Direct Comparison of Altered States of Consciousness Induced by LSD, Psilocybin, and DMT in Healthy Participants
Direct Comparison of Altered States of Consciousness Induced by LSD, Psilocybin, and DMT in a Randomized, Placebo-controlled, Cross-over Trial in Healthy Participants (LPD-Study)
University Hospital, Basel, Switzerland
24 participants
Apr 1, 2025
INTERVENTIONAL
Conditions
Summary
The primary objective of this study is to determine whether equivalent moderately high doses of LSD, psilocybin, and DMT produce qualitatively similar peak effects when the effect duration is standardized with ketanserin. A DMT infusion mimicking oral LSD and psilocybin administrations will be tested, as well as intravenously administered ketanserin.
Eligibility
Inclusion Criteria7
- Good understanding of the German language
- Understanding of procedures and risks associated with the study
- Willing to adhere to the protocol and signing of the consent form
- Willing to refrain from the consumption of illicit psychoactive substances during the study
- Willing not to operate heavy machinery within 48 h after administration of a study substance
- Willing to use effective birth control throughout study participation
- Body mass index 17 - 34.9 kg/m2
Exclusion Criteria13
- Relevant chronic or acute medical condition
- Current or previous major psychiatric disorder (e.g. psychotic disorder)
- Psychotic disorder or bipolar disorder in first-degree relatives
- Hypertension (SBP>140/90 mmHg) or hypotension (SBP<85 mmHg)
- Bradycardia (< 45 bpm)
- Prolonged QTc interval (males: >450 ms, females: >470 ms)
- AV block II° (Mobitz type and Webckebach type) and III°
- Hallucinogenic substance use (not including cannabis) more than 20 times or any time within the previous two months
- Pregnancy or current breastfeeding
- Participation in another clinical trial (currently or within the last 30 days)
- Use of medication that may interfere with the effects of the study medication
- Tobacco smoking (>10 cigarettes/day)
- Excessive consumption of alcoholic beverages (>15 drinks/week)
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Interventions
A moderate to high oral dose of 150 µg LSD will be administered followed by 20 mg intravenous ketanserin after 3 h
A moderate to high oral dose of 30 mg psilocybin will be administered followed by 20 mg intravenous ketanserin after 3 h
A moderate to high, dose-escalating, intravenous infusion up to 2 mg/min DMT will be administered followed by 20 mg intravenous ketanserin after 3 h
An oral and an intravenous placebo will be administered followed by 20 mg intravenous ketanserin after 3 h
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT06899334