Effect of Ketanserin After LSD Administration

Phase 1

Completed

• Conditions: Healthy
• Interventions: Drug: Lysergic Acid Diethylamide; Drug: Ketanserin Placebo; Drug: Ketanserin

• Registration Number: NCT04558294
• Lead Sponsor: University Hospital, Basel, Switzerland

Brief Summary

LSD (lysergic acid diethylamide) is a serotonergic (5-HT) hallucinogen widely used for recreational and/or ethnomedical purposes. LSD is thought to induce its prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. This study investigates whether an LSD experience can be attenuated and shortened using 5-HT2A receptor antagonist ketanserin administration after LSD once the psychedelic effects have established.

Detailed Description

LSD is a so-called "classic" or serotonergic hallucinogen or psychedelic.The effects of LSD have been frequently investigated in the past in both healthy participants and patients. In these studies, LSD produced acute transient alterations in waking consciousness including visual perceptual alterations, audio-visual synesthesia, derealization and depersonalization. Moreover, several of these studies described robust and sustained effects of LSD in patients suffering from addiction, anxiety and depression.

Its psychedelic effects are mainly attributed to its potent partial 5-HT2A receptor agonism. Consistently, administration the 5-HT2A receptor antagonist ketanserin (40 mg) prior to the administration of LSD (100 μg) almost completely prevented the acute effects of LSD in another study of our research group (NCT03321136). The present study hypothesis is that ketanserin (40 mg) administered 1h after LSD shortens and reduces the acute subjective effects of LSD (100 μg) compared to LSD alone (100 μg) followed by placebo in healthy humans. Such a finding would confirm a primarily competitive antagonism of ketanserin and LSD at the 5-HT2A receptor in vivo and indicate that LSD produces its psychedelic effects only when present at the receptor.

Study Timeline

• Study First Submitted: 2020-08-25
• Study First Submitted QC: 2020-09-21
• Study First Posted: 2020-09-22
• Study Start: 2020-10-16
• Primary Completion: 2021-08-28
• Study Completion: 2021-09-29
• Status Verified: 2021-10
• Last Update Submitted: 2021-10-20
• Last Update Posted: 2021-10-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 24

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 and foods 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)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
100 μg LSD + Ketanserin placebo	Ketanserin Placebo	-
100 μg LSD + Ketanserin placebo	Lysergic Acid Diethylamide	-
100 μg LSD + Ketanserin (40mg)	Lysergic Acid Diethylamide	-
100 μg LSD + Ketanserin (40mg)	Ketanserin	-

Primary Outcome Measures

Name	Time	Method
Duration of subjective response	12 months	Visual Analog Scales (VAS) will be repeatedly used to assess subjective alterations in consciousness over time. VAS will be presented as 100 mm long horizontal lines marked with "not at all" on the left and "extremely" on the right. The following VAS will be used: "any effect", "good effect", "bad effect", "fear", "stimulated", "nausea", "tiredness", "alteration of hearing", "alteration of vision", "synesthesia", "alteration in sense of time", "the boundaries between myself and my surroundings seemed to blur", "talkative", "open", "trust" and "my focus is directed: outward/inward". Subjects will mark the scale with vertical lines.
Extent of subjective response	12 months	Visual Analog Scales (VAS) will be repeatedly used to assess subjective alterations in consciousness over time. VAS will be presented as 100 mm long horizontal lines marked with "not at all" on the left and "extremely" on the right. The following VAS will be used: "any effect", "good effect", "bad effect", "fear", "stimulated", "nausea", "tiredness", "alteration of hearing", "alteration of vision", "synesthesia", "alteration in sense of time", "the boundaries between myself and my surroundings seemed to blur", "talkative", "open", "trust" and "my focus is directed: outward/inward". Subjects will mark the scale with vertical lines.
Plasma concentrations of LSD	12 months	LSD plasma concentrations will be measured repeatedly over time using LC-MS/MS techniques (nanogram per milliliter scale).
Plasma concentrations of Ketanserin	12 months	LSD plasma concentrations will be measured repeatedly over time using Liquid chromatography-mass spectrometry (LC-MS)/MS techniques (nanogram per milliliter scale).

Secondary Outcome Measures

Name	Time	Method
5 dimensions of altered state of consciousness (5D-ASC) profile total score	12 months	Visual analog scale consisting of 94 items. Constructed of five scales and allows assessing mood, anxiety, derealization, depersonalization, changes in perception, auditory alterations, and reduced vigilance. Scales will be presented as 100 mm long horizontal lines marked with vertical lines by the participant.
Adjective mood rating scale (AMRS)	12 months	The adjective mood rating scale (AMRS or EWL60S) is a 60-item 4-point Likert scale ("not at all", "somewhat", "rather", "strongly") that allows repeated assessment of mood in 6 dimensions: activation, inactivation, well-being, anxiety/depressed mood, extroversion and introversion, and emotional excitability.The AMRS consists of subscales measuring "activation", "positive mood", "extroversion", "introversion", "inactivation", and "emotional excitability".
States of consciousness questionnaire (SCQ)	12 months	This 100-item questionnaire is rated on a 6-point scale (0=none, not at all; 1=so slight cannot decide; 2=slight; 3=moderate; 4=strong (equivalent in degree to any previous strong experience or expectation of this description); 5=extreme (more than ever before in my life and stronger than 4)). Forty-three items embedded into this questionnaire comprise the Mystical Experience Questionnaire (MEQ). The 43 items provide scale scores for each of seven domains of mystical experiences: internal unity (pure awareness, a merging with ultimate reality), external unity (unity of all things, all things are alive, all is one), sense of sacredness (reverence, sacred), noetic quality (encounter with ultimate reality, more real than everyday reality), transcendence of time and space, deeply felt positive mood (joy, peace, love), paradoxicality/ineffability (claim of difficulty in describing the experience in words).
Blood pressure	12 months	Repeatedly measured using blood pressure / pulse apparatus (mmHg scale).
Heart rate	12 months	Repeatedly measured using blood pressure / pulse apparatus (beats per minute scale).
Body temperature	12 months	Repeatedly measured using ear thermometer (degree Celsius scale).
Pupil diameter	12 months	Repeatedly measured using pupil distance meter (millimeter scale).
Elliot Humility Scale (EHS)	12 months	Assesses the personality trait humility through 13 items on a 5-point Likert scale ranging from "strongly disagree" to "strongly agree".
Jankowski Humility Scale (JHS)	12 months	Assesses the personality trait humility through 18 items on a 5-point Likert scale ranging from "not at all" to "strongly".
Arnett Inventory of Sensation Seeking (AISS-d)	12 months	Assesses the personality trait of sensation seeking, which is is defined as a need for novel and intense stimulation. It uses 20 items using 4-point scales (1 = "describes me very well" to 4 = "does not describe me at all").
Freiburger Persönlichkeitsinventar (FPI)	12 months	The FPI-R version comprises 138 items and covers 12 dimensions of personality: life satisfaction, social orientation, performance orientation, inhibition, excitability, aggressiveness, stress, physical complaints, health concerns, openness, as well as the secondary factors according to Eysenck's Extraversion and Emotionality (Neuroticism). It uses a 2-point scale ("true" and "not true").
Saarbrücker Persönlichkeitsfragebogen (SPF)	12 months	The SPF defines empathy as the "reactions of one individual to the observed experiences of another." It assesses 28-items on a 5-point Likert scale ranging from "Does not describe me well" to "Describes me very well". The measure has 4 subscales (Perspective Taking, Fantasy, Empathic Concern, Personal Distress) each made up of 7 different items.
Defense Style Questionnaire (DSQ-40)	12 months	The DSQ-40 can provide scores for 20 individual defenses, and scores for the three factors "mature", "neurotic", and "immature". Each item is evaluated on a scale from 1 to 9, where "1" indicates "completely disagree" and "9" indicates "fully agree".

Trial Locations

Locations (1)

Clinical Pharmacology & Toxicology, University Hospital Basel; 🇨🇭 Basel, Switzerland