Mechanisms of Change in Brief Treatments for Borderline Personality Disorder: a Protocol of a Randomized Controlled Trial

Background: Borderline personality disorder (BPD) is one of the most frequent, most debilitating and lethal mental conditions and is associated with a serious burden of disease. Treatment for patients with BPD involves structured psychotherapy, and may involve brief psychiatric treatment as first-line intervention. No controlled study has assessed the effectiveness of such brief intervention. Whereas most psychotherapy studies in patients with BPD focus on the effectiveness of the intervention, we still lack an understanding of how and why these effects are produced from a patient process perspective. It is therefore of utmost importance to study the treatment-underlying mechanisms of change. The present study plans to apply novel measurement methods for assessing change in two central psychobiological processes in BPD: emotion and socio-cognitive processing. The study uses theory-driven and ecologically valid experimental tasks, which take the patient's individual experience as the anchor, by integrating methodology from psychotherapy process and neurofunctional imagery research.

Methods: The aim of this two-arm, randomized controlled study is to test the effects (i.e., symptom reduction) and the underlying mechanisms of change associated with a brief psychiatric treatment (10 sessions over 4 months), compared with treatment as usual. Participants (N = 80 patients with BPD) undergo assessments at four points (intake, 2 months, discharge, and 12-month follow up). In addition to symptom measures, individuals undergo a 2-step assessment for the potential mechanisms of change (i.e., emotion and socio-cognitive processing): (1) behavioral and (2) (for a sub-sample) neurofunctional. We hypothesize that change in the mechanisms explains the treatment effects.

Discussion: This study uses an easy-to-implement treatment of BPD, and a sophisticated assessment procedure to demonstrate the critical role of psychobiological change in emotion and socio-cognitive processing in brief treatments. It will help increase the effectiveness of brief treatment for BPD and help diminish the societal burden of disease related to BPD, in these early stages of treatment. TRIAL REGISTRATION {2}: ClinicalTrials.gov: NCT03717818. Registered on 24 October 2018). Protocol version {3} number 2 from 9 February 2018.