MBT-early: a Single Case Experimental Design

Borderline personality disorder (BPD) is characterized by problems in emotion regulation, identity disturbances, and impaired interpersonal functioning. Because BPD may determine health and quality of life in long term, it is important to focus on early detection and early intervention to prevent worsening. In this study, the effectiveness of a new intervention, MBT-early, is investigated in adolescents with borderline personality problems through a single case experimental design (SCED). Existing studies into the efficacy of psychotherapeutic interventions for young people with a (subclinical) borderline personality disorder (BPD) show mixed results. An obvious explanation therefore lies in the heterogeneity of the samples studied, where the same intervention is investigated by young people with some characteristics of borderline personality problems in an early stage as by young people with significant borderline personality problems at a later stage. However, there is evidence that interventions should be targeted specifically at the stage of progression of the disorder ('staged care'). Interventions may be more effective when they correspond to the stage of disease progression. MBT-early is an intervention intended for young people in an early stage of BPD. The intervention not only addresses the characteristics of BPD, but generally aims to improve personality functioning. MBT-early focuses on strengthening the young person's mentalizing capacity and to increase epistemic trust (the openness to learn from others) in order to prevent developmental stagnation and chronic consequences of personality disfunctioning. Although there is evidence for the efficacy of MBT for adults and adolescents, MBT-early has not yet been studied in terms of effectiveness. This study sets out to investigate the effectiveness of MBT-early, using a Single Case Experimental Design. The investigators hypothesize that treating youngsters with early features of BPD with MBT-early results in reduction of features of personality problems and the most frequently occurring symptoms (depressive symptoms). Exploratively mechanisms of change are being explored.

Research questions:

1. What is the effectiveness of MBT-early in youth with early stage BPD? 1a) What effect does MBT-early have on the improvement of personality functioning? 1b) What effect does early MBT have on the degree of depressed mood?

2. What are the possible working mechanisms of MBT-early? 2a) Does the youth's mentalizing ability influence the improvement of personality functioning? 2b) Does epistemic trust affect the improvement of personality functioning?

Objective of the study: The primary objective is to study the effectiveness of MBT-early in terms of treatment outcome on personality functioning and depressive symptoms. As a second objective the investigators will exploratively study the presumed working mechanisms of the MBT-early intervention (mentalizing capacities and epistemic trust).