Effect of Ketanserin, Olanzapine, and Lorazepam After LSD Administration on the Acute Response to LSD in Healthy Subjects

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 any drug effect", "good drug effect", "bad drug effect", "stimulated", "tiredness", "fear", "nausea", "alteration of vision", "alteration of hearing", "sounds seem to influence what I see", "alteration of sense of time", "the boundaries between myself and my surroundings seem to blur", "I gain insights into contexts that were previously mysterious to me", "opposites dissolve", "talkative", "happy", and "trust". Additionally, "my perception is…" from "muted" to "clear", "I feel …" from "relaxed" to "tense", and "I feel my thoughts are …" from "sluggish" to "racing". Subjects will mark the scale with vertical lines.

Area under the curve (AUEC), Emax, of the VAS-Item "any drug effect"

Altered States of Consciousness 5 Dimensions of Altered States of Consciousness (5D-ASC) assesses mood, anxiety, derealization, depersonalization, changes in perception, auditory alterations, and reduced vigilance. The questionnaire is consisting of 94 items to be rated on a visual analog scale (horizontal line, 100 mm, marked with "not at all" on the left and "extremely" on the right), with higher values indicating stronger effects. Subjects will mark the scale with vertical lines.

Mystical-type experience questionnaire (MEQ) assesses with 30 items (embedded into the SCQ) the mystical experiences on a 6-point Likert scale ranging from 0 ("not at all") to 5 ("extremely").

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 any drug effect", "good drug effect", "bad drug effect", "stimulated", "tiredness", "fear", "nausea", "alteration of vision", "alteration of hearing", "sounds seem to influence what I see", "alteration of sense of time", "the boundaries between myself and my surroundings seem to blur", "I gain insights into contexts that were previously mysterious to me", "opposites dissolve", "talkative", "happy", and "trust". Additionally, "my perception is…" from "muted" to "clear", "I feel …" from "relaxed" to "tense", and "I feel my thoughts are …" from "sluggish" to "racing". Subjects will mark the scale with vertical lines.

Adjective Mood Rating Scale (AMRS) assesses the occurrence and intensity of 60 moods on a 4-point Likert scale ranging from "not at all" to "extremely".

The Addiction Research Center Inventory (ARCI) is a true-false questionnaire with five empirically derived scales. The scale is administered once before, after 3 h, 10 h, and 24 h after LSD administration.

The aberrant salience inventory (ASI) is a 29-item questionnaire rated as "yes" or "no" measuring trait aberrant salience, which has been hypothesized to be important for psychosis and psychotic disorders. The questionnaire will be administered once at the end of the session and subjects will be instructed to retrospectively rate peak alterations during the study session.

The psychotomimetic states inventory (PSI) consists of 48 items measuring "psychosis-like" experiences and is one of the most widely used measure of drug-induces psychotic-like effects. Items will be scored on a 4-point scale (0 = never to 3 = strongly). The questionnaire will be administered once at the end of the session and subjects will be instructed to retrospectively rate peak alterations during the study session.

The 39-item Five Facet Mindfulness Questionnaire (FFMQ) measures five facets of a general tendency to be mindful in daily life. The FFMQ will be completed by the participants at screening, the beginning of each study session (to assess respective baseline) and will be handed in to the participants at the end of the respective study visit and participants will be asked to complete the FFMQ at home 36 h after the study drug has been administered.

The 20-item Experience Questionnaire (EQ) measures decentering and ruminating. Decentering is defined as looking at one's own feelings from a distance, in an observing and objective way. The EQ will be completed by the participants at screening, at the beginning of each study session (to assess respective baseline) and will be handed in to the participants at the end of the respective study visit, and participants will be asked to complete the EQ at home 36 h after the study drug has been administered

The Challenging Experiences Questionnaire (CEQ) was developed to characterize challenging experiences with psilocybin. The 26-item questionnaire is rated on a 6-point Likert scale ranging from 0 (none, not at all) to 5 (extreme, more than ever before in my life). The CEQ includes seven factors: "Fear"; "Grief"; "Physical Distress"; "Insanity"; "Isolation"; "Death"; "Paranoia", and a total score (Total) is calculated over all items. 9. The validated German version of the CEQ 153 will be administered once at the end of the session and subjects will be instructed to retrospectively rate their experiences during peak alterations during the study session.

Prepulse inhibition (PPI) of the acoustic startle response is an operational measure of sensorimotor gating that can be measured in animals and humans and serves as a preclinical model for schizophrenia. LSD and other serotonergic 5-HT2A agonists disrupt PPI in animals and in humans and PPI is also disrupted in schizophrenic patients. We will measure effects of LSD on sensorimotor gating function.

Blood pressure, assessed 21 times during each study session via systolic and diastolic blood pressure.

Heart rate, assessed 21 times during each study session via heart rate, Emax.

Body temperature assessed 20 times during each study session via tympanic body temperature.

Pupil size, assessed 8 times during each study session via pupilometer.

LSD and metabolites concentrations measured in the blood plasma, assessed 17 times during each study session via blood samples.

Ketanserin concentrations measured in the blood plasma, assessed 17 times during each study session via blood samples.

Olanzapine concentrations measured in the blood plasma, assessed 17 times during each study session via blood samples.

Lorazepam concentrations measured in the blood plasma, assessed 17 times during each study session via blood samples.

The Dreem® headband will record electroencephalographic (EEG; five dry electrodes yielding seven derivations), acceleration (3D accelerometer), and heart rate (red-infrared pulse oximeter) activity. We will further calculate sleep variables of %REM (REM sleep duration divided by total sleep duration), REM Latency (duration of non-REM sleep before the first REM phase), and REM Efficiency (REM sleep duration divided by the total REM episode duration) for each night. We will start the measurement 11 h after LSD administration until the end of the study day.

The 143-item Johns Hopkins University Persisting Effects Questionnaire (PEQ) seeks information about changes in attitude, mood, behavior, and spiritual experience items are rated on a six-point scale. The PEQ will be administered at the EOS visit.

The adapted list of complaints (LC) consists of 50 items offering a global score measuring physical and general discomfort. The LC list is administered before, 12 h after LSD administration with reference to all complaints arising since the LSD administration, and at the end of the session with reference to complaints throughout the night. Subjects will additionally be asked to report any adverse events during the sessions or/and between study sessions as assessed at the beginning of the next session and at the EOS visit.

Multifaceted Empathy Test (MET), effects on empathy in computer tests, assessed one time during each study session.

The Karolinska Sleepiness Scale (KSS) measures the subjective level of sleepiness 161. The scale shows a 10-point scale from "1 - extremely alert" to "10 - extremely sleepy - cannot stay awake". The KSS will be assessed at the beginning and repeatedly in the evening and next morning of the study session

Assessed one time during the screening via the NEO-Five-Factor-Inventory (NEO-FFI). The NEO-FFI assesses 5 personality traits (openness to experience, conscientiousness, extraversion, agreeableness and neuroticism) consisting of of 60 items. Each item is evaluated on a scale from -- "strong disagreement" to ++ "strong agreement".

Assessed one time during the screening via Freiburger Personality Inventory (FPI). 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").

Assessed one time during the screening via Saarbrücker Personality Questionnaire (SPF). 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.

Assessed one time during the screening via HEXACO personality inventory (Honesty-Humility, Emotionality, Extraversion, Agreeableness, Conscientiousness, and Openness). The HEXACO consists of 100 items. Each item is evaluated on a scale from 1 "strong disagreement" to 5 "strong agreement".

Assessed one time during the screening via Defense Style Questionnaire (DSQ-40). 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".