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

This randomised, double-blind, placebo-controlled crossover trial (n=20) conducted by the University Hospital in Basel, Switzerland, aims to investigate the effects of ketanserin, olanzapine, and lorazepam administered after LSD (150µg) on the acute response to LSD in healthy subjects.

LSD is being explored for its potential therapeutic benefits in psychiatric and somatic disorders. The study aims to determine if these drugs can attenuate and shorten the subjective LSD response compared to LSD alone. Additionally, it will examine changes in the quality of the LSD experience and effects on sensorimotor gating and sleep. The trial will provide insight into the receptor mechanisms involved in alterations of consciousness, particularly the role of ongoing 5-HT2A receptor stimulation.

Participants aged between 25 and 65 years will be required to understand German, refrain from illicit psychoactive substances, and follow other study-specific criteria. The trial involves a crossover design with various interventions, including LSD combined with ketanserin, olanzapine, lorazepam, or placebo.

Primary outcome measures include the duration and extent of subjective response to LSD, assessed through visual analogue scales (VAS) and other measures. Secondary outcome measures include alterations of consciousness, mystical-type effects, subjective effects, psychotomimetic effects, effects on mindfulness and decentering, challenging experiences, physiological measures, persisting effects, adverse effects, emotional effects, and sleepiness.

Recruitment began in February 2024, and the estimated completion date is June 2025.

Topic Healthy Subjects
Compound Ketamine LSD Placebo
Country Switzerland
Visit trial
Status Recruiting
Results Published No
Start date 01 February 2024
End date 30 June 2025
Phase Phase I
Design Blinded
Type Interventional
Generation Second
Participants 20
Sex All
Age 25- 65
Therapy No

Trial Details

The main objective of this study is to determine whether administration of ketanserin (40 mg), olanzapine (10 mg), and lorazepam (2 mg) after administration of LSD (150 µg) attenuates and shortens the subjective LSD response (any drug effect) compared to administration of LSD (150 µg) alone

NCT Number NCT05964647

Sponsors & Collaborators

University of Basel
The University of Basel Department of Biomedicine hosts the Liechti Lab research group, headed by Matthias Liechti.

Data attribution

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