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:
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?
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).
Amendment 1 (Approved October 22, 2024):
Diagnostic information obtained during intake, using the Structured Clinical Interview
for DSM-5 Syndrome Disorders (SCID-5-S), is used to verify inclusion criteria. Although
this was part of the original protocol, it has now been explicitly clarified in the
participant information material. Additionally, therapist-maintained logbooks documenting
deviations from standard treatment protocols (e.g., missed sessions or clinical
incidents) have been introduced to enhance contextual interpretation of the SCED data.
Amendment 2 (Approved January 23, 2025):
To increase the representativeness of the sample, the maximum number of participants has
been increased from 6 to 8. Furthermore, a qualitative component was added to the design.
After completing treatment, participants, their caregivers, and their therapists will be
invited to take part in semi-structured interviews to explore perceived treatment
processes and outcomes. These interviews aim to enrich interpretation of quantitative
findings and explore perspectives on symptom change, treatment satisfaction, and
contextual factors.
