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

March 20, 2025 updated by: University Hospital, Basel, Switzerland

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)

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Lysergic acid diethylamide (LSD), psilocybin, and N,N-dimethyltryptamine (DMT) are serotonergic hallucinogens (psychedelics) and currently investigated as therapeutic tools for the treatment of various psychiatric disorders. They are usually administered in a dose range which induces an alteration of consciousness via the stimulation of the serotonin (5-HT)2A receptor. However, there are differences in the receptor activation profiles between the three substances that may induce different subjective effects. Moreover, they exhibit different pharmacokinetic qualities. In comparative studies of LSD and psilocybin blinding was impaired by the different duration of subjective effects. This study aims to ensure blinding by ending all experiences at the same time with the 5HT2A antagonist ketanserin. Moreover, no study has yet directly compared DMT to LSD and psilocybin. The DMT infusion will be modeled in accordance with the course of an oral LSD and psilocybin administration. Therefore, the LPD-study compares the acute and subacute effects of LSD, psilocybin, and DMT while standardizing the time course and the duration of action for all substances.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
24

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Switzerland
      • Basel, Switzerland, 4056
        • Recruiting
        • University Hospital
        • Contact:
        • Contact:
        • Principal Investigator:
          • Matthias E Liechti, Prof. Dr. MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Good understanding of the German language
  2. Understanding of procedures and risks associated with the study
  3. Willing to adhere to the protocol and signing of the consent form
  4. Willing to refrain from the consumption of illicit psychoactive substances during the study
  5. Willing not to operate heavy machinery within 48 h after administration of a study substance
  6. Willing to use effective birth control throughout study participation
  7. Body mass index 17 - 34.9 kg/m2

Exclusion Criteria:

  1. Relevant chronic or acute medical condition
  2. Current or previous major psychiatric disorder (e.g. psychotic disorder)
  3. Psychotic disorder or bipolar disorder in first-degree relatives
  4. Hypertension (SBP>140/90 mmHg) or hypotension (SBP<85 mmHg)
  5. Bradycardia (< 45 bpm)
  6. Prolonged QTc interval (males: >450 ms, females: >470 ms)
  7. AV block II° (Mobitz type and Webckebach type) and III°
  8. Hallucinogenic substance use (not including cannabis) more than 20 times or any time within the previous two months
  9. Pregnancy or current breastfeeding
  10. Participation in another clinical trial (currently or within the last 30 days)
  11. Use of medication that may interfere with the effects of the study medication
  12. Tobacco smoking (>10 cigarettes/day)
  13. Excessive consumption of alcoholic beverages (>15 drinks/week)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: LSD
150 µg lysergic acid diethylamide followed by 20 mg ketanserin intravenously after 3 h
Drug: LSD
A moderate to high oral dose of 150 µg LSD will be administered followed by 20 mg intravenous ketanserin after 3 h
Experimental: Psilocybin
30 mg Psilocybin followed by 20 mg ketanserin intravenously after 3 h
Drug: Psilocybin
A moderate to high oral dose of 30 mg psilocybin will be administered followed by 20 mg intravenous ketanserin after 3 h
Experimental: DMT
Dose escalating DMT intravenous infusion up to 2 mg/min followed by 20 mg ketanserin intravenously after 3 h
Drug: DMT
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
Placebo Comparator: Placebo
Placebo followed by 20 mg ketanserin intravenously after 3 h
Drug: Placebo
An oral and an intravenous placebo will be administered followed by 20 mg intravenous ketanserin after 3 h

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
1. Altered state of consciousness profile (5D-ASC)
Time Frame: 18 months
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 Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Subjective effects (VASs)
Time Frame: 18 months
Visual Analog Scales assessing the intensity and duration of subjective effects on a scale from 0 - 100 percent with higher scores representing more intense effects.
18 months
Mystical-type experiences (PES)
Time Frame: 18 months
This 100-item Psychedelic Experience Questionnaire/Scale (PES100) is rated on a six-point scale (0 indicating "not at all" and 5 indicatin "extremely"). It comprises distractor items as well as subscales which measure mystical-type effects.
18 months
Mystical-type experiences (PAE-PS-ext)
Time Frame: 18 months
This Phenomenological-Autobiographical-Existential Psychedelic Scale extended (PAE-PS-ext) questionnaire rates psychedelic experiences with a focus on phenomenological, autobiographical, and existential psychedelic experiences (scale from 0 - 100 percent with higher scores representing more intense effects).
18 months
3. Emotional breakthrough inventory (EBI+)
Time Frame: 18 months
This 18-item questionnaire is a visual analog scale (from 0 - 100 percent with higher scores representing more intense effects) assessing emotional breakthrough throughout the study sessions.
18 months
Plasma levels of LSD
Time Frame: 18 months
Assessed 20 times on each study day via blood samples
18 months
Plasma levels of psilocybin
Time Frame: 18 months
Assessed 20 times on each study day via blood samples
18 months
Plasma levels of DMT
Time Frame: 18 months
Assessed 20 times on each study day via blood samples
18 months
Plasma levels of ketanserin
Time Frame: 18 months
Assessed 20 times on each study day via blood samples
18 months
Plasma levels of oxytocin
Time Frame: 18 months
Assessed 2 times on each study day via blood samples
18 months
Plasma levels of prolactin
Time Frame: 18 months
Assessed 2 times on each study day via blood samples
18 months
Plasma levels of cortisol
Time Frame: 18 months
Assessed 2 times on each study day via blood samples
18 months
Autonomic effects I
Time Frame: 18 months
Assessed 16 times on each study day via systolic and diastolic blood pressure
18 months
Autonomic effects II
Time Frame: 18 months
Assessed 16 times on each study day via heart rate
18 months
Autonomic effects III
Time Frame: 18 months
Assessed one time at screening visit and twice on each study day via ECG (QT-time)
18 months
Adverse effects (B-LR)
Time Frame: 18 months
The 2011 revised Beschwerden-Liste (B-LR) consists of a 40-item list covering a wide variety of symptoms and complaints that are answered with a four-point intensity-scoring ranging from 0 indicating "not at all" to 3 indicating "strong."
18 months
Adverse effects (SPSI)
Time Frame: 18 months
The Swiss Psychedelic Side Effects Inventory evaluates side effects associated with psychedelics using a binary "yes or no" approach. Severity is recorded using a three-point intensity scale ranging from 1 indicating "light" to 3 indicating "strong." The impact is recorded using a five-point scale ranging from -2 "very disadvantageous" to +2 "very advantageous." The relation to the drug is recorded using a five-point scale ranging from 0 indicating "unknown" to 4 indicating "certain."
18 months
Adverse Events (AE)
Time Frame: 18 months
Any report of adverse events will be recorded on a AE-Form.
18 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital, Basel, Switzerland

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Matthias E Liechti, Prof. Dr. MD, University Hospital, Basel, Switzerland

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 14, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 20, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 27, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 27, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 20, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • BASEC 2024-01445

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings