RESUMEN
ABSTRACT: The pilot study investigated with a matched-subjects design whether nonverbal synchrony is a diagnostic feature for depression and whether it mediates between depression and postsession ratings of the interviewer behavior. The sample includes n = 15 patients with major depression and n = 15 healthy controls (aged 20-30 years, 40% female). We conducted structured diagnostic interviews for somatic complaints to standardize the recording setting, issue, and course of conversation. Body movements and facial expressions were coded automatically frame by frame using computer vision methods. Ratings of the interviewers' professional behavior and positive affect were assessed using questionnaires. Patients with depression showed less movement synchrony and less synchronous positive facial expressions. Only synchronous positive expressions mediated between depression and less perceived positive affect. We conclude that the applied methodology is well suited to examine nonverbal processes under naturalistic but widely standardized conditions and that depression affects the nonverbal communication in medical conversations.