Dampening versus amplification: Intrapersonal and interpersonal vocal affect dynamics during psychotherapy for depression

Objective: Major depressive disorder (MDD) is associated with ineffective affect regulation. Vocal data can shed light on communication and expression during psychotherapy and provide high-resolution data for the study of affective arousal dynamics. Computerized vocal analyses were used to examine the extent to which intrapersonal and interpersonal vocal-arousal dynamics were linked to session outcomes and whether a session’s dampening as compared to an amplification arousal trajectory would moderate this association. Method: Data from 30 clients treated for MDD by nine therapists were analyzed. A total of 9,324 vocal arousal data points were extracted from the working phases of 137 therapy sessions. The clients reported their well-being levels before and after each session on the Outcome Rating Scale. Results: Vocal-analysis revealed both intrapersonal regulation (towards one's baseline) and interpersonal regulation (towards the partner's arousal level). Only clients’ interpersonal regulation towards their therapist's arousal level was linked to better session outcomes. Notably, this positive link occurred more in sessions where the client's overall arousal decreased (dampening); no such link was observed when arousal increased (amplification). Conclusions: These results suggest that interpersonal (i.e., therapist-client) affect regulation may contribute to therapeutic change in sessions characterized by overall dampening in patients diagnosed with MDD.