PhD defence M.L. (Maaike) Smits

Dissertation in short:

This thesis presents the results of a multicenter RCT that aimed to investigate the differential (cost)-effectiveness of two mentalization-based treatment (MBT) programs with markedly different intensity, for clients with borderline personality disorder (BPD).

BPD is a severe mental disorder characterized by a pervasive pattern of emotional instability, impulsivity, and dysfunctional relationships. From a mentalizing approach, BPD is understood as resulting from mentalizing impairments. Mentalizing is defined as the capacity to understand oneself, others, and relationships in terms of mental states, such as feelings, needs, beliefs, and desires. We all mentalize, and mentalizing processes ‘go offline’ for everyone at a certain point when arousal increases. In the mentalizing approach, it is hypothesized that the ability to mentalize in BPD clients — specifically in the context of attachment relationships — is more likely to collapse, resulting from the hypersensitivity of the attachment system resulting in arousal mounting more quickly. In addition, it is more difficult for BPD patients to recover from a loss of mentalizing. MBT explicitly focuses on improving
mentalizing capacities as a fundamental capacity, and by that means addresses a broad range of symptoms characteristic of BPD pathology.