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

NCT ID: NCT07079852

Last Updated: 2025-07-23

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 48 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-30
• Study Completion Date: 2027-08-31

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).

Detailed Description

In a double-blind, placebo-controlled, repeated measures design in healthy participants, this study will test the effects of psilocybin on memory and cognition in healthy individuals using computerized tasks and magnetic resonance imaging (MRI). A better understanding of the basic neurocognitive effects of psilocybin may allow for minimizing potential harms and maximizing potential benefits of psilocybin therapy.

Conditions

Healthy

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: QUADRUPLE

Study Groups

placebo

Capsule containing microcrystalline cellulose

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: DRUG

This is an inactive control condition.

psilocybin

Capsule containing 15 mg of psilocybin

Group Type: EXPERIMENTAL

Psilocybin 15mg

Intervention Type: DRUG

This is a moderate psychoactive dose.

Interventions

Placebo

This is an inactive control condition.

Intervention Type: DRUG

Psilocybin 15mg

This is a moderate psychoactive dose.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• 21 to 45-years-old.
• 3-30 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.

Exclusion Criteria

• 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.
• Lifetime history of cardiomyopathy, stroke, heart disease, heart attack, tachycardia, elongated QT-interval corrected by Friderichia (> 450ms for men and > 470ms for women); clinically significant cardiac arrhythmia within 1 year of study entry; and/or abnormal electrocardiogram on study entry.
• Left-handedness (given that functional lateralizations may differ from those of right-handed individuals).

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Manoj Doss

OTHER

Sponsor Role: lead

Responsible Party

Manoj Doss

Assistant Professor

Responsibility Role: SPONSOR_INVESTIGATOR

Locations

The University of Texas at Austin Dell Medical School

Austin, Texas, United States

Countries

United States

Central Contacts

Manoj Doss, PhD

Role: CONTACT

manoj.doss@austin.utexas.edu

512-495-5856

Facility Contacts

Manoj Doss, PhD

Role: primary

manoj.doss@austin.utexas.edu

512-495-5856

References

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.

Reference Type: BACKGROUND

PMID: 38942147 (View on PubMed)

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.

Reference Type: BACKGROUND

PMID: 38095937 (View on PubMed)

Other Identifiers

mindflux

Identifier Type: -

Identifier Source: org_study_id