Exploring nonverbal synchrony in borderline personality disorder: A double-blind placebo-controlled study using oxytocin.

Intranasal oxytocin (inOT) attenuated nonverbal synchrony - a proxy for relationship quality - in patients with borderline personality disorder (BPD), while it increased nonverbal synchrony in healthy controls (CTL). Available models (rejection sensitivity; social salience) suggest that inOT may alter the way patients with BPD assess social situations, and this alteration is expressed by changes in nonverbal coordination. Patients with BPD display low levels of synchrony which are even below expected pseudosynchrony based on chance. The association between self-reported childhood trauma and lower synchrony in BPD was most evident for patient's imitative behaviour: Under inOT, patients with high scores of childhood trauma refrained from imitating their interview partners. Study limitations include small sample sizes and limited data on the psychological impact of the clinical interviews.