Greater empathy in MDMA users

Introduction

Carlyle and colleagues frame their study around MDMA's well-documented acute prosocial effects — increases in compassion, trust, generosity and empathy — and its capacity to attenuate responses to social threat and social exclusion. Earlier experimental work has shown that, acutely, MDMA preferentially enhances emotional empathy (the tendency to feel others' emotions) over cognitive empathy (the ability to infer others' mental states, sometimes called 'theory of mind'), and these effects are thought to involve serotonergic mechanisms and hormones such as oxytocin. At the same time, preclinical and imaging studies have raised concerns that heavy, chronic MDMA use may reduce 5-HT transporter markers, which could plausibly impair social functioning over the long term; however, much of that imaging literature has sampled exceptionally heavy users, and the causal direction of findings is uncertain. The current study set out to characterise whether repeated, predominantly low-level recreational MDMA use is associated with altered social functioning, focusing on empathy and sensitivity to social exclusion (social pain). Carlyle and colleagues targeted mild but regular MDMA users to better approximate doses likely to be used in therapeutic contexts and compared them with two control groups: poly-drug users who do not use MDMA, and alcohol-only users. They hypothesised that chronic MDMA use might impair empathy and increase sensitivity to social pain consistent with serotonergic dysfunction, although they also note alternative possibilities framed by recent evidence suggesting preserved or even enhanced empathy with repeated MDMA exposure.