Clinical trial NCT05976698: LSD-Perceptual-Choice-Study
Official title: Effects of LSD on Perceptual Decision-making in Healthy Subjects
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: LSD Reaction
Keywords: neural and behavioral indicators
serotonergic system
perceptual decision-making
Lead sponsor: University Hospital, Basel, Switzerland
Sponsor class: OTHER
Collaborators: name: University of Basel
name: University Psychiatric Clinics Basel
First posted: 2023-08-04
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Randomized, double-blinded, cross-over study
Primary purpose: BASIC_SCIENCE

Brief summary: The aim of the study is to characterize the effects of low doses of LSD (d-lysergic acid diethylamide) on behavioral and neural indicators of feedback and feedforward signaling in perceptual decision-making.

Detailed description: The study team will subject healthy participants to multiple perceptual decision-making tasks after the administration of low doses of LSD (d-lysergic acid diethylamide) as a pharmacological challenge. The investigators want to illuminate the behavioral and neural effects of psychedelics on prior beliefs and evidence processing. Each subject will participate in 3 x 5 h study sessions separated by at least 7 days. Subjects will be under continuous supervision until approximately 4.5h after substance administration. The participants are asked to perform the following cognitive tasks alongside EEG measurement after administration of either LSD or placebo: Changepoint task, history bias task, surround suppression task, auditory steady-state response paradigm, motor localizer task.

Eligibility criteria: Inclusion Criteria:

* Willingness to adhere to the study protocol and sign the consent form
* ≥ 18 and ≤ 65 years of age at Screening
* Body mass index 18-29
* Fluent understanding of German
* Normal or corrected-to-normal vision
* Willingness to not operate a traffic vehicle or heavy machinery 24 hours after substance administration
* Willingness to refrain from taking illicit psychoactive substances, including cannabis, for the duration of the study
* Willingness to not consume more than one alcoholic standard drink the night before the study sessions and not consume alcohol for 24 h after each study session
* Willingness to abstain from xanthine-based liquids from the evenings prior to the study sessions and during the sessions
* Willingness to use effective birth-control throughout the study duration
* Adequate task performance in the decision-making tasks during a practice session in the screening visit

Exclusion Criteria:

* Recent (\<30 days) or current participation in another clinical trial
* Women that are pregnant, nursing, or planning to become pregnant during the study period
* Current use of contraindicated/psychoactive medications or illicit drugs
* Lifetime use of classical psychedelics more than 20 times, or any time within the previous two months
* Consumption of \>5 cigarettes per day or \>20 alcoholic standard drinks per week
* Severe chronic or acute medical condition
* Hypertension (\>140/90 mmHg) or hypotension (\<85mmHg systolic)
* Current or lifetime major mental health disorder
* Personal or family (first-degree) history of a primary psychotic disorder

Primary outcomes:
measure: Change in changepoint task
timeFrame: three times (once on each of the three test days; interval between test days at least 7 days)
measure: Change in history bias task
timeFrame: three times (once on each of the three test days; interval between test days at least 7 days)
Secondary outcomes:
Other outcomes:
Locations:
city: Basel
country: Switzerland
facility: University Psychiatric Clinics Basel
Study officials:
affiliation: University Psychiatric Clinics Basel
name: Philipp Sterzer, Prof. Dr.
role: PRINCIPAL_INVESTIGATOR
References: