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RecruitingPhase 1

The Neurobiological Effect of 5-HT2AR Modulation

NCT03289949 · NeuroPharm2 · Gitte Moos Knudsen

Recruiting
Status
Accepting participants
Phase 1
Phase
200
Target enrolment
1
Study sites
Outside the US

What it is testing

Summary

The investigators wish to investigate neurobiological effects of serotonin 2A receptor modulation in healthy volunteers, contrasting effects of an agonist (psilocybin) and an antagonist (ketanserin). Magnetic resonance imaging (MRI) and positron emission tomography (PET) will be used as neuroimaging tools.

Summary as written by the trial’s own sponsor and published on ClinicalTrials.gov API v2. It is the sponsor’s description, reproduced unedited, not an assessment by this site.

What counts as success

Primary outcome measures

  • Psilocin/ketanserin blood concentrations and 5-HT2A receptor occupancy (i.e., binding potential).

    Measured over Change in Cimbi-36 binding potential from baseline PET to intervention PET 1 and PET 2 scans (same day for psilocybin, and two consecutive days for ketanserin).

  • Effects of psilocybin on Cimbi-36 binding potential at baseline and at one and twelve weeks

    Measured over Change in Cimbi-36 binding potential from baseline to one week post psilocybin (and potentially also at 12 weeks after psilocybin).

  • Effects of psilocybin and ketanserin on brain function assessed with fMRI and PET

    Measured over Changes in functional connectivity (fMRI) from Baseline MR to intervention MR scans for ketanserin (one or three weeks after baseline MR) and psilocybin (one or three weeks after baseline)

  • Effects of psilocybin on UCB-J binding potential at baseline and at one week

    Measured over Change in UCB-J binding potential from baseline to one week post psilocybin.

  • Effects of psilocybin on brain function assessed with fMRI at baseline and one month

    Measured over Change in fMRI measures from baseline to one month post psilocybin

  • Anxiety Outcome Measure 1: Acute psychological effects as assessed using Challenging Experiences Questionnaire (CEQ).

    Measured over Immediately post-intervention.

  • Anxiety Outcome Measure 2: Acute psychological effects as assessed using 5D-Altered States of Consciousness (5D-ASC) scale.

    Measured over Immediately post-intervention.

  • Anxiety Outcome Measure 3: Acute psychological effects as assessed using Extended Subjective Drug Intensity (eSDI) scale.

    Measured over During intervention.

  • Transformative Experiences Outcome Measure 1: Acute psychological effects as assessed using Mystical Type Experiences Questionnaire (MEQ) scale.

    Measured over Immediately post-intervention.

  • Transformative Experiences Outcome Measure 2: Acute psychological effects as assessed using Psychological Insights Questionnaire (PIQ) scale.

    Measured over Immediately post-intervention.

  • Transformative Experiences Outcome Measure 3: Acute psychological effects as assessed using Emotional Breakthrough Questionnaire (EBI) scale.

    Measured over Immediately post-intervention.

  • Persisting Effects Outcome Measure 1: Persisting psychological effects as assessed using Persisting Effects Questionnaire (PEQ) scale.

    Measured over One and three months post-intervention.

A trial succeeds or fails on its primary outcome, declared in advance. Everything else it reports is secondary by definition.

Who can take part

Eligibility, as published

18 Years
Ages
All
Sex
Accepted
Healthy volunteers
Inclusion Criteria: 1\) Healthy individuals above 18 years of age. Exclusion Criteria (For Subprojects 1, 2a, 2b, and 3): 1. Presence of or previous primary psychiatric disease (DSM axis 1 or WHO ICD-10 diagnostic classifications) or in first-degree relatives. 2. Previous or present neurological condition/disease, significant somatic condition/disease or intake of drugs suspected to influence test results. 3. Non-fluent Danish language skills. 4. Vision or hearing impairment. 5. Previous or present learning disability. 6. Pregnancy. 7. Breastfeeding. 8. Contraindications in regard to MRI scanning. 9. Alcohol or drug abuse. 10. Allergy to test drugs. 11. Participation in studies in which participant has received more than 10 mSv of radiation or other significant exposure to radiation. 12. Abnormal ECG or intake of QT prolonging medication. 13. Previous significant side-effects in regard to hallucinogenic drugs. 14. Use of hallucinogenic drugs 6 months previous to inclusion. 15. Blood donation 3 months before and after project participation 16. Body weight under 50 kg. 17. Plasma ferritin levels outside normal range Exclusion Criteria (For Subproject 2c): 1. Presence of or previous primary psychiatric disease (DSM IV axis 1 or WHO ICD-10 diagnostic classifications). 2. Presence of or previous primary psychiatric disease with psychosis symptoms or hypomania (DSM IV axis 1 \[drug/alcohol abuse/dependence, schizophrenia and other psychoses\] or WHO ICD-10 diagnostic classifications \[F10-29, as well as F30-39 with psychotic symptoms, F60\]) in first-degree relatives (parents or siblings). 3. Previous or present neurological condition/disease, significant somatic condition/disease or intake of drugs suspected to influence test results. 4. Non-fluent Danish language skills or pronounced vision or hearing impairment. 5. Previous or present learning disability. 6. Pregnancy. 7. Breastfeeding. 8. Contraindications in regard to MRI scanning. 9. Alcohol or drug abuse. 10. Allergy to test drugs. 11. Abnormal ECG or intake of QT prolonging medication. 12. Previous significant side-effects in regard to hallucinogenic drugs. 13. Previous use of hallucinogenic drugs. 14. Body weight under 45 kg. 15. Ethical concerns regarding the administration of a psychedelic drug.

Where

1 study site

FacilityCityRegionCountry
Neurobiology Research Unit, RigshospitaletCopenhagenDenmark

On the registry

Contact the trial directly

This site does not enrol anyone and is not involved in this trial. To ask about taking part, use the sponsor’s own contact details on the official registry record, which is also where the most current version of everything above lives.

Before you do, the preparation checklist lists what a site will ask you on a first call and what is worth asking them. It is free and collects nothing.

NCT03289949 on ClinicalTrials.gov →

Last updated in the registry 2024-12-16. Registry records change; this page reflects the data build of 2026-08-25.

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Where this trial sits