(PS8-C66) Predicting Therapeutic Alliance Trajectories in Dialectical Behavioral Therapy for Borderline Personality Disorder: Examining Client and Treatment Factors

Research has highlighted the crucial role of therapeutic alliance in psychotherapy, especially in treating Borderline Personality Disorder (BPD), which is characterized by pervasive interpersonal issues. Recent studies have emphasized the importance of longitudinal exploration of therapeutic alliance in Dialectical Behavioral Therapy (DBT) for BPD (Guimond et al., 2022; Bedics et al., 2015). However, there is limited knowledge about the client and treatment factors that influence therapeutic alliance trajectories in DBT. In this study, we will investigate whether client characteristics, such as symptom severity, interpersonal functioning, and treatment expectancy, predicted both client- and therapist-rated alliance trajectories, and if the length of DBT (6 versus 12 months) affected these trajectories. Using growth curve modeling, we will analyze data from a previously published randomized controlled trial (McMain et al., 2022), which recruited 240 suicidal and/or self-injurious individuals with a diagnosis of BPD. Clients completed measures of BPD symptoms, interpersonal functioning, and treatment expectancy at baseline and every 3 months, in addition to a measure of working alliance completed by both clients and therapists after 1, 2, 3, and 4 weeks of therapy and at 3 and 6 months. Our study seeks to provide a more nuanced understanding of the therapeutic alliance trajectories in DBT for BPD and identify the client and treatment factors that hinder the formation of a strong therapeutic alliance, ultimately promoting a positive therapeutic experience for individuals with BPD.