CompletedPhase 1

Acute Effects of MDMA Co-administration on the Response to Psilocybin in Healthy Subjects

NCT06884514 · MDMA-Psilo · University Hospital, Basel, Switzerland

Closed to entry

Status

Not accepting participants

Phase 1

Phase

Target enrolment

Study sites

Outside the US

What it is testing

Summary

The acute subjective effects of serotonin (5-HT)2A receptor stimulation with psilocybin in humans are mostly positive. However, negative effects such as anxiety, paranoid thinking, or loss of trust towards other people are common effects, depending on the dose administered, the personality traits of the person consuming it (set), or the environment in which psilocybin is taken (setting). Negative psychedelic effects may cause acute distress to the subject and acute anxiety has been linked to less favorable long-term outcomes in patients experimentally treated with psilocybin or similar substances for the treatment of depression. The 5-HT and oxytocin releaser 3,4-methylenedioxymethamphetamine (MDMA) reliably induces positive mood, euphoria, comfort, empathy, and feelings of trust. If administered in combination with psilocybin, MDMA may increase positive subjective drug effects including positive mood, empathy, and trust and reduce negative emotions and anxiety associated with psilocybin and overall produce a more positive over negative experience. The present study will assess subjective and autonomic effects of psilocybin alone and in combination with MDMA.

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

Acute Subjective effects I
Measured over through study completion, an average of 18 months
Acute Subjective effects II
Measured over through study completion, an average of 18 months
Acute Subjective effects III
Measured over through study completion, an average of 18 months
Acute autonomic effects I (blood pressure)
Measured over through study completion, an average of 18 months
Acute autonomic effects I (heart rate)
Measured over through study completion, an average of 18 months
Acute autonomic effects III (body temperature)
Measured over through study completion, an average of 18 months
Acute autonomic effects IV (ECG QT-time)
Measured over through study completion, an average of 18 months

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

25 Years to 65 Years

Ages

All

Sex

Accepted

Healthy volunteers

Inclusion Criteria: 1. Age between 25 and 65 years. 2. Understanding of the German language. 3. Understanding the procedures and the risks that are associated with the study. 4. Participants must be willing to adhere to the protocol and sign the consent form. 5. Participants must be willing to refrain from taking illicit psychoactive substances during the study. 6. Participants must be willing to drink only alcohol-free liquids and no coffee, black or green tea, or energy drink after midnight of the evening before the study session, as well as during the study day. 7. Participants must be willing not to drive a traffic vehicle or to operate machines within 48 h after substance administration. 8. Willing to use effective birth control throughout study participation. 9. Body mass index between 18-29 kg/m2. Exclusion Criteria: 1. Chronic or acute medical condition 2. Current or previous major psychiatric disorder 3. Psychotic disorder in first-degree relatives, not including psychotic disorders secondary to an apparent medical reason, e.g. brain injury, dementia, or lesions of the brain. 4. Hypertension (SBP\>140/90 mmHg) or hypotension (SBP\<85 mmHg) 5. Illicit substance use (not including cannabis) more than 20 times or any time within the previous month 6. Pregnant or nursing women. 7. Participation in another clinical trial (currently or within the last 30 days). 8. Use of medications that may interfere with the effects of the study medications. 9. Tobacco smoking (\>10 cigarettes/day). 10. Consumption of alcoholic drinks (\>15 drinks/week).

Where

1 study site

Facility	City	Region	Country
University Hospital Basel	Basel	—	Switzerland

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.

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NCT06884514 on ClinicalTrials.gov →

Last updated in the registry 2026-06-25. Registry records change; this page reflects the data build of 2026-08-25.

Where this trial sits

Substance

All 48 trials from University Hospital, Basel, Switzerland →