Diagnostic Features of Nonverbal Synchrony in Psychotherapy: Comparing Depression and Anxiety

It has repeatedly been shown that interacting persons synchronize their affective, physiological, verbal and nonverbal responses, especially when they are engaged in positive interaction. Nonverbal synchrony (assessed by automated measurement of videotaped movements) is a new concept in psychotherapy research, which has been associated with alliance, selfefficacy and outcome. However, there is a lack of knowledge regarding diagnostic differences in nonverbal synchrony. In this study, we investigated diagnosis and movement quantity as predictors of nonverbal synchrony. The naturalistic analysis sample consisted of 173 videotaped sessions of patients with a depressive disorder (N = 68) or an anxiety disorder (N = 25), who were treated with cognitive behavioral therapy at an outpatient clinic in southwest Germany. Therapy videos were routinely collected and nonverbal synchrony was computed using motion energy analysis (MEA). Using multilevel modeling, we first investigated the influence of diagnosis and time of assessment on patient and therapist movement quantity. Second, we predicted nonverbal synchrony by diagnosis and time of assessment, while controlling for patient movement quantity. We found a lower quantity of movement in depressive than in anxious patients. At the beginning of therapy, nonverbal synchrony was lower in dyads with depressive patients, even when controlling for patient movement quantity. At the end of therapy, patients with depression and anxiety no longer differed as nonverbal synchrony increased in depression and decreased in anxiety during the course of therapy. Nonverbal synchrony provides information beyond psychomotor retardation and is discussed with regard to patients' range of affect and attention focus.