Abstract
Borderline personality disorder (BPD) is characterized by severe interpersonal dysfunction with problems in social cognition, empathy and social approach. Although the neuropeptide oxytocin is known to regulate complex social cognition and behavior in healthy individuals and clinical populations, there is still a lack of evidence for a potential beneficial effect of oxytocin administration on social cognition and social approach in BPD. Fifty-one women with BPD and 51 matched healthy controls were randomized to a double-blind, placebo-controlled, between-subject experimental trial. We administered a single dose of 24 IU oxytocin or placebo intranasally prior to a standardized task measuring affective and cognitive empathy and approach motivation. All participants were free of hormonal contraception and tested in the mid-luteal phase of their menstrual cycle. In the placebo condition, patients with BPD showed reduced cognitive and affective empathy, and less approach behavior motivation than healthy controls. Intranasal oxytocin significantly increased affective empathy and approach motivation in both BPD patients and healthy controls compared to placebo. More importantly, oxytocin administration led to similar scores between BPD and healthy controls. These findings provide the first evidence for a beneficial effect of oxytocin on deficits in affective empathy and approach motivation of BPD. Our results indicate a beneficial effect of a single dose of oxytocin on affective empathy and approach motivation in women with BPD adapting their level of social functioning to healthy controls. Future clinical trials will need to investigate the long-term effects and effectiveness of oxytocin as an add-on treatment for social impairments in BPD.