Nonverbal synchrony predicts premature termination of psychotherapy for social anxiety disorder.

Premature termination is a problem in psychotherapy. In addition to the examination of demographic and clinical variables as predictors of dropout, research indicates the importance of dyadic variables. Nonverbal synchrony (e.g., movement synchrony) operationalizes the coordination of patient and therapist and is a promising candidate for predicting premature termination. This secondary data analysis included data on patients with social anxiety disorder ( = 267) that were treated with > 20 sessions of cognitive-behavioral therapy or psychodynamic therapy. Therapy outcome was measured by the Inventory of Interpersonal Problems and the Beck Depression Inventory. Individual movements in the third session were assessed by motion energy analysis. Movement synchrony was identified with a windowed cross-lagged correlation and peak-picking algorithm. We performed logistic regressions and mixed effects Cox regressions to investigate synchrony as a predictor of premature termination. Therapist-patient dyads that included a patient who terminated psychotherapy prematurely had significantly lower movement synchrony at the beginning of therapy than patients who completed therapy. Gender-matching and therapeutic approach had a (marginally) significant effect in moderating the relationship. Therefore, low movement synchrony in early therapy sessions may contain clues to premature termination and reflect a mismatch between the patient and therapist or problems in the therapeutic alliance. (PsycINFO Database Record (c) 2019 APA, all rights reserved).