Direct Comparison of Altered States of Consciousness Induced by LSD, Psilocybin, and DMT in Healthy Participants

NCT06899334 | Recruiting Phase 1 DMC

• 1 other identifier: BASEC 2024-01445
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Healthy

Keywords

Psychedelics; LSD; Psilocybin; DMT

Outcome Measures

Primary Outcomes (1)

• 1. Altered state of consciousness profile (5D-ASC)

  5 Dimensions of Altered States of Consciousness (5D-ASC) consisting of 94 items to be rated on a visual analog scale (0-100 mm), with higher values indicating stronger effects.

  18 months

Secondary Outcomes (17)

• Subjective effects (VASs)

  18 months

• Mystical-type experiences (PES)

  18 months

• Mystical-type experiences (PAE-PS-ext)

  18 months

• 3. Emotional breakthrough inventory (EBI+)

  18 months

• Plasma levels of LSD

  18 months

Study Arms (4)

LSD

EXPERIMENTAL

150 µg lysergic acid diethylamide followed by 20 mg ketanserin intravenously after 3 h

Drug: LSD

Psilocybin

EXPERIMENTAL

30 mg Psilocybin followed by 20 mg ketanserin intravenously after 3 h

Drug: Psilocybin

DMT

EXPERIMENTAL

Dose escalating DMT intravenous infusion up to 2 mg/min followed by 20 mg ketanserin intravenously after 3 h

Drug: DMT

Placebo

PLACEBO COMPARATOR

Placebo followed by 20 mg ketanserin intravenously after 3 h

Drug: Placebo

Interventions

LSD DRUG

A moderate to high oral dose of 150 µg LSD will be administered followed by 20 mg intravenous ketanserin after 3 h

LSD

Psilocybin DRUG

A moderate to high oral dose of 30 mg psilocybin will be administered followed by 20 mg intravenous ketanserin after 3 h

Psilocybin

DMT DRUG

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

DMT

Placebo DRUG

An oral and an intravenous placebo will be administered followed by 20 mg intravenous ketanserin after 3 h

Placebo

Eligibility Criteria

• Age: 25 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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)

Sponsors & Collaborators

• University Hospital, Basel, Switzerland: lead

Study Sites (1)

University Hospital

Basel, 4056, Switzerland

RECRUITING

MeSH Terms

Interventions

Lysergic Acid Diethylamide; Psilocybin

Intervention Hierarchy (Ancestors)

Lysergic Acid; Ergolines; Ergot Alkaloids; Alkaloids; Heterocyclic Compounds; Heterocyclic Compounds, 4 or More Rings; Heterocyclic Compounds, Fused-Ring; Indole Alkaloids; Indoles; Heterocyclic Compounds, 2-Ring; Tryptamines; Indolizidines; Indolizines

Study Officials

• Matthias E Liechti, Prof. Dr. MD

  University Hospital, Basel, Switzerland

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Matthias E Liechti, Prof. Dr. MD

CONTACT

61 328 68 68; matthias.liechti@usb.ch

Mélusine Humbert-Droz, MSc

CONTACT

61 328 48 19; melusine.humbert-droz@usb.ch

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: 4-period, random order, placebo-controlled, double-blind cross-over study

Study Record Dates

• First Submitted: March 14, 2025
• First Posted: March 27, 2025
• Study Start: April 1, 2025
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026
• Last Updated: March 27, 2025

Record last verified: 2025-03

Locations

CH (1)