Oxytocin receptor gene variations and socio-emotional effects of MDMA: A pooled analysis of controlled studies in healthy subjects

This pooled double-blind, placebo-controlled analysis (n=132) appraised oxytocin receptor (OXTR) gene variations such as single-nucleotide polymorphisms (SNPs) and their influence on socio-emotional effects of MDMA in healthy participants. The study found evidence that OXTR gene variations, which are shown to contribute towards prosociality and moral cognition, may modulate characteristics of the prosocial subjective effects of MDMA in human subjects. However, OXTR SNPs did not moderate the overall subjective response to MDMA (any drug effect) or sentiments that correlate to “closeness to others”.

Abstracts

“Methylenedioxymethamphetamine (MDMA) increases oxytocin, empathy, and prosociality. Oxytocin plays a critical role in emotion processing and social behavior and has been shown to mediate the prosocial effects of MDMA in animals. Genetic variants, such as single-nucleotide polymorphisms (SNPs), of the oxytocin receptor (OXTR) may influence the emotional and social effects of MDMA in humans. The effects of common genetic variants of the OXTR (rs53576, rs1042778, and rs2254298 SNPs) on the emotional, empathogenic, and prosocial effects of MDMA were characterized in up to 132 healthy subjects in a pooled analysis of eight double-blind, placebo-controlled studies. In a subset of 53 subjects, MDMA produced significantly greater feelings of trust in rs1042778 TT genotypes compared with G allele carriers. The rs53576 and rs225498 SNPs did not moderate the subjective effects of MDMA in up to 132 subjects. None of the SNPs moderated MDMA-induced impairments in negative facial emotion recognition or enhancements in emotional empathy in the Multifaceted Empathy Test in 69 subjects. MDMA significantly increased plasma oxytocin concentrations. MDMA and oxytocin concentrations did not differ between OXTR gene variants. The present results provide preliminary evidence that OXTR gene variations may modulate aspects of the prosocial subjective effects of MDMA in humans. However, interpretation should be cautious due to the small sample size. Additionally, OXTR SNPs did not moderate the subjective overall effect of MDMA (any drug effect) or feelings of “closeness to others”.“

Authors: Patrick Vizeli & Matthias E. Liechti