THE RELATIONSHIP BETWEEN AGREEABLENESS AND THE DEVELOPMENT OF THE WORKING ALLIANCE IN PATIENTS WITH BORDERLINE PERSONALITY DISORDER

The working alliance between therapist and patient is an important component of effective interventions for borderline personality disorder (BPD). The current study examines whether client personality affects the development of the working alliance during the treatment of BPD, and whether this influences treatment effectiveness. Data was based on 87 patients with BPD who were participants in a randomized controlled trial comparing Dialectical Behavior Therapy (DBT) and general psychiatric management. Higher levels of trait Agreeableness were associated with steeper increases in working alliance throughout treatment, but only in the DBT condition. Increases in working alliance were in turn associated with better clinical outcomes. Mediation models revealed a significant indirect path from Agreeableness to better clinical outcomes, mediated through larger improvements in working alliance over time. These results highlight the role that patient personality can play during the therapeutic process, with a specific focus on the importance of Agreeableness for alliance development.