Effects of patient–therapist interpersonal complementarity on alliance and outcome in cognitive–behavioral therapies for depression: Moving toward interpersonal responsiveness.

This study analyzed patient-therapist in-session interpersonal complementarity effects on the therapeutic alliance and depression severity during the initial and working phase of cognitive-behavioral therapy for depression. It also explored whether patients' interpersonal problems moderate those complementarity effects. We drew on a sample of 90 dyads derived from a randomized controlled trial of two cognitive-behavioral therapies for depression. Using an observer-based measure, we assessed patients' and therapists' interpersonal behavior in Sessions 1, 5, 9, and 13 and computed their complementarity regarding interpersonal affiliation (i.e., correspondence) and dominance (i.e., reciprocity). Patients completed measures of interpersonal problems at baseline and session-by-session measures of depression severity and quality of the therapeutic alliance. Response surface analyses based on polynomial regressions showed that patient-therapist complementarity in higher affiliative behaviors was associated with a stronger alliance. Interpersonal problems regarding agency moderated the complementarity effects of the dominance dimensions on depression severity. Overly dominant patients benefited more from a nonreciprocal relationship in the dominance dimension, whereas submissive patients benefited more from complementarity in that dimension. Furthermore, interpersonal problems of communion significantly moderated the effects of complementarity in affiliative behaviors on both the alliance and outcome. These results suggest the relevance of both interpersonal correspondence and reciprocity for the psychotherapy process, informing clinical practice in terms of interpersonal responsiveness. The moderation effects of interpersonal problems provide preliminary evidence, which should be replicated in future research, to determine relevant markers indicating for whom a complementary approach would be beneficial in cognitive therapy for depression. (PsycInfo Database Record (c) 2021 APA, all rights reserved).