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.

Inclusion Criteria:Written Informed ConsentUnderstanding 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 languagePrevious experience with at least one psychedelic drug (psilocybin, LSD, mescaline, Ayahuasca, DMT, 5-MeO-DMT), but not within the past 3 monthsAbsence of any major medical condition as determined by medical examination and laboratory analysisAbsence of any major psychological condition as determined by medical examinationFree from psychotropic medicationParticipants 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/m2Exclusion 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 lactationHypertension (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 relativesAny chronic or acute medical conditionHistory of cardiac dysfunctions (arrhythmia, ischemic heart disease,…)For women: no use of a reliable contraceptiveTobacco smoking (>20 per day)Excessive drinking (>20 alcoholic consumptions per week)Experience with a full dose of a psychedelic within the last three monthsCurrent use of SSRI medication