The Acute Effects of Psilocybin on Cognition, Memory, and Brain Function

NCT07079852 | Not Yet Recruiting Phase 1 FDA Drug

• 1 other identifier: mindflux
• Study Type: interventional
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

This study will test the effects of psilocybin on memory and cognition in healthy participants using computerized tasks and magnetic resonance imaging (MRI).

Conditions

Healthy

Keywords

psilocybin; memory; cognition; psychedelics; fMRI

Outcome Measures

Primary Outcomes (2)

• Memory accuracy from performance on a recognition memory test

  Participants will be presented with a series of pictures, and their recognition memory for these pictures will be tested by presenting pictures that they previous saw (targets) intermixed with new pictures (lures). Their task will be to respond whether a picture is "old" or "new." Hit rate = p("old"\|target), False alarm rate = p("old"\|lure). Memory accuracy = hit rate - false alarm rate

  8 weeks

• Neural correlates of memory as measured from fMRI

  Participants will be scanned with fMRI to measure brain responses associated with memory.

  8 weeks

Study Arms (2)

placebo

PLACEBO COMPARATOR

Capsule containing microcrystalline cellulose

Drug: Placebo

psilocybin

EXPERIMENTAL

Capsule containing 15 mg of psilocybin

Drug: Psilocybin 15mg

Interventions

Placebo DRUG

This is an inactive control condition.

placebo

Psilocybin 15mg DRUG

This is a moderate psychoactive dose.

psilocybin

Eligibility Criteria

• Age: 21 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• to 45-years-old.
• lifetime psychedelic uses.
• English as a first language.
• High school education (or equivalent)
• Psychiatrically healthy (as assessed by the SCID-5).
• Medically healthy (as assessed by a physical examination and ECG).
• Willingness to attend all study sessions and complete all procedures.
• BMI between 19 and 30.

You may not qualify if:

• Current or past diagnosis of psychiatric disorders except panic attacks, depressive disorder, or anxiety, or disorder from ≥1 year prior.
• Current or past medical conditions that might interfere with study participation or be contraindicated for psilocybin administration (e.g., hypertension, history of stroke, cardiovascular disease, etc.)
• Current daily medications except birth control (females).
• Pregnant, nursing, or planning to become pregnant (assessed with urine pregnancy test).
• Ingestion of a psychedelic \<2 months prior to an experimental session (with the exception of psilocybin administered in the context of the current study's repeated measures design).
• History of serious adverse event with a psychedelic and/or self-reported hypersensitivity to psychedelics.
• Inability to abstain from alcohol 48 hours prior to an experimental session.
• Use of other psychoactive drugs (other than caffeine or nicotine) 1 week prior to an experimental session.
• Positive urine drug screening for drugs of abuse during experimental sessions.
• Self-reported ferrous metal, metallic implants, or implanted medical devices that would preclude participation in MRI procedures, including but not limited to cochlear implants, implanted brain stimulators, and aneurysm clips.
• Self-reported past penetrating brain injury or any head injury resulting in a loss of consciousness for 30 minutes or more or post-concussive symptoms for more than seven days following a head injury.
• Self-reported claustrophobia (prohibiting MRI acquisition).
• Any other factors such as unstable housing or life-threatening circumstances, erratic behavior, etc. that are judged by the investigators to be a significant barrier to participation in the study protocol and/or to establishing rapport necessary for safe administration of psilocybin.
• Participant unwillingness to not ingest or use additional serotonergic psychedelics outside the context of study procedures for the duration of the study.
• Resting blood pressure \>140/90 mm hg at study entry.

Sponsors & Collaborators

• Manoj Doss: lead

Study Sites (1)

The University of Texas at Austin Dell Medical School

Austin, Texas, 78712, United States

Location

Related Publications (2)

• Doss MK, Mallaroni P, Mason NL, Ramaekers JG. Psilocybin and 2C-B at Encoding Distort Episodic Familiarity. Biol Psychiatry Cogn Neurosci Neuroimaging. 2024 Oct;9(10):1048-1057. doi: 10.1016/j.bpsc.2024.06.008. Epub 2024 Jun 26.

  PMID: 38942147 BACKGROUND

• Doss MK, Samaha J, Barrett FS, Griffiths RR, de Wit H, Gallo DA, Koen JD. Unique effects of sedatives, dissociatives, psychedelics, stimulants, and cannabinoids on episodic memory: A review and reanalysis of acute drug effects on recollection, familiarity, and metamemory. Psychol Rev. 2024 Mar;131(2):523-562. doi: 10.1037/rev0000455. Epub 2023 Dec 14.

  PMID: 38095937 BACKGROUND

MeSH Terms

Interventions

Psilocybin

Intervention Hierarchy (Ancestors)

Indole Alkaloids; Alkaloids; Heterocyclic Compounds; Indoles; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Tryptamines; Indolizidines; Indolizines

Central Study Contacts

Manoj Doss, PhD

CONTACT

512-495-5856; manoj.doss@austin.utexas.edu

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Double-blind, placebo-controlled, crossover masking
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Assistant Professor

Model Details: All participants will receive both interventions in counterbalanced order.

Study Record Dates

• First Submitted: July 10, 2025
• First Posted: July 23, 2025
• Study Start: September 1, 2025
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: July 23, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will share
• Time Frame: Data will be available following publication of the primary findings.
• Access Criteria: Anyone will be able to access the de-identified behavioral and fMRI data from Open Science Framework and OpenNeuro.

Locations

US (1)