Role of the Serotonin 5-HT2A Receptor in LSD-induced Altered States of Consciousness (LDR-Study) (LDR)

August 26, 2019 updated by: University Hospital, Basel, Switzerland
Serotonin receptors, especially the 5HT2A receptor, are thought to be involved in the effects of various recreationally used psychedelic substances such as LSD. LSD potently stimulates the 5-HT2A receptor but also 5-HT2B/C, 5-HT1 and dopaminergic receptors. LSD induces acute transient alterations in waking consciousness including visual perceptual alterations, audio-visual synesthesia, derealization and depersonalization. LSD has therefore been used as experimental tool ("psychotomimetic") in modern psychiatric research to study psychotic-like states and model psychosis in healthy subjects [1-5]. However, the dose-effects of 5-HT2A receptor stimulation by LSD has not yet been studied. Additionally, there is still very limited data to what extent the 5HT2A receptor contributes to LSD's effects and its role in the mediation of the full response to LSD at a high dose is unclear. A recent experimental human study showed the 5-HT2A receptor antagonist ketanserin fully blocked the subjective effects of a moderate dose of 100 µg of LSD [6]. But, whether the effects of a high 200 µg oral dose of LSD can be blocked by the selective pharmacological 5-HT2A antagonist ketanserin remains to be tested to confirm the critical role of the 5-HT2A receptor in more pronounced alterations of consciousness and perception. The present study therefore explores the role the 5-HT2A receptor in LSD-induced altered states of consciousness using escalating doses of LSD and the 5-HT2A receptor blocker ketanserin administered before a high dose of LSD.

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.

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.
16

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.
  • Early 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
      • Basel, Switzerland, 4031
        • University Hospital

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

21 years to 61 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Age between 25 and 65 years.
  2. Understanding of the German language.
  3. Understanding the procedures and the risks 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. Women of childbearing potential must have a negative pregnancy test at the beginning of the study. Pregnancy tests are repeated before each study session.
  9. Women of childbearing potential must be willing to use double-barrier birth control
  10. Body mass index 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
  4. Illicit substance use (with the exception of cannabis) more than 10 times or any time within the previous two months.
  5. Pregnant or nursing women.
  6. Participation in another clinical trial (currently or within the last 30 days)
  7. Use of medications that may interfere with the effects of the study medications (any psychiatric medications)
  8. Tobacco smoking (>10 cigarettes/day)
  9. Consumption of alcoholic drinks (>10/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: 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.
Placebo Comparator: Placebo, LSD-25, LSD-50, LSD-100, LSD-200, LSD-200-Ketanserin
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
Drug: Placebo
Capsules containing mannitol looking identical to the other drugs.
Drug: LSD
0.025 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.05 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.1 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD plus 40 mg ketanserin per os, single doses each
Other Names:
  • Lysergic Acid Diethylamide
Placebo Comparator: LSD-25, LSD-50, LSD-100, LSD-200, LSD-200-Ketanserin, Placebo
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
Drug: Placebo
Capsules containing mannitol looking identical to the other drugs.
Drug: LSD
0.025 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.05 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.1 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD plus 40 mg ketanserin per os, single doses each
Other Names:
  • Lysergic Acid Diethylamide
Placebo Comparator: LSD-50, LSD-100, LSD-200, LSD-200-Ketanserin, Placebo, LSD-25
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
Drug: Placebo
Capsules containing mannitol looking identical to the other drugs.
Drug: LSD
0.025 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.05 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.1 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD plus 40 mg ketanserin per os, single doses each
Other Names:
  • Lysergic Acid Diethylamide
Placebo Comparator: LSD-100, LSD-200, LSD-200-Ketanserin, Placebo, LSD-25, LSD-50
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
Drug: Placebo
Capsules containing mannitol looking identical to the other drugs.
Drug: LSD
0.025 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.05 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.1 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD plus 40 mg ketanserin per os, single doses each
Other Names:
  • Lysergic Acid Diethylamide
Placebo Comparator: LSD-200, LSD-200-Ketanserin, Placebo, LSD-25, LSD-50, LSD-100
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
Drug: Placebo
Capsules containing mannitol looking identical to the other drugs.
Drug: LSD
0.025 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.05 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.1 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD plus 40 mg ketanserin per os, single doses each
Other Names:
  • Lysergic Acid Diethylamide
Placebo Comparator: LSD-200-Ketanserin, Placebo, LSD-25, LSD-50, LSD-100, LSD-200
Cross-over within-subjects design with all treatment conditions, separated by a wash-out phase
Drug: Placebo
Capsules containing mannitol looking identical to the other drugs.
Drug: LSD
0.025 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.05 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.1 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD per os, single dose
Other Names:
  • Lysergic Acid Diethylamide
Drug: LSD
0.2 mg LSD plus 40 mg ketanserin per os, single doses each
Other Names:
  • Lysergic Acid Diethylamide

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
Altered states of consciousness
Time Frame: 18 months
total 5D-ASC score (5-Dimensional Altered States of Consciousness Rating Scale)
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
Time Frame: 18 months
VAS (Visual analog scales)
18 months
Subjective effects
Time Frame: 18 months
AMRS scales (Adjective mood rating scale)
18 months
Psychotomimetic effects
Time Frame: 18 months
ESI scale (Eppendorf Schizophrenia Inventory)
18 months
Mystical-type experiences
Time Frame: 18 months
MS scales (Mysticism scale)
18 months
Mystical-type experiences
Time Frame: 18 months
SCQ scales (States of consciousness questionnaire)
18 months
Autonomic effects
Time Frame: 18 months
Blood pressure
18 months
Autonomic effects
Time Frame: 18 months
Heart Rate
18 months
Autonomic effects
Time Frame: 18 months
Body temperature
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, MD, MAS, 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.
November 28, 2017

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.
July 5, 2019

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.
July 11, 2019

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).
September 8, 2017

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.
October 20, 2017

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.
October 25, 2017

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.
August 28, 2019

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.
August 26, 2019

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.
August 1, 2019

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-2017-01348

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

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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