Predicting Heterogenous Effects of Alliance Ruptures in Depression: Implications for Personalized Psychotherapy Based on Interpersonal Functioning

Background: Alliance ruptures are common events in psychotherapy and have been linked to poorer outcomes when unresolved. However, little is known about how individual differences, particularly interpersonal problems, shape the impact of ruptures on treatment response in depression. This study examined the within- and between-patient effects of withdrawal (WR) and confrontation ruptures (CR) on depressive symptom severity and tested whether interpersonal problems of agency and communion moderate these effects. Methods: We conducted a secondary analysis of data from a randomized controlled trial comparing two forms of supportive therapy for major depressive disorder (N = 100). Ruptures were assessed with the observer-rated Rupture Resolution Rating System across six therapy sessions. Interpersonal problems were measured at baseline with the Inventory of Interpersonal Problems. Depressive symptom severity was assessed session-by-session using the Hamilton Depression Rating Scale. Multilevel models disaggregated within- and between-patient effects and tested moderation by interpersonal problems. Results: WRs showed a significant within-patient effect: sessions with higher-than-average WR intensity were associated with greater depression severity. CRs showed no significant within- or between-patient effects. Interpersonal problems moderated rupture effects: low agency amplified the between-patient effect of WR, whereas high communion amplified the within-patient effects of both WR and CR on depression severity. Conclusions: Findings suggest that the impact of ruptures on outcome in depression is heterogeneous and shaped by patients' interpersonal problems. Personalizing therapy according to patients' interpersonal profiles may enhance treatment outcomes. Future research should examine rupture–repair cycles and incorporate multiple perspectives on alliance processes.