Therapeutic alliance dimensions and treatment outcome in two psychotherapeutic approaches for adolescents with borderline personality disorder

Abstract Background The therapeutic alliance is a well-established predictor of treatment outcomes across age groups, mental disorders, and psychotherapeutic modalities. However, alliance is a multifaceted construct, and its specific dimensions, as well as their relevance across different treatment approaches, have rarely been examined in adolescents. Methods This study investigated the relationship between therapeutic alliance and treatment outcomes in a sample of treatment-seeking adolescents ( N = 57, mean age = 15.9 (SD = 1.3) years) with subthreshold or full borderline personality disorder (BPD). Participants received either dialectical behavior therapy for adolescents (DBT-A) or adolescent identity treatment (AIT). The therapeutic alliance was assessed using Bordin’s model, comprising the dimensions of task, goal, and bond. Results Early alliance was not uniformly related to outcome across treatments. While global alliance predicted improvement in personality functioning in AIT, it was not significantly associated with outcomes in DBT-A. At the dimensional level, task agreement appeared most relevant within DBT-A, whereas emotional bond was positively associated with psychosocial functioning in AIT. Exploratory multigroup comparisons provided strongest support for a treatment-specific role of emotional bond in AIT. Conclusion The alliance–outcome association was not uniform and appeared to vary across treatment approaches and alliance dimensions. Findings suggest that emotional bond may be particularly relevant in AIT, while task agreement may play a more prominent role within DBT-A, although the latter effect was not accompanied by significant between-treatment differences. Trial registration clinicaltrials.gov (NCT02518906; registration date: 10th of August 2015).