When two hearts beat as one: Heart-rate synchrony in social anxiety disorder.

Individuals with social anxiety disorder (SAD) experience significant interpersonal impairment. However, little is known about the physiological processes that are associated with interpersonal dysfunction in the disorder. In the present study we examined heart-rate (HR) synchrony in SAD during "getting-acquainted" interactions between opposite-sex partners. Participants included 118 individuals who formed 59 dyads: 30 dyads that included one individual with SAD and one non-socially anxious (NSA) individual (SAD dyads) and 29 dyads that included two NSA individuals (control dyads). Dyads were randomly assigned to either a closeness-generating conversation or a small talk conversation. For closeness-generating conversations, we found that social anxiety was positively associated with HR synchrony in control dyads but negatively associated with HR synchrony in SAD dyads. These results remained when controlling for depressive symptoms and participants' movement. Our findings suggest that in more intimate social contexts, SAD may impair the ability to create HR synchrony between interlocuters and this can have negative relational consequences. Our findings are further discussed in the context of cognitive behavioral and interpersonal models of SAD, and clinical and research implications are delineated.