Basic SciencePhase 1NeuroPharm2NCT03289949
The Neurobiological Effect of 5-HT2AR Modulation
A Phase 1 study testing Psilocybine and Ketanserin in people with Basic Science, run by Gitte Moos Knudsen at 1 site in Denmark.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Basic Science
- What is being tested?
- Psilocybine and Ketanserin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 200 participants
- Where
- 1 siteDenmark
- Study dates
- 3 Mar 2017to 1 Jun 2030
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 1) Healthy individuals above 18 years of age.
Who cannot join
- Presence of or previous primary psychiatric disease (DSM axis 1 or WHO ICD-10 diagnostic classifications) or in first-degree relatives.
- Previous or present neurological condition/disease, significant somatic condition/disease or intake of drugs suspected to influence test results.
- Non-fluent Danish language skills.
- Vision or hearing impairment.
- Previous or present learning disability.
- Pregnancy.
Show all 32Show fewer
- Breastfeeding.
- Contraindications in regard to MRI scanning.
- Alcohol or drug abuse.
- Allergy to test drugs.
- Participation in studies in which participant has received more than 10 mSv of radiation or other significant exposure to radiation.
- Abnormal ECG or intake of QT prolonging medication.
- Previous significant side-effects in regard to hallucinogenic drugs.
- Use of hallucinogenic drugs 6 months previous to inclusion.
- Blood donation 3 months before and after project participation
- Body weight under 50 kg.
- Plasma ferritin levels outside normal range
- Presence of or previous primary psychiatric disease (DSM IV axis 1 or WHO ICD-10 diagnostic classifications).
- 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).
- Previous or present neurological condition/disease, significant somatic condition/disease or intake of drugs suspected to influence test results.
- Non-fluent Danish language skills or pronounced vision or hearing impairment.
- Previous or present learning disability.
- Pregnancy.
- Breastfeeding.
- Contraindications in regard to MRI scanning.
- Alcohol or drug abuse.
- Allergy to test drugs.
- Abnormal ECG or intake of QT prolonging medication.
- Previous significant side-effects in regard to hallucinogenic drugs.
- Previous use of hallucinogenic drugs.
- Body weight under 45 kg.
- Ethical concerns regarding the administration of a psychedelic drug.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Denmark1 site, 1 recruiting
- Recruiting
Neurobiology Research Unit, Rigshospitalet
Copenhagen, 2100
Gitte M Knudsen, Professor
Patrick M Fisher, PhD, +4535456714, patrick.fisher@nru.dk
About this study
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.
Read the detailed description
This project applies an experimental medicine strategy coupled with human functional and molecular neuroimaging to elucidate the effects of 5-HT2A receptor (5-HT2AR) modulation on brain function and mood in healthy individuals. We compare psilocybin (5-HT2AR agonist) and ketanserin (5-HT2AR antagonist) effects on brain function to identify neural mechanisms mediating the clinical effects of psilocybin and, more broadly, to establish this comparative strategy as a pathway for delineating pharmacological effects on the brain in humans.
- Conditions
- Basic Science
- Being tested
- Psilocybine, Ketanserin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PsilocybineDrug
Also called Psilocybin
Oral dose of psilocybine.
KetanserinDrug
Also called Ketensin
Oral dose of ketanserin.
| Study group | Role | What they receive |
|---|---|---|
| Project 1: Occupancy of psilocybin/ketanserin | Other | After baseline MRI \& 5-HT2AR PET-imaging, participants will be allocated to undergo either one oral dose of psilocybine or one oral dose of ketanserin. After drug administration, participants will undergo two CIMBI-36 PET scans. Receives: Drug: Psilocybine; Drug: Ketanserin |
| Project 2: Long term effects of psilocybin | Other | After baseline MRI \& CIMBI-36 PET-imaging, participants will receive one dose of oral psilocybine intervention. One and 12 weeks after dosing, participants will undergo post-intervention PET-scan.
Subproject B: After baseline MRI \& UCB-J PET-imaging, participants will receive one dose of oral psilocybine intervention. One week after dosing, participants will undergo post-intervention UCB-J PET-scan.
Subproject C: After baseline MR imaging, participants will receive one dose of oral psilocybine (25 mg) or placebo. One month after dosing, participants will undergo a post-intervention MRI scan. Receives: Drug: Psilocybine |
| Project 3: Functional connectivity | Other | After baseline MRI scanning and CIMBI-36 PET, participants will undergo one psilocybine-intervention fMRI scan and one ketanserin-intervention fMRI scan. If P2 shows there are long term effects of psilocybine on 5-HT2AR levels, psilocybine will be fixed as the second intervention. If not, interventions will be randomized. Receives: Drug: Psilocybine; Drug: Ketanserin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Psilocin/ketanserin blood concentrations and 5-HT2A receptor occupancy (i.e., binding potential).
The investigators aim to model relations psilocin/ketanserin blood drug concentrations and receptor occupancy, using C11-Cimbi-36 PET imaging.
Measured: 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
Cimbi-36 PET scan binding potential at baseline and at one-week post psilocybin, and potentially also at 12 weeks post psilocybin.
Measured: 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
Correlations between blood levels of ketanserin and psilocin and the estimated associated receptor occupancy with functional MRI neuroimaging data, including resting state networks. Changes in synaptic density will be assessed with 11C-UCB-J PET scans before and 1 week after psilocybin intervention.
Measured: 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
Project 2, Subproject B. UCB-J PET scan binding potential at baseline and at one-week post psilocybin.
Measured: 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
Project 2, Subproject C. Resting-state and task-based fMRI measures at baseline and one month post psilocybin.
Measured: 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).
Differences in CEQ scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely; More than ever). Higher scores thus reflect a more challenging experience. Project 2, Subproject C. PsiloZonic.
Measured: Immediately post-intervention.
Anxiety Outcome Measure 2: Acute psychological effects as assessed using 5D-Altered States of Consciousness (5D-ASC) scale.
Differences in 5D-ASC anxiety scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Visual analogue scale (VAS) scale ranging from 0 (No, not more than usually) to 100 (Yes, much more than usually). Higher scores on dimension anxiety thus reflect more anxiety. Project 2, Subproject C. PsiloZonic.
Measured: Immediately post-intervention.
Anxiety Outcome Measure 3: Acute psychological effects as assessed using Extended Subjective Drug Intensity (eSDI) scale.
Differences in eSDI anxiety scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 10 (Very much). Higher scores on item anxiety thus reflect more anxiety. Project 2, Subproject C. PsiloZonic.
Measured: During intervention.
Transformative Experiences Outcome Measure 1: Acute psychological effects as assessed using Mystical Type Experiences Questionnaire (MEQ) scale.
Differences in MEQ scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely). Higher scores thus reflect a more profound mystical type experience. Project 2, Subproject C. PsiloZonic.
Measured: Immediately post-intervention.
Transformative Experiences Outcome Measure 2: Acute psychological effects as assessed using Psychological Insights Questionnaire (PIQ) scale.
Differences in PIQ scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely). Higher scores thus reflect more psychological insight. Project 2, Subproject C. PsiloZonic.
Measured: Immediately post-intervention.
Transformative Experiences Outcome Measure 3: Acute psychological effects as assessed using Emotional Breakthrough Questionnaire (EBI) scale.
Differences in EBI scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Visual analogue scale (VAS) scale ranging from 0 (No, not more than usually) to 100 (Yes, much more than usually). Higher scores thus reflect more emotional breakthrough. Project 2, Subproject C. PsiloZonic.
Measured: Immediately post-intervention.
Persisting Effects Outcome Measure 1: Persisting psychological effects as assessed using Persisting Effects Questionnaire (PEQ) scale.
Differences in PEQ scores will be assessed between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely). Higher scores thus reflect more persisting effects. Project 2, Subproject C. PsiloZonic.
Measured: One and three months post-intervention.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Sep 2017
- Study start3 Mar 2017
- Primary completion1 Jun 2030 (estimated)
- Study completion1 Jun 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Basic ScienceStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Gitte Moos Knudsen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Gitte Moos Knudsen, Copenhagen University Hospital, Rigshospitalet
- Investigators
- Gitte M Knudsen, Professor, Study chair, Neurobiology Research Unit, Rigshospitalet
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03289949
- Sponsor's protocol ID
- H-16026898
- Acronym
- NeuroPharm2
- Status last verified
- Dec 2024
- First submitted
- 14 Sep 2017
- Last updated
- 16 Dec 2024
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Via database of Center for Integrated Molecular Brain Imaging (Knudsen et al 2016, NeuroImage) data will be available for neuroscience research community contingent on approval by scientific board.
Publications
Johansen A, Plaven-Sigray P, Madsen MK, Sondergaard A, Messel C, Geisler M, Nasser A, McCulloch DE, Beliveau V, Vassilieva A, Lund A, Lehel S, Ozenne B, Stenbaek DS, Fisher PM, Svarer C, Knudsen GM. Psilocybin's effect on human brain synaptic plasticity. Transl Psychiatry. 2026 Jul 15. doi: 10.1038/s41398-026-04285-y. Online ahead of print.
PubMed 42457666Brendstrup-Brix K, Ozenne B, Fisher PM, Stenbaek DS, Petersen AS, Armand S, McCulloch DE, Marstrand-Joergensen MR, Ulv Larsen SM, Johansen A, Jensen RH, Knudsen GM, Madsen MK. Effects of psilocybin on sleep quality and brain microstructure in chronic cluster headache. J Psychopharmacol. 2026 May 29:2698811261449380. doi: 10.1177/02698811261449380. Online ahead of print.
PubMed 42212900
Study at a glance
From the registry record, last updated by the sponsor on 16 Dec 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Neurobiological Effect of 5-HT2AR Modulation
- ClinicalTrials.gov ID
- NCT03289949
- Acronym / sponsor ID
- NeuroPharm2 / H-16026898
- Conditions
- Basic Science
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Gitte Moos KnudsenUniversity, hospital or other
- Study start
- 3 Mar 2017 (actual)
- Primary completion
- 1 Jun 2030 (estimated)
- Study completion
- 1 Jun 2030 (estimated)
- First posted
- 21 Sep 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This project applies an experimental medicine strategy coupled with human functional and molecular neuroimaging to elucidate the effects of 5-HT2A receptor (5-HT2AR) modulation on brain function and mood in healthy individuals. We compare psilocybin (5-HT2AR agonist) and ketanserin (5-HT2AR antagonist) effects on brain function to identify neural mechanisms mediating the clinical effects of psilocybin and, more broadly, to establish this comparative strategy as a pathway for delineating pharmacological effects on the brain in humans.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- Single blind (participant)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Project 1: Occupancy of psilocybin/ketanserin | Other | Drug: Psilocybine, Drug: KetanserinAfter baseline MRI \& 5-HT2AR PET-imaging, participants will be allocated to undergo either one oral dose of psilocybine or one oral dose of ketanserin. After drug administration, participants will undergo two CIMBI-36 PET scans. |
| Project 2: Long term effects of psilocybin | Other | Drug: PsilocybineAfter baseline MRI \& CIMBI-36 PET-imaging, participants will receive one dose of oral psilocybine intervention. One and 12 weeks after dosing, participants will undergo post-intervention PET-scan. Subproject B: After baseline MRI \& UCB-J PET-imaging, participants will receive one dose of oral psilocybine intervention. One week after dosing, participants will undergo post-intervention UCB-J PET-scan. Subproject C: After baseline MR imaging, participants will receive one dose of oral psilocybine (25 mg) or placebo. One month after dosing, participants will undergo a post-intervention MRI scan. |
| Project 3: Functional connectivity | Other | Drug: Psilocybine, Drug: KetanserinAfter baseline MRI scanning and CIMBI-36 PET, participants will undergo one psilocybine-intervention fMRI scan and one ketanserin-intervention fMRI scan. If P2 shows there are long term effects of psilocybine on 5-HT2AR levels, psilocybine will be fixed as the second intervention. If not, interventions will be randomized. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- 1) Healthy individuals above 18 years of age.
Key exclusion criteria (32 listed)
- Presence of or previous primary psychiatric disease (DSM axis 1 or WHO ICD-10 diagnostic classifications) or in first-degree relatives.
- Previous or present neurological condition/disease, significant somatic condition/disease or intake of drugs suspected to influence test results.
- Non-fluent Danish language skills.
- Vision or hearing impairment.
- Previous or present learning disability.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PsilocybineAlso: PsilocybinOral dose of psilocybine. | Drug | Project 1: Occupancy of psilocybin/ketanserin, Project 2: Long term effects of psilocybin, Project 3: Functional connectivity |
| KetanserinAlso: KetensinOral dose of ketanserin. | Drug | Project 1: Occupancy of psilocybin/ketanserin, Project 3: Functional connectivity |
Primary outcome
Psilocin/ketanserin blood concentrations and 5-HT2A receptor occupancy (i.e., binding potential).
Time frame: 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).
The investigators aim to model relations psilocin/ketanserin blood drug concentrations and receptor occupancy, using C11-Cimbi-36 PET imaging.
Effects of psilocybin on Cimbi-36 binding potential at baseline and at one and twelve weeks
Time frame: Change in Cimbi-36 binding potential from baseline to one week post psilocybin (and potentially also at 12 weeks after psilocybin).
Cimbi-36 PET scan binding potential at baseline and at one-week post psilocybin, and potentially also at 12 weeks post psilocybin.
Effects of psilocybin and ketanserin on brain function assessed with fMRI and PET
Time frame: 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)
Correlations between blood levels of ketanserin and psilocin and the estimated associated receptor occupancy with functional MRI neuroimaging data, including resting state networks. Changes in synaptic density will be assessed with 11C-UCB-J PET scans before and 1 week after psilocybin intervention.
Effects of psilocybin on UCB-J binding potential at baseline and at one week
Time frame: Change in UCB-J binding potential from baseline to one week post psilocybin.
Project 2, Subproject B. UCB-J PET scan binding potential at baseline and at one-week post psilocybin.
Effects of psilocybin on brain function assessed with fMRI at baseline and one month
Time frame: Change in fMRI measures from baseline to one month post psilocybin
Project 2, Subproject C. Resting-state and task-based fMRI measures at baseline and one month post psilocybin.
Anxiety Outcome Measure 1: Acute psychological effects as assessed using Challenging Experiences Questionnaire (CEQ).
Time frame: Immediately post-intervention.
Differences in CEQ scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely; More than ever). Higher scores thus reflect a more challenging experience. Project 2, Subproject C. PsiloZonic.
Anxiety Outcome Measure 2: Acute psychological effects as assessed using 5D-Altered States of Consciousness (5D-ASC) scale.
Time frame: Immediately post-intervention.
Differences in 5D-ASC anxiety scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Visual analogue scale (VAS) scale ranging from 0 (No, not more than usually) to 100 (Yes, much more than usually). Higher scores on dimension anxiety thus reflect more anxiety. Project 2, Subproject C. PsiloZonic.
Anxiety Outcome Measure 3: Acute psychological effects as assessed using Extended Subjective Drug Intensity (eSDI) scale.
Time frame: During intervention.
Differences in eSDI anxiety scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 10 (Very much). Higher scores on item anxiety thus reflect more anxiety. Project 2, Subproject C. PsiloZonic.
Transformative Experiences Outcome Measure 1: Acute psychological effects as assessed using Mystical Type Experiences Questionnaire (MEQ) scale.
Time frame: Immediately post-intervention.
Differences in MEQ scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely). Higher scores thus reflect a more profound mystical type experience. Project 2, Subproject C. PsiloZonic.
Transformative Experiences Outcome Measure 2: Acute psychological effects as assessed using Psychological Insights Questionnaire (PIQ) scale.
Time frame: Immediately post-intervention.
Differences in PIQ scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely). Higher scores thus reflect more psychological insight. Project 2, Subproject C. PsiloZonic.
Transformative Experiences Outcome Measure 3: Acute psychological effects as assessed using Emotional Breakthrough Questionnaire (EBI) scale.
Time frame: Immediately post-intervention.
Differences in EBI scores between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Visual analogue scale (VAS) scale ranging from 0 (No, not more than usually) to 100 (Yes, much more than usually). Higher scores thus reflect more emotional breakthrough. Project 2, Subproject C. PsiloZonic.
Persisting Effects Outcome Measure 1: Persisting psychological effects as assessed using Persisting Effects Questionnaire (PEQ) scale.
Time frame: One and three months post-intervention.
Differences in PEQ scores will be assessed between groups (psilocybin with music compared to psilocybin without music). Effects are measured on a Likert-scale ranging from 0 (Not all all) to 5 (Extremely). Higher scores thus reflect more persisting effects. Project 2, Subproject C. PsiloZonic.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Dec 2024.
- Derived from this study: PubMed 42457666Johansen A, Plaven-Sigray P, Madsen MK, Sondergaard A, Messel C, Geisler M, Nasser A, McCulloch DE, Beliveau V, Vassilieva A, Lund A, Lehel S, Ozenne B, Stenbaek DS, Fisher PM, Svarer C, Knudsen GM. Psilocybin's effect on human brain synaptic plasticity. Transl Psychiatry. 2026 Jul 15. doi: 10.1038/s41398-026-04285-y. Online ahead of print.
- Derived from this study: PubMed 42212900Brendstrup-Brix K, Ozenne B, Fisher PM, Stenbaek DS, Petersen AS, Armand S, McCulloch DE, Marstrand-Joergensen MR, Ulv Larsen SM, Johansen A, Jensen RH, Knudsen GM, Madsen MK. Effects of psilocybin on sleep quality and brain microstructure in chronic cluster headache. J Psychopharmacol. 2026 May 29:2698811261449380. doi: 10.1177/02698811261449380. Online ahead of print.
- Individual participant dataSharing planned: Yes. Via database of Center for Integrated Molecular Brain Imaging (Knudsen et al 2016, NeuroImage) data will be available for neuroscience research community contingent on approval by scientific board.
Related trials for Basic Science
Not yet recruitingPhase 1
Evaluation of the Bioequivalence of RAY1225 Injection in Healthy Participants
Basic Science
Active, not recruitingEarly Phase 1
LSD Occupancy of the Serotonin 2A Receptor in the Human Brain
Basic Science
Not yet recruiting
Transcranial Ultrasonic Neuromodulation of Primary Visual Cortex and Primary Auditory Cortex in Humans
Healthy Volunteers, no Condition, Basic Science
Enrolling by invitation
Probing the Role of Feature Dimension Maps in Visual Cognition: Impact of Task Demands and Spatial Attention (Expt 2.2)
Basic Science: Visual Attention in Healthy Participants, Basic Science: Neural Representations of Location
Recruiting
Neural Basis of Sensory Learning: Brain Regions
Basic Science
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Gitte M Knudsen, Professor study chair
Neurobiology Research Unit, Rigshospitalet
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Psilocybine and Ketanserin in people with Basic Science, run by Gitte Moos Knudsen at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 32 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 16 Dec 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Gitte M Knudsen, Professor (+45 35456720, gmk@nru.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Psilocin/ketanserin blood concentrations and 5-HT2A receptor occupancy (i.e., binding potential). (time frame: 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).). The study lists 12 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03289949, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Dec 2024; AzTrials last refreshed its copy on 1 Nov 2026.