No evidence that MDMA-induced enhancement of emotional empathy is related to peripheral oxytocin levels or 5-HT1a receptor activation

PLoS One. 2014 Jun 27;9(6):e100719. doi: 10.1371/journal.pone.0100719. eCollection 2014.

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.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Emotions / drug effects
  • Empathy / drug effects
  • Female
  • Humans
  • Interpersonal Relations
  • Male
  • N-Methyl-3,4-methylenedioxyamphetamine / blood
  • N-Methyl-3,4-methylenedioxyamphetamine / pharmacology*
  • N-Methyl-3,4-methylenedioxyamphetamine / therapeutic use
  • Oxytocin / blood
  • Oxytocin / pharmacology
  • Oxytocin / therapeutic use*
  • Pindolol / blood
  • Pindolol / pharmacology
  • Pindolol / therapeutic use
  • Placebo Effect
  • Receptor, Serotonin, 5-HT1A / metabolism*
  • Substance-Related Disorders / drug therapy*
  • Surveys and Questionnaires
  • Young Adult

Substances

  • Receptor, Serotonin, 5-HT1A
  • Oxytocin
  • Pindolol
  • N-Methyl-3,4-methylenedioxyamphetamine

Associated data

  • NTR/NTR2636

Grants and funding

This work was supported by the Netherlands Organization for Scientific Research (NWO), Grant number: 400-07-2013, awarded to JR and KK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.