

The 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.

Outcome measures

Outcome measures
Measure	Psilocybin n=51 Participants Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin n=53 Participants Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Change in Central Rater MADRS Score From Baseline to Post-dose Day 8	-17.8 units on a scale Standard Error 1.6	-5.8 units on a scale Standard Error 1.6

SECONDARY outcome

Timeframe: Baseline; Day 43 post-dose

The 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.

Outcome measures

Outcome measures
Measure	Psilocybin n=51 Participants Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin n=53 Participants Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Change in On-site Rater Administered Sheehan Disability Scale (SDS) Score From Baseline to Post-dose Day 43	-4.07 units on a scale Standard Error 0.41	-1.76 units on a scale Standard Error 0.43

SECONDARY outcome

Timeframe: Day 8, 15, 29, and 43 post-dose

Population: All randomized participants with observed central-rater MADRS assessments at Baseline, Day 8, Day 15, Day 29, and Day 43. Participants missing a MADRS assessment at any post-dose timepoint were excluded from this analysis.

Sustained 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.

Outcome measures

Outcome measures
Measure	Psilocybin n=48 Participants Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin n=44 Participants Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Sustained Depressive Symptom Response Defined as a ≥ 50% Reduction From Baseline Central Rater MADRS Score at All Post-dose Assessments Sustained response	20 Participants	5 Participants
Sustained Depressive Symptom Response Defined as a ≥ 50% Reduction From Baseline Central Rater MADRS Score at All Post-dose Assessments No sustained response	28 Participants	39 Participants

SECONDARY outcome

Timeframe: Day 8, 15, 29, and 43 post-dose

Sustained 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.

Outcome measures

Outcome measures
Measure	Psilocybin n=48 Participants Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin n=44 Participants Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Sustained Depressive Symptom Remission Defined as a Central Rater Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score ≤ 10 at All Post-dose Assessments Sustained remission	12 Participants	4 Participants
Sustained Depressive Symptom Remission Defined as a Central Rater Montgomery-Åsberg Depression Rating Scale (MADRS) Total Score ≤ 10 at All Post-dose Assessments No sustained remission	36 Participants	40 Participants

Adverse Events

Psilocybin

Serious events: 0 serious events

Other events: 43 other events

Deaths: 0 deaths

Niacin

Serious events: 0 serious events

Other events: 32 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Psilocybin n=50 participants at risk Single oral dose of 25 mg psilocybin administered as a capsule in a supervised clinical setting in conjunction with the Set and Setting (SaS) protocol. Participants were supervised by two trained facilitators throughout the dosing session and assessed for readiness prior to release.	Niacin n=54 participants at risk Single oral dose of 100 mg niacin administered as a capsule, used as an active comparator to maintain blinding through flushing effects. Administered in conjunction with the identical Set and Setting (SaS) protocol and supervised conditions as the psilocybin group.
Nervous system disorders Headache	66.0% 33/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	25.9% 14/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Gastrointestinal disorders Nausea	48.0% 24/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	5.6% 3/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Psychiatric disorders Illusion	46.0% 23/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	5.6% 3/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Nervous system disorders Dizziness	12.0% 6/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	3.7% 2/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Vascular disorders Flushing	2.0% 1/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	11.1% 6/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
General disorders Fatigue	10.0% 5/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	1.9% 1/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Psychiatric disorders Anxiety	10.0% 5/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	5.6% 3/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Nervous system disorders Migraine	8.0% 4/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	3.7% 2/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Psychiatric disorders Depression	8.0% 4/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	3.7% 2/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Gastrointestinal disorders Vomiting	6.0% 3/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	0.00% 0/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Infections and infestations Urinary tract infection	6.0% 3/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	3.7% 2/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Psychiatric disorders Insomnia	6.0% 3/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	1.9% 1/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
Nervous system disorders Paraesthesia	2.0% 1/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	7.4% 4/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.
General disorders Antidepressant discontinuation syndrome	4.0% 2/50 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.	5.6% 3/54 • The maximum study duration was 12 weeks (enrollment through Day 43 post-dose). Adverse events were collected at all study visits from the time of signed informed consent through the end-of-study visit (Day 43). All randomized participants who received the study intervention, analyzed by actual treatment received. One participant randomized to psilocybin received niacin. Adverse events (AEs) were graded for severity, seriousness, and relationship to study product by site principal investigator. Reported events are treatment emergent AEs, defined as any AE not present prior to treatment or any event already present that worsened in intensity or frequency following study treatment.

Additional Information

Sofiya Hupalo

Usona Institute

Phone: 608-210-5955

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee Per Protocol Section 13.17 (Publication Policy), principal investigators are required to submit all manuscripts or abstracts to the Sponsor prior to submission for publication or presentation. The Sponsor may review to protect proprietary information and provide comments. No specific embargo period is defined. All data analysis must be performed on the official Sponsor database with the analysis plan agreed upon with the Sponsor statistician.
Publication restrictions are in place

Restriction type: OTHER