Effects of MDMA and Intranasal Oxytocin on Social and Emotional Processing

Abstract

MDMA (±3,4-methylenedioxymethamphetamine, 'ecstasy') is used recreationally, reportedly because it increases feelings of empathy, sociability, and interpersonal closeness. One line of evidence suggests that MDMA produces these effects by releasing oxytocin, a peptide involved in social bonding. In the current study, we investigated the acute effects of MDMA and oxytocin on social and emotional processing in healthy human volunteers. MDMA users (N ¼ 65) participated in a 4-session, within-between-subjects study in which they received oral MDMA (0.75, 1.5 mg/kg), intranasal oxytocin (20 or 40 IU), or placebo under double-blind conditions. The primary outcomes included measures of emotion recognition and sociability (desire to be with others). Cardiovascular and subjective effects were also assessed. As expected, MDMA dose-dependently increased heart rate and blood pressure and feelings of euphoria (eg, 'High' and 'Like Drug'). On measures of social function, MDMA impaired recognition of angry and fearful facial expressions, and the larger dose (1.5 mg/kg) increased desire to be with others, compared with placebo. Oxytocin produced small but significant increases in feelings of sociability and enhanced recognition of sad facial expressions. Additionally, responses to oxytocin were related to responses to MDMA with subjects on two subjective measures of sociability. Thus, MDMA increased euphoria and feelings of sociability, perhaps by reducing sensitivity to subtle signs of negative emotions in others. The present findings provide only limited support for the idea that oxytocin produces the prosocial effects of MDMA.

Amphetamine-related drugs neurotoxicity in humans and in experimental animals: Main mechanisms

“…According to his autobiography and interviews, in 1977 Shulgin introduced MDMA to Leo Zeff, a retired psychologist from Oakland (CA, USA), who was so impressed by the effects of MDMA that he decided to come out of retirement, and began to introduce MDMA to other psychotherapists across the USA (Benzenhöfer and Passie, 2010). The appeal of MDMA that has led to its use in psychotherapy is chiefly due to the particular profile of Page 11 of 82 A c c e p t e d M a n u s c r i p t 10 action of this substance, which includes amphetamine-like stimulant effects together with feelings of increased emotional sensitivity and closeness to other individuals (Kirkpatrick et al, 2014).…”

LSD acutely impairs fear recognition and enhances emotional empathy and sociality

“…In contrast to the psychedelics LSD and psilocybin, MDMA is considered an empathogen (entactogen) that mainly enhances positive feelings, empathy, and prosociality (Hysek et al, 2014a;Kirkpatrick et al, 2014) while having few hallucinogen-like effects. Additionally, MDMA has been shown to positively alter emotion processing (Bedi et al, 2010;Hysek et al, 2012Hysek et al, ,2014aKirkpatrick et al, 2012Kirkpatrick et al, ,2014Schmid et al, 2014). These acute effects of MDMA on emotion processing and social behavior may be beneficial during psychotherapy in the absence of a full psychedelic peak experience.…”

Effects of methylphenidate and MDMA on appraisal of erotic stimuli and intimate relationships

“…For example, MDMA has been shown to acutely alter related components of social cognition including recognition of facial emotions (Bedi et al, 2010;Hysek et al, 2012a;Hysek et al, 2013;Hysek et al, 2014;Kirkpatrick et al, 2014) and emotional empathy (Hysek et al, 2013;Kuypers et al, 2014;Schmid et al, 2014). Additionally, changes in 5-HT levels may influence cognitions sustaining intimate relationships.…”

“…We therefore evaluated the effect of a 5-HT releaser (MDMA) and a DA and NA reuptake inhibitor (methylphenidate) on cognitive appraisal of intimate relationships. We hypothesized that MDMA, but not methylphenidate, would increase ratings of intimacy and romance in the Couples Appraisal Task (CAT) (Bilderbeck et al, 2011;Bilderbeck et al, 2014) parallel to its 5-HT enhancing, empathogenic and prosocial effects (Hysek et al, 2013;Kirkpatrick et al, 2014).…”