title: No evidence that MDMA-induced enhancement of emotional empathy is related to peripheral oxytocin levels or 5-HT1a receptor activation.
abstract: The present study aimed at investigating the effect of MDMA on measures of empathy and social interaction, and the roles of oxytocin and the 5-HT1A receptor in these effects. The design was placebo-controlled within-subject with 4 treatment conditions: MDMA (75 mg), with or without pindolol (20 mg), oxytocin nasal spray (40 IU+16 IU) or placebo. Participants were 20 healthy poly-drug MDMA users, aged between 18-26 years. Cognitive and emotional empathy were assessed by means of the Reading the Mind in the Eyes Test and the Multifaceted Empathy Test. Social interaction, defined as trust and reciprocity, was assessed by means of a Trust Game and a Social Ball Tossing Game. Results showed that MDMA selectively affected emotional empathy and left cognitive empathy, trust and reciprocity unaffected. When combined with pindolol, these effects remained unchanged. Oxytocin did not affect measures of empathy and social interaction. Changes in emotional empathy were not related to oxytocin plasma levels. It was concluded that MDMA (75 mg) selectively enhances emotional empathy in humans. While the underlying neurobiological mechanism is still unknown, it is suggested that peripheral oxytocin does not seem to be the main actor in this; potential candidates are the serotonin 2A and the vasopressin 1A receptors. Trial registration: MDMA & PSB NTR 2636.
authors: Dept. of Neuropsychology & Psychopharmacology, Fac. of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands.
authors: Kim P C
authors: KP
authors: Kuypers
authors: IMIM- Hospital del Mar- Research institute, Human Pharmacology & Clinical Neurosciences Research Group, Barcelona, Spain.
authors: Rafael
authors: R
authors: de la Torre
authors: IMIM- Hospital del Mar- Research institute, Human Pharmacology & Clinical Neurosciences Research Group, Barcelona, Spain.
authors: Magi
authors: M
authors: Farre
authors: IMIM- Hospital del Mar- Research institute, Human Pharmacology & Clinical Neurosciences Research Group, Barcelona, Spain.
authors: Samanta
authors: S
authors: Yubero-Lahoz
authors: Cluster of Excellence Languages of Emotion, Freie Universität, Berlin, Germany.
authors: Isabel
authors: I
authors: Dziobek
authors: Center for Adaptive Rationality (ARC), Max-Planck-Institute for Human Development, Berlin, Germany.
authors: Wouter
authors: W
authors: Van den Bos
authors: Dept. of Neuropsychology & Psychopharmacology, Fac. of Psychology & Neuroscience, Maastricht University, Maastricht, the Netherlands.
authors: Johannes G
authors: JG
authors: Ramaekers
mesh_terms: D000293:Adolescent; D000328:Adult; D004644:Emotions / Q000187:drug effects; D004645:Empathy / Q000187:drug effects; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000097:blood / Q000494:pharmacology* / Q000627:therapeutic use; D010121:Oxytocin / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D010869:Pindolol / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D015990:Placebo Effect; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D019966:Substance-Related Disorders / Q000188:drug therapy*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D044282:Receptor, Serotonin, 5-HT1A; D010121:Oxytocin; D010869:Pindolol; D018817:N-Methyl-3,4-methylenedioxyamphetamine