Aim: Borderline personality disorder (BPD) is characterized by a pattern of instability in interpersonal relationships. Therefore, the investigation of social cognition is of compelling interest for the understanding of BPD. One important aspect of social cognition is theory of mind (ToM), which describes the ability to understand others' mental states, such as beliefs, desires and intentions. The aim of the present study was to further investigate ToM in BPD patients.
Methods: The Reading the Mind in the Eyes Test was assessed in 31 BPD patients and 27 healthy controls. In addition, the test was complemented by a response confidence rating.
Results: BPD patients and healthy controls did not differ in their mind-reading ability with respect to accuracy, but patients were significantly more often highly confident in their decisions than controls.
Conclusions: Overconfidence might contribute to the severe difficulties in interpersonal relationships often observed in BPD patients.