HealthyPhase 1NCT06081179
Does Serotonin System Stimulation Increase Pro-social Behavior? - A Comparative Pharmacological Neuroscientific Study in Healthy Humans
A Phase 1 study testing Psilocybin, 3,4 Methylenedioxymethamphetamine and Methylphenidate in people with Healthy, run by University of Zurich at 1 site in Switzerland.
Trial summary
The study looks into whether administering psychedelic substances that stimulate the serotonin system influences pro-social behavior when compared to administering substances that stimulate the dopamine system in healthy individuals. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Psilocybin, 3,4 Methylenedioxymethamphetamine and Methylphenidate
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 122 participants
- Where
- 1 siteSwitzerland
- Study dates
- 24 Oct 2023to 22 Sep 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy male or female at the age of 18-40
- Willing and capable to give informed consent for study participation as documented by signature (Informed Consent Form) after the nature of the study has been thoroughly explained
- Willing to refrain from drinking alcohol the day before testing session, from drinking alcohol and caffeinated drinks at the testing days and from consuming psychoactive substances two weeks before the first investigation visit and for the duration of the study
- Willing to abstain from using drugs that may interfere with the effects of the study medications including sleeping aids, cough medications, beta-blocker or other substances with potentially relevant psychoactive and cardiovascular effects.
- Able and willing to comply with all study requirements
- Good physical health with no unstable medical conditions, as determined by medical history, physical examination, routine blood labs, electrocardiogram, urine analysis, and urine toxicology
Show all 9Show fewer
- Women of childbearing potential (as defined by: 'the age of carrying or giving birth to a child', normally between 14-45 years of age, not in menopause, last menstrual period (LMP) less than 12 months, no removal of ovaries or uterus, no ligature of Fallopian tubes') must be using an effective, established method of contraception for the entire study duration, such as oral, injectable, or implantable contraceptives, or intrauterine contraceptive devices. Note: female participants who are surgically sterilized/hysterectomized or post-menopausal for longer than 2 years are not considered as being of childbearing potential
- Willing not to drive a traffic vehicle or to operate machines within 48h following substance administration
- Have a family member or friend who can pick them up after the substance administration sessions (driving is forbidden at drug treatment days)
Who cannot join
- Poor knowledge of the German language
- Previous significant adverse response to a hallucinogenic drug (incl. psilocybin), MDMA, or methylphenidate
- Allergy or hypersensitivity to previous use of MDMA, psilocybin, or methylphenidate
- Lifetime history of hallucinogen (incl. psilocybin), MDMA, or methylphenidate use on more than 10 occasions
- Personal and family history of major psychiatric disease (e.g., schizophrenia, schizoaffective disorder, psychosis, major depression, bipolar disorder, psychotic disorder, substance addiction/abuse other than caffeine and nicotine) as defined in the DSM-V (1st and 2nd degree relatives)
- History of suicidal behavior
Show all 21Show fewer
- Inability to follow the procedures of the study, e.g., due to language problems, psychological disorders, dementia, etc. of the participant
- Attention-Deficit/Hyperactivity-Disorder (ADHD)
- Any current major medical condition (e.g., neurologic, cardiovascular, metabolic, infectious disease) or any unstable illness as determined by medical history or laboratory tests
- Uncorrected hypo-or hyperthyroidism
- Uncorrected hypo-and hypertension
- Epilepsy
- Abnormal electrocardiogram
- BMI <17 or >35
- Personal history of head trauma, brain/cardiac surgery, fainting, or electroconvulsive therapy
- Personal and family history of seizure disorder and strokes (1st and 2nd degree relatives)
- Participation in another study where pharmaceutical compounds are given within the 30 days preceding and during the present study
- Current psychopharmacological treatment or medication that affects brain function
- Use of medications that are contraindicated or otherwise interfere with the effects of the study medications (monoamine oxidase inhibitors, antidepressants, sedatives etc.)
- Women who are pregnant or breast feeding, or have the intention to become pregnant during the study (for safety reasons, a urine pregnancy test will be done at the screening visit and before the substance administration)
- Enrollment of the investigator, his/her family members, employees, and other dependent persons
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
Psychiatrische Universitätsklinik Zürich
Zurich, Canton of Zurich, 8032
About this study
The study looks into whether administering psychedelic substances that stimulate the serotonin system influences pro-social behavior when compared to administering substances that stimulate the dopamine system in healthy individuals.
Read the detailed description
Psychedelic substances have been shown to be powerful modulators of social perception and behavior during the acute experience. This is of particular interest given that social relationships play a key role in the development and resolution of psychiatric symptoms. However, the neuropharmacological mechanism underlying pro-social effects and time-dependent changes currently remain unclear. This study therefore aims at answering two key questions: 1) Does stimulation of the serotonin system induce lasting effects on pro-social behavior? and 2) Are these effects specific to serotonergic stimulation? The following proposed study will assess these questions by investigating objective, ecologically valid measures of pro-social cognition four weeks after different pharmacological challenges (MDMA, an entactogen and releaser of serotonin, norepinephrine, and dopamine; psilocybin: a classical psychedelic and serotonin 2A receptor agonist, methylphenidate: an amphetamine and norepinephrine-dopamine re-uptake inhibitor) in healthy volunteers.
- Conditions
- Healthy
- Being tested
- Psilocybin, 3,4 Methylenedioxymethamphetamine, Methylphenidate
- Keywords
- MDMA, Psilocybin, Methylphenidate, pro-social behavior, healthy controls, psychedelics, serotonin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PsilocybinDrug
Also called magic mushrooms
Single dose of psilocybin (15mg), orally in form of capsules
3,4 MethylenedioxymethamphetamineDrug
Also called MDMA, Ecstasy
Single dose of MDMA (100mg), orally in form of capsules
MethylphenidateDrug
Also called Ritalin
Single dose of methylphenidate (60mg), orally in form of capsules
| Study group | Role | What they receive |
|---|---|---|
| Psilocybin | Active comparator | 40 participants will receive psilocybin Receives: Drug: Psilocybin |
| MDMA | Active comparator | 40 participants will receive MDMA Receives: Drug: 3,4 Methylenedioxymethamphetamine |
| Methylphenidate | Active comparator | 40 participants will receive methylphenidate Receives: Drug: Methylphenidate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Multifaceted Empathy Test
The Multifaceted Empathy Test is a task assessing the cognitive and emotional aspects of empathy. Participants process 40 photos of people in emotionally charged situations. Each aspect of empathy (implicit and explicit emotional empathy, and cognitive empathy) is tested with 20 positive valence stimuli and 20 negative valence stimuli, yielding a total of 120 trials.
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Moral Inference Task
The Moral Inference task is an approach to evaluate the computational basis of moral inference and its temporal dynamics. Participants observe and predict the decisions of two "agents" who repeatedly choose on administering painful electric shocks to another person in a different room in return for money, and rate them every third trial for their moral character. At the end of the game there is a short trust game. Participants can win actual money in this game (up to 1 CHF).
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Zurich Prosocial Game
The Zurich Prosocial Game is a computer-based pro-social game which allows for assessment of prosocial behavior, considering the influence of helping cost, distress cues in helping behavior, and reciprocity on pro-social behavior through different trial types. Participants can win actual money in this game (up to 6.50 CHF).
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Social Gaze Task
The Social Gaze Task is a paradigm in which participants' gaze is used to control the gaze of a tropomorphic virtual figure. The aim is to capture the reciprocal and interactive nature of joint attention. Participants' gaze behavior is recorded using an eye-tracking device. The outcome measures we will use are pupil size, valence, and arousal ratings.
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Moral Expansion Task
In the Moral Expansion Task, the influence of social distance is elicited by having participants indicate countries with different social distances and decide how much money out of CHF 100 they would like to donate to the Red Cross in each country. One participant's choice is then randomly selected, and the donation is implemented while the chosen participant receives the remaining amount.
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Social Network Questionnaire
The Social Network Questionnaire is used to assess the size of a person's social network and the emotional support and strain experienced from that network. Participants provide the initials of personal contacts from various domains with whom they have had contact with in the past 4 weeks. 28 items are rated on a 6-point scale, asking how much emotional support and emotional burden they have felt from their social contacts. The total score for those items ranges from 28 to 168.
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Pro-social Voting Behavior
The Pro-social Voting Behavior is used to evaluate pro-social voting behavior as a real-world measure of social behavior. The scale consists of 11 items. Each item is rated on a 4-point scale. The total score ranges from 11 to 44. Not all items are accounted equally to capture pro-social voting behavior, as some are reversed.
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Oxford Utilitarianism Scale
The Oxford Utilitarianism Scale measures two dimensions of utilitarian tendencies. The scale consists of 9 items. Each item is rated on a 7-point scale. The total score ranges from 9 to 63.
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Compassion Scale
The Compassion Scale measures an individual's level of compassion towards others. The scale consists of 16 items. Each item is rated on a 5-point scale. The total score ranges from 16 to 80.
Measured: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Inclusion of others in the self
The Inclusion of others in the self is designed to assess the perceived relationship between an individual's self and other people/all living things. It consists of two items. Each item is rated as circles corresponding to a numerical score, ranging from 1 to 8. The total score ranges from 2 to 16.
Measured: t0 - 10 days (+/- 7 days), t0, and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Secondary outcomes (9)
5-Dimensional Altered States of Consciousness Rating Scale
The 5-Dimensional Altered States of Consciousness Rating Scale measures subjective experiences of altered states of consciousness. It contains 94 items, which are formulated as a visual analog scale, assessing different dimensions of altered states of consciousness.
Measured: t0 (the day of substance administration)
5-Dimensional Altered States of Consciousness Rating Scale short
The 5-Dimensional Altered States of Consciousness Rating Scale short is a shorter version of the 5-Dimensional Altered States of Consciousness Rating Scale for measuring subjective experiences of altered states of consciousness. The scale consists of 15 items chosen from the full version, which are formulated as a visual analog scale.
Measured: t0 (the day of substance administration)
Mystical Experience Questionnaire
The Mystical Experience Questionnaire is used to assess mystical experiences. The scale consists of 30 items. Each item is rated on a 6-point scale (from 0 to 5). The total score ranges from 0 to 150.
Measured: t0 (the day of substance administration)
Persisting Effects Questionnaire
The Persisting Effects Questionnaire is used to assess changes in attitudes, moods, behavior, and spiritual experience. The scale consists of 144 items. 140 items are rated on a 6-point scale (from 0 to 5). The last four items use different scaling. The total score ranges from 4 to 724.
Measured: t0 + 4 weeks (+/- 3 days) and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
Epistemic and personal transformation (pre and post versions)
The Epistemic and personal transformation is used to capture the intensity and qualities of epistemic and personal transformation and participants' expectations and desires thereof. Both pre and post versions include open questions and 4 items that are rated on a visual analog scale from 0 to 100. The total score ranges from 0 to 400 for pre and post versions each. The post version additionally captures the substance intake assumption of the participants.
Measured: t0 (the day of substance administration)
Symptom Checklist 90-R
The Symptom Checklist 90-R is used to assess a broad range of psychological problems and symptoms of psychopathology within the past seven days. It consists of 90 items. Each item is rated on a 5-point scale (from 0 to 4). The total score ranges from 0 to 360.
Measured: t0 - 10 days (+/- 7 days) and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
The Positive and Negative Affect Schedule
The Positive and Negative Affect Schedule is used to assess both positive and negative affect. It consists of two 10-item scales, one measuring positive affect and one measuring negative affect. Each item is rated on a 5-point scale (from 0 to 4). The total scores range from 0 to 80.
Measured: t0 - 10 days (+/- 7 days), t0, t0 + 4 weeks (+/- 3 days), and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
FEELINGS
The FEELINGS scales consist of a series of six short questionnaires to assess regulation, self-esteem, satisfaction with life, life orientation, and meaning in life. Emotional Regulation Questionnaire uses a 7-point scale with a total score range from 7 to 70 (10 items). Satisfaction with Life Scale uses a 7-point scale with a total score range from 5 to 35 (5 items). Rosenberg Self-Esteem Scale uses a 4-point scale with a total score range from 10 to 40 (10 items). Life Orientation Test-Revised uses a 5-point scale with a total score range from 10 to 50 (10 items). Lebenssinn-Fragebogen uses a 7-point scale with a total score range from 10 to 70 (10 items). HSF uses a 5-point scale with a total score range from 6 to 30 (6 items).
Measured: t0 - 10 days (+/- 7 days) and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
Ego Consciousness Change of Perspective Questionnaire (1 & 2)
Ego Consciousness Change of Perspective Questionnaire is used to measure the two dimensions Consciousness and Ego. Questions for the acute effects of substance intake (27 items) and questions for the longer-lasting effects (6 items) are included. Each item is rated on a visual analog scale from 0 to 100. The total score ranges from 0 to 3300.
Measured: t0 and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Oct 2023
- Study start24 Oct 2023
- Primary completion22 Sep 2025
- Study completion22 Sep 2025
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 HealthyStudies 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
- Randomised
- Intervention model
- Parallel groups
- Model description
- single-center, double-blind, parallel-group, randomized study design
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 122 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06081179
- Sponsor's protocol ID
- 2A-SC-1
- Status last verified
- Nov 2025
- First submitted
- 25 Sep 2023
- Last updated
- 19 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Preller KH, Vollenweider FX. Modulation of Social Cognition via Hallucinogens and "Entactogens". Front Psychiatry. 2019 Dec 3;10:881. doi: 10.3389/fpsyt.2019.00881. eCollection 2019.
PubMed 31849730Cruwys T, Haslam SA, Dingle GA, Haslam C, Jetten J. Depression and Social Identity: An Integrative Review. Pers Soc Psychol Rev. 2014 Aug;18(3):215-238. doi: 10.1177/1088868314523839. Epub 2014 Apr 12.
PubMed 24727974
Study at a glance
From the registry record, last updated by the sponsor on 19 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Does Serotonin System Stimulation Increase Pro-social Behavior? - A Comparative Pharmacological Neuroscientific Study in Healthy Humans
- ClinicalTrials.gov ID
- NCT06081179
- Acronym / sponsor ID
- 2A-SC-1
- Conditions
- Healthy
- Keywords
- MDMA, Psilocybin, Methylphenidate, pro-social behavior, healthy controls, psychedelics, serotonin
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 122 participants (actual)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Study start
- 24 Oct 2023 (actual)
- Primary completion
- 22 Sep 2025 (actual)
- Study completion
- 22 Sep 2025 (actual)
- First posted
- 13 Oct 2023 (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 study looks into whether administering psychedelic substances that stimulate the serotonin system influences pro-social behavior when compared to administering substances that stimulate the dopamine system in healthy individuals.
Detailed description
Psychedelic substances have been shown to be powerful modulators of social perception and behavior during the acute experience. This is of particular interest given that social relationships play a key role in the development and resolution of psychiatric symptoms. However, the neuropharmacological mechanism underlying pro-social effects and time-dependent changes currently remain unclear. This study therefore aims at answering two key questions: 1) Does stimulation of the serotonin system induce lasting effects on pro-social behavior? and 2) Are these effects specific to serotonergic stimulation? The following proposed study will assess these questions by investigating objective, ecologically valid measures of pro-social cognition four weeks after different pharmacological challenges (MDMA, an entactogen and releaser of serotonin, norepinephrine, and dopamine; psilocybin: a classical psychedelic and serotonin 2A receptor agonist, methylphenidate: an amphetamine and norepinephrine-dopamine re-uptake inhibitor) in healthy volunteers.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
- Model description
- single-center, double-blind, parallel-group, randomized study design
| Arm | Type | Receives |
|---|---|---|
| Psilocybin | Active comparator | Drug: Psilocybin40 participants will receive psilocybin |
| MDMA | Active comparator | Drug: 3,4 Methylenedioxymethamphetamine40 participants will receive MDMA |
| Methylphenidate | Active comparator | Drug: Methylphenidate40 participants will receive methylphenidate |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Healthy male or female at the age of 18-40
- Willing and capable to give informed consent for study participation as documented by signature (Informed Consent Form) after the nature of the study has been thoroughly explained
- Willing to refrain from drinking alcohol the day before testing session, from drinking alcohol and caffeinated drinks at the testing days and from consuming psychoactive substances two weeks before the first investigation visit and for the duration of the study
- Willing to abstain from using drugs that may interfere with the effects of the study medications including sleeping aids, cough medications, beta-blocker or other substances with potentially relevant psychoactive and cardiovascular effects.
- Able and willing to comply with all study requirements
Key exclusion criteria (21 listed)
- Poor knowledge of the German language
- Previous significant adverse response to a hallucinogenic drug (incl. psilocybin), MDMA, or methylphenidate
- Allergy or hypersensitivity to previous use of MDMA, psilocybin, or methylphenidate
- Lifetime history of hallucinogen (incl. psilocybin), MDMA, or methylphenidate use on more than 10 occasions
- Personal and family history of major psychiatric disease (e.g., schizophrenia, schizoaffective disorder, psychosis, major depression, bipolar disorder, psychotic disorder, substance addiction/abuse other than caffeine and nicotine) as defined in the DSM-V (1st and 2nd degree relatives)
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 |
|---|---|---|
| PsilocybinAlso: magic mushroomsSingle dose of psilocybin (15mg), orally in form of capsules | Drug | Psilocybin |
| 3,4 MethylenedioxymethamphetamineAlso: MDMA, EcstasySingle dose of MDMA (100mg), orally in form of capsules | Drug | MDMA |
| MethylphenidateAlso: RitalinSingle dose of methylphenidate (60mg), orally in form of capsules | Drug | Methylphenidate |
Primary outcome
Multifaceted Empathy Test
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Multifaceted Empathy Test is a task assessing the cognitive and emotional aspects of empathy. Participants process 40 photos of people in emotionally charged situations. Each aspect of empathy (implicit and explicit emotional empathy, and cognitive empathy) is tested with 20 positive valence stimuli and 20 negative valence stimuli, yielding a total of 120 trials.
Moral Inference Task
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Moral Inference task is an approach to evaluate the computational basis of moral inference and its temporal dynamics. Participants observe and predict the decisions of two "agents" who repeatedly choose on administering painful electric shocks to another person in a different room in return for money, and rate them every third trial for their moral character. At the end of the game there is a short trust game. Participants can win actual money in this game (up to 1 CHF).
Zurich Prosocial Game
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Zurich Prosocial Game is a computer-based pro-social game which allows for assessment of prosocial behavior, considering the influence of helping cost, distress cues in helping behavior, and reciprocity on pro-social behavior through different trial types. Participants can win actual money in this game (up to 6.50 CHF).
Social Gaze Task
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Social Gaze Task is a paradigm in which participants' gaze is used to control the gaze of a tropomorphic virtual figure. The aim is to capture the reciprocal and interactive nature of joint attention. Participants' gaze behavior is recorded using an eye-tracking device. The outcome measures we will use are pupil size, valence, and arousal ratings.
Moral Expansion Task
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
In the Moral Expansion Task, the influence of social distance is elicited by having participants indicate countries with different social distances and decide how much money out of CHF 100 they would like to donate to the Red Cross in each country. One participant's choice is then randomly selected, and the donation is implemented while the chosen participant receives the remaining amount.
Social Network Questionnaire
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Social Network Questionnaire is used to assess the size of a person's social network and the emotional support and strain experienced from that network. Participants provide the initials of personal contacts from various domains with whom they have had contact with in the past 4 weeks. 28 items are rated on a 6-point scale, asking how much emotional support and emotional burden they have felt from their social contacts. The total score for those items ranges from 28 to 168.
Pro-social Voting Behavior
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Pro-social Voting Behavior is used to evaluate pro-social voting behavior as a real-world measure of social behavior. The scale consists of 11 items. Each item is rated on a 4-point scale. The total score ranges from 11 to 44. Not all items are accounted equally to capture pro-social voting behavior, as some are reversed.
Oxford Utilitarianism Scale
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Oxford Utilitarianism Scale measures two dimensions of utilitarian tendencies. The scale consists of 9 items. Each item is rated on a 7-point scale. The total score ranges from 9 to 63.
Compassion Scale
Time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Compassion Scale measures an individual's level of compassion towards others. The scale consists of 16 items. Each item is rated on a 5-point scale. The total score ranges from 16 to 80.
Inclusion of others in the self
Time frame: t0 - 10 days (+/- 7 days), t0, and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
The Inclusion of others in the self is designed to assess the perceived relationship between an individual's self and other people/all living things. It consists of two items. Each item is rated as circles corresponding to a numerical score, ranging from 1 to 8. The total score ranges from 2 to 16.
9 secondary outcomes
5-Dimensional Altered States of Consciousness Rating Scale
Time frame: t0 (the day of substance administration)
5-Dimensional Altered States of Consciousness Rating Scale short
Time frame: t0 (the day of substance administration)
Mystical Experience Questionnaire
Time frame: t0 (the day of substance administration)
Persisting Effects Questionnaire
Time frame: t0 + 4 weeks (+/- 3 days) and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
Epistemic and personal transformation (pre and post versions)
Time frame: t0 (the day of substance administration)
Symptom Checklist 90-R
Time frame: t0 - 10 days (+/- 7 days) and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
The Positive and Negative Affect Schedule
Time frame: t0 - 10 days (+/- 7 days), t0, t0 + 4 weeks (+/- 3 days), and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
FEELINGS
Time frame: t0 - 10 days (+/- 7 days) and t0 + 16 weeks (+/- 7 days); t0 being the day of substance administration
Ego Consciousness Change of Perspective Questionnaire (1 & 2)
Time frame: t0 and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Nov 2025.
- Background: PubMed 31849730Preller KH, Vollenweider FX. Modulation of Social Cognition via Hallucinogens and "Entactogens". Front Psychiatry. 2019 Dec 3;10:881. doi: 10.3389/fpsyt.2019.00881. eCollection 2019.
- Background: PubMed 24727974Cruwys T, Haslam SA, Dingle GA, Haslam C, Jetten J. Depression and Social Identity: An Integrative Review. Pers Soc Psychol Rev. 2014 Aug;18(3):215-238. doi: 10.1177/1088868314523839. Epub 2014 Apr 12.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
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 Psilocybin, 3,4 Methylenedioxymethamphetamine and Methylphenidate in people with Healthy, run by University of Zurich at 1 site in Switzerland.
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 9 inclusion and 21 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: finished, as of the sponsor's last update on 19 Nov 2025. 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 Switzerland. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Multifaceted Empathy Test (time frame: t0 - 10 days (+/- 7 days) and t0 + 4 weeks (+/- 3 days); t0 being the day of substance administration). The study lists 10 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 NCT06081179, 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 19 Nov 2025.