Executive dysfunction in bipolar disorder and borderline personality disorder.

OBJECTIVE: The boundary between bipolar disorder (BD) and borderline personality disorder is a controversial one. Despite the importance of the topic, few studies have directly compared these patient groups. The aim of the study was to compare the executive functioning profile of BD and BPD patients.

METHOD: Executive functioning (sustained attention, problem-solving, planning, strategy formation, cognitive flexibility and working memory) was assessed in BD (n=30) and BPD outpatients (n=32) using a computerized assessment battery (Cambridge Neuropsychological Test Automated Battery, CANTAB). The groups were compared to one another as well as to healthy controls.

RESULTS: BD patients showed deficits in strategy formation and in planning (indicated by longer execution time in the ToL task) in comparison to BPD patients and healthy controls. BPD patients showed deficits in planning (short deliberation time in the ToL task) in comparison to BD patients and in comparison to healthy controls. In comparison to healthy controls, BPD patients displayed deficits in problem-solving.

CONCLUSIONS: Differences in executive dysfunction between BD and BPD patients suggest that this cognitive dimension may be relevant for the clarification of the boundary between the disorders.