Adults 25 to 65, any sex, with Perception Disturbance or Visual Suppression. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Psychophysical Descrimination Threshold - No Surround Suppression (NS) Dose 1Primary· 3 hours after dose 1
No surround suppression condition for visual psychophysics tasks, consisting of perceptual judgments (e.g., subject reported which of two visual stimuli presented appeared to have higher contrast). Based on these responses, psychophysical discrimination thresholds are calculated using an adaptive staircase technique and reported in units of percent contrast.
.
Group
Value
95% CI
Psilocybin
.4849
± .11731
Niacin
.499
± .04398
Psychophysical Descrimination Threshold - No Surround Suppression (NS) Dose 2Primary· 3 hours after dose 2
No surround suppression condition for visual psychophysics tasks, consisting of perceptual judgments (e.g., subject reported which of two visual stimuli presented appeared to have higher contrast). Based on these responses, psychophysical discrimination thresholds are calculated using an adaptive staircase technique and reported in units of percent contrast.
.
Orthogonal surround suppression condition for visual psychophysics tasks, consisting of perceptual judgments (e.g., subject reported which of two visual stimuli presented appeared to have higher contrast). Based on these responses, psychophysical discrimination thresholds are calculated using an adaptive staircase technique and reported in units of percent contrast. Orthogonal surround suppression condition (OS).
Orthogonal surround suppression condition for visual psychophysics tasks, consisting of perceptual judgments (e.g., subject reported which of two visual stimuli presented appeared to have higher contrast). Based on these responses, psychophysical discrimination thresholds are calculated using an adaptive staircase technique and reported in units of percent contrast. Orthogonal surround suppression condition (OS).
Parallel surround suppresion condition for visual psychophysics tasks consisting of perceptual judgments (e.g., subject reported which of two visual stimuli presented appeared to have higher contrast). Based on these responses, psychophysical discrimination thresholds are calculated using an adaptive staircase technique and reported in units of percent contrast. Parallel surround suppression condition (PS).
.
Parallel surround suppresion condition for visual psychophysics tasks consisting of perceptual judgments (e.g., subject reported which of two visual stimuli presented appeared to have higher contrast). Based on these responses, psychophysical discrimination thresholds are calculated using an adaptive staircase technique and reported in units of percent contrast. Parallel surround suppression condition (PS).
.
Group
Value
95% CI
Psilocybin
.4195
± .13829
Niacin
.3672
± .06696
Adverse events — posted to ClinicalTrials.gov
Time frame: Week 12.
Reporting threshold: 0%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
The prospective pilot study will address the critical need for more precise characterizations of the acute visual effects of the drug psilocybin by measuring the impact of acute psilocybin intoxication on a perceptual task known as visual surround suppression, compared to an active placebo control.
Publications & conference data
1 peer-reviewed publication reference this trial (live from Europe PMC):
NCT06885996 — Psilocybin-assisted Therapy for Post-Traumatic Stress Disorder in Survivors of Intimate Partner Violence
· Phase 2
· not yet recruiting
NCT07499583 — Psilocybin Assisted Psychotherapy for Treatment Resistant Depression and Co-occurring Substance Use Disorder
· Phase 1, PHASE2
· not yet recruiting
NCT07226232 — Psilocybin Intervention for Veterans Overcoming Treatment-Resistant Depression
· Phase 3
· not yet recruiting
NCT07336238 — Group Retreat Psilocybin Therapy for the Treatment of Anxiety and Depression in Patients With Metastatic Solid Tumors or
· Phase 2
· recruiting
NCT07506395 — Group Psilocybin-Assisted Therapy for Post-Traumatic Stress Disorder
· Phase 1
· not yet recruiting
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Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by University of Minnesota
Last refreshed: 27 June 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT04424225.