Comparative Acute Effects of LSD, Psilocybin and Mescaline (LPM)

January 23, 2024 updated by: University Hospital, Basel, Switzerland

Comparative Acute Effects of LSD, Psilocybin and Mescaline in a Random-Order Placebo-Controlled Cross-Over Study in Healthy Subjects

LSD, psilocybin and mescaline are widely used for recreational and ethnomedical purposes. All three substances are thought to induce prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. However, there are differences in the substances' molecular structures and receptor activation profiles which may induce differential subjective effects. To date, there are no modern studies comparing LSD, psilocybin and mescaline directly within the same clinical study and research subjects using validated psychometric tools. Therefore, the LPM-Study compares the acute effects of LSD, psilocybin, mescaline and placebo in a double-blind, placebo-controlled, 4-period cross-over design with four treatment conditions: 1) 100 μg LSD, 2) 20 mg psilocybin, 3) 300 or 500 mg mescaline, and 4) placebo.

Study Overview

Status

Status

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

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

LSD (lysergic acid diethylamide), psilocybin (the active substance in "magic mushrooms") and mescaline (the active substance in Peyote and San Pedro cacti) are serotonergic hallucinogens widely used for recreational and/or ethnomedical purposes. LSD, psilocybin and mescaline are thought to induce prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. However, there are differences in their molecular structures (LSD: ergoline, psilocybin: tryptamine; mescaline: phenethylamine)and receptor activation profiles which may induce different subjective effects. To date, there are no modern studies comparing these three substances directly within the same clinical study and research subjects using validated psychometric tools. Therefore, the LPM-Study compares the acute effects of LSD, psilocybin, mescaline and placebo in a double-blind, placebo-controlled, 4-period cross-over design with four treatment conditions: 1) 100 μg LSD, 2) 20 mg psilocybin, 3) 300 or 500 mg mescaline, and 4) placebo. The main objective of this study is to determine whether LSD, psilocybin and mescaline produce qualitatively similar subjective alterations of mind and associated brain activity patterns despite their unique receptor activation profiles. The study investigates psychological (psychometry), physiological and neuronal (magnetic resonance imaging) variables. The LPM-Study provides insight into the acute effects profiles of three serotonergic hallucinogens. It will enhance the understanding of psychedelic-induced altered states of consciousness in humans and will be relevant for the fields of psychiatry, psychology, and forensic toxicology.

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 (Actual)

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.
32

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 Locations

  • Switzerland
    • BS
      • Basel, BS, Switzerland, 4031
        • University Hospital Basel, Clinical Trial Unit

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

25 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Age between 25 and 65 years old
  2. Sufficient understanding of the German language
  3. Understanding of procedures and risks associated with the study
  4. Willing to adhere to the protocol and signing of the consent form
  5. Willing to refrain from the consumption of illicit psychoactive substances during the study
  6. Abstaining from xanthine-based liquids from the evenings prior to the study sessions to the end of the study days
  7. Willing not to operate heavy machinery within 48 hours after substance administration
  8. Willing to use double-barrier 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 or bipolar disorder in first-degree relatives
  4. Hypertension (>140/90 mmHg) or hypotension (SBP<85 mmHg)
  5. Hallucinogenic substance use (not including cannabis) more than 20 times or any time within the previous two months
  6. Pregnancy or current breastfeeding
  7. Participation in another clinical trial (currently or within the last 30 days)
  8. Use of medication that may interfere with the effects of the study medication
  9. Tobacco smoking (>10 cigarettes/day)
  10. Consumption of alcoholic beverages (>20 drinks/week)
  11. Failure of MRI-related criteria

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: Quadruple

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-100
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Drug: LSD
LSD 0.1 mg per os, single dose OR Psilocybin 20 mg per os, single dose OR Mescaline 300 mg per os, single dose OR Placebo
Active Comparator: Psilocybin-20
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Drug: Psilocybin
Psilocybin 20 mg per os, single dose
Active Comparator: Mescaline-300/500
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Drug: Mescaline
Mescaline 300 mg or 500 mg per os, single dose
Placebo Comparator: Placebo
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Other: Placebo
Placebo (Mannitol)

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
5 Dimensions of Altered States of Consciousness (5D-ASC)
Time Frame: 18 months
5D-ASC subscale ratios
18 months
fMRI resting state functional connectivity (RSFC)
Time Frame: 18 months
Spontaneous low-frequency fluctuations in BOLD signal during resting state
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
Visual Analog Scale (VAS)
Time Frame: 18 months
Assesses the intensity and duration of subjective effects on a scale from 0% - 100% with higher scores representing more intense effects
18 months
States of Consciousness questionnaire (SCQ)
Time Frame: 18 months
Assesses the emergence and intensity of phenomenons occurring in altered states of consciousness on a 6-point Likert scale ranging from 0 ("not at all") to 5 ("extremely")
18 months
Blood pressure
Time Frame: 18 months
Assessment of sympathetic activation
18 months
Heart rate
Time Frame: 18 months
Assessment of sympathetic activation
18 months
Body temperature
Time Frame: 18 months
Assessment of sympathetic activation
18 months
Pupil size
Time Frame: 18 months
Assessment of sympathetic activation
18 months
Drug plasma levels
Time Frame: 18 months
Plasma levels of investigational drugs
18 months
Oxytocin levels
Time Frame: 18 months
Levels of oxytocin in blood plasma
18 months
Blood-derived neurotrophic factor (BDNF)
Time Frame: 18 months
Blood plasma levels of BDNF
18 months
Renal clearance values
Time Frame: 18 months
Renal clearance values of investigational drugs through urine recovery
18 months
NEO-Five-Factor-Inventory (NEO-FFI)
Time Frame: 18 months
Assesses personality traits
18 months
Freiburger Persönlichkeitsinventar (FPI)
Time Frame: 18 months
Assesses personality traits
18 months
Saarbrücker Persönlichkeitsfragebogen (SPF)
Time Frame: 18 months
Assesses personality traits
18 months
Adjective Mood Rating Scale (AMRS)
Time Frame: 18 months
Assesses the occurrence and intensity of 60 moods on a 4-point Likert scale ranging from "not at all" to "extremely"
18 months
Mysticism Scale (MS)
Time Frame: 18 months
Assesses the occurrence and intensity of mystical qualities in altered states of consciousness on a 9-point Likert scale ranging from -4 ("extremely inapplicable") to +4 ("extremely applicable"), with higher values indicating a more intense experience
18 months
Elliot Humility Scale (EHS)
Time Frame: 18 months
Assesses the personality trait humility through 13 items on a 5-point Likert scale ranging from "strongly disagree" to "strongly agree"
18 months
Jankowski Humility Scale (JHS)
Time Frame: 18 months
Assesses the personality trait humility through 18 items on a 5-point Likert scale ranging from "not at all" to "strongly"
18 months
Arnett Inventory of Sensation Seeking (AISS-d)
Time Frame: 18 months
Assesses personality traits
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., 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 (Actual)

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.
May 19, 2020

Primary Completion (Actual)

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.
September 2, 2022

Study Completion (Actual)

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.
September 2, 2022

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).
January 7, 2020

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.
January 9, 2020

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.
January 14, 2020

Study Record Updates

Last Update Posted (Estimated)

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.
January 24, 2024

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.
January 23, 2024

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.
January 1, 2024

More Information

Terms related to this study

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 2019-02023

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

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