The Effect of LSD on Neural Synchrony, Prosocial Behavior, and Relationship Quality

The goal of this study is to assess the effects of LSD on neural synchrony, prosocial behavior, and relationship quality in healthy romantic couples.

Study Overview

• Status: Recruiting
• Conditions: Prosocial Behavior
• Intervention / Treatment: Drug: LSD; Drug: Ethanol

Detailed Description

Evidence is growing that psychedelic substances such as psilocybin, lysergic acid diethylamide (LSD) and ayahuasca could be a potential alternative treatment option for common and difficult to treat psychiatric conditions. One proposed mechanism that psychedelics target, which is a hallmark of seemingly all psychiatric disorders, are deficits in social cognitive abilities. However, the neural underpinnings of psychedelic induced alterations in prosocial behavior are currently unknown. The investigators hypothesize psychedelics increase such prosocial behaviors by increasing neural synchrony, which is the coupling of brain-to-brain activity across two or more people; it has been found to underlie social connection and various forms of shared prosocial behavior.

The current project will primarily assess whether LSD enhances neural synchrony between romantic partners. Second, the investigators will assess whether LSD enhances prosocial behavior between members of a dyad, thus replicating previous studies which assessed prosocial behavior within one individual at a time. The investigators will also assess the relationship between neural synchrony and outcome variables of the prosocial behaviour tasks. Lastly, it will be assessed whether LSD-induced changes in neural synchrony and/or prosocial behaviour affect persisting relationship quality. Oxytocin and cytokine concentrations, will also be quantified to investigate whether there is a relationship between these factors and changes in prosocial behaviour.

The study design will be conducted according to a double-blind, placebo-controlled, 2-way crossover design. Healthy participants (N=60) who are in a relationship (N=30 couples) will receive placebo and an oral dose of 50 µg of LSD. Between each condition, there will be a minimum of 14 days washout. This leads to a total study duration of minimally four weeks, for a participant to go through the medical examination and both drug conditions.

• Study Type: Interventional
• Enrollment (Anticipated): 60
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Natasha Mason, PhD; Phone Number: +31 43 3881382; Email: natasha.mason@maastrichtuniversity.nl

Study Locations

• Netherlands
  • Maastricht, Netherlands
    • Recruiting
    • Maastricht University
    • Contact: Natasha Mason, PhD; Email: natasha.mason@maastrichtuniversity.nl

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Written Informed Consent
• Understanding the procedures and the risks associated with the study.
• Age between 18 and 35 years old.
• Being in a steady relationship for at least 6 months.
• Proficient knowledge of the English language
• Previous experience with at least one psychedelic drug (psilocybin, LSD, mescaline, Ayahuasca, DMT, 5-MeO-DMT), but not within the past 3 months
• Absence of any major medical condition as determined by medical examination and laboratory analysis
• Absence of any major psychological condition as determined by medical examination
• Free from psychotropic medication
• Participants must be willing to refrain from taking illicit psychoactive substances during the study.
• 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.
• Participants must be willing not to drive a traffic vehicle or to operate machines within 24 h after substance administration.
• Normal weight, body mass index (weight/height2) between 18 and 28 kg/m2

Exclusion Criteria:

• History of drug addiction (determined by the medical questionnaire, drug questionnaire and medical examination)
• Previous experience of serious side effects to psychedelic drugs (anxiety or panic attacks)
• Pregnancy or lactation
• Hypertension (diastolic > 90 mmHg; systolic > 140 mmHg)
• Current or history of psychiatric disorder (determined by the medical questionnaire and medical examination)
• Psychotic disorder in first-degree relatives
• Any chronic or acute medical condition
• History of cardiac dysfunctions (arrhythmia, ischemic heart disease,…)
• For women: no use of a reliable contraceptive
• Tobacco smoking (>20 per day)
• Excessive drinking (>20 alcoholic consumptions per week)
• Experience with a full dose of a psychedelic within the last three months
• Current use of SSRI medication

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: LSD condition; 60 participants will receive LSD.	Drug: LSD; Single dose of LSD (50 µg) will be administered in a small amount of alcohol (ethanol, 2ml/95% Vol.) orally.; Other Names: lysergic acid diethylamide
Placebo Comparator: Ethanol condition; 60 participants will receive placebo.	Drug: Ethanol; Identical ampules containing pure ethanol without the investigational product will be used (1mL ethanol, 95% Vol.).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neural synchrony	Quantification of neural synchrony between members of a couple utilizing previously validated naturalistic interaction paradigms, including a motor cooperation task, empathy giving task, and affective touch and eye contact paradigm, will be employed. Resting state EEG will be used as a control.	On the acute dosing test day, 1.5-2 hours after substance administration

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Empathy	Cognitive and emotional empathy will be assessed via the empathy giving task (EGT) and the multifaceted empathy test (MET).	On the acute dosing test day, 2 hours (EGT) and 3 hours (MET) after substance administration
Self-other distinction	The degree of self-other merging will be assessed using synchronous multisensory stimulation (SMS), and responses on the inclusion of other in the self scale (OIS).	On the acute dosing day, 2.5 hours (SMS) after substance administration. The OIS will be administered repeatedly at baseline (-0.5 hours), 2 hours, 3 hours, 4.5 hours, and 7 hours after substance administration, and at 2 days follow up.
Prosocial behavior	Prosocial behavior will be assessed via participants' response rate on the prosocial learning task (PLT), and the amount of effort for other individual in the prosocial effort task (PET).	On the acute dosing day, 6 hours after substance administration. The PET will also be administered at 2 days follow-up.
Social influence processing	Social influence processing will be assessed via participants' degree of rating adjustment after feedback in the social influence paradigm (SIP).	On the acute dosing day, 3 hours after substance administration
Trust	The trust game for couples (TGC) will assess participants' willingness to invest personal resources in pro-relationship attitudes.	On the acute dosing day, 6.5 hours after substance administration
Creativity	Creativity will be assessed by the semantic distance in the chain free association (CFO) and the divergent association tasks (DAT), and also by the ability to separate old and new information in the pattern separation task (PST).	On the acute dosing day, 5.5 hours (CFO, PST) after substance administration. The DAT will be administered at 2 days follow-up.
Sociality	Sociality will be measured by the social reward questionnaire (SRQ) and the visual analogue scales that measure feelings of social behavior (VAS-S).	On the acute dosing day, SRQ will be administered at 4.5 hours after substance administration, while the VAS-S will be administered at baseline (-0.5 hours), at 1, 2, 3, 4, 5, 6, and 7 hours after substance administration.
Conflict resolution	The couples conflict resolution (CR) task will measure the duration of positive and negative behavior of members of a couple via video recordings of couples' interactions.	At 2 days follow-up.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Relationship quality	Relationship quality will be measured via subjective reports on a number of scales: the couples satisfaction index (CSI), the perceived partners responsiveness scale (PPRS), the experiences in close relationship scale (ECR), and the interpersonal reactivity index for couples (IRI-C).	At baseline, 2 days follow-up (CSI) and at 4 days follow-up (CSI, PPRS, ECR, IRI-C).
Sexual function	Sexual function will be measured via subjective reports on a number of scales: the global measure of sexual satisfaction (GMSEX), the female sexual function index (FSFI), and the international index of erectile function (IIEF).	At baseline, 2 days follow-up (GMSEX), and at 4 days follow-up (GMSEX, FSFI/IIEF).
Well-being	Well-being will be measured via subjective reports on the satisfaction with life scale (SWLS).	On the acute dosing day, at baseline (-0.5 hours) and at 7 hours after substance administration, at the 2 day follow-up, and at the 4 day follow-up.
Subjective drug effects	Subjective drug effects will be measured via subjective reports on the altered states of consciousness rating scale (5D-ASC), and on the ego dissolution inventory (EDI).	On the acute dosing day, 7 hours after substance administration.
Real-time social behavior	Real-time social behavior will be assessed via subjective reports on experience sampling questions (ESQ) in the Ethica app.	Daily up until 3 days after the acute dosing day.
LSD concentrations	Blood samples will be collected to measure LSD concentrations	Acute dosing day:baseline (-0.5 hour), at 1.5, 2.5, 3.5, 5, and at 7 hours.
Oxytocin concentrations	Blood samples will be collected to measure oxytocin	Acute dosing day:baseline (-0.5 hour), at 1.5, 2.5, 3.5, and 4.5 hours after substance administration.
Metabolomics concentration	Blood samples will be collected to measure metabolomics	Acute dosing day:baseline (-0.5 hour), at 1.5 and 7 hours after substance administration.
Inflammatory cytokines	Blood samples will be collected to measure inflammatory cytokine levels	Acute dosing day:baseline (-0.5 hour), at 1.5 hours and 2 days after substance administration.
Aftercare	Any lasting negative effects of the drug will be assessed via a visual analogue scale (VAS).	At the end of the 2 day followup

Collaborators and Investigators

• Sponsor: Maastricht University
• Investigators: Principal Investigator: Johannes G Ramaekers, PhD, Maastricht University

Study record dates

Study Major Dates

• Study Start (Anticipated): January 1, 2023
• Primary Completion (Anticipated): January 1, 2024
• Study Completion (Anticipated): January 1, 2024

Study Registration Dates

• First Submitted: November 30, 2022
• First Submitted That Met QC Criteria: December 20, 2022
• First Posted (Estimate): January 4, 2023

Study Record Updates

• Last Update Posted (Estimate): January 4, 2023
• Last Update Submitted That Met QC Criteria: December 20, 2022
• Last Verified: November 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Anti-Infective Agents, Local; Anti-Infective Agents; Central Nervous System Depressants; Psychotropic Drugs; Serotonin Agents; Serotonin Receptor Agonists; Serotonin Antagonists; Hallucinogens; Ethanol; Lysergic Acid Diethylamide
• Other Study ID Numbers: NL80435.068.22

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No