Cognitive dysfunction in bipolar disorder: between determinants and consequences

PhD ceremony: Ms. M.J. van der Werf-Eldering, 12.45 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Cognitive dysfunction in bipolar disorder: between determinants and consequences

Promotor(s): prof. W.A. Nolen, prof. A. Aleman

Faculty: Medical Sciences

Patients known with bipolar disorder can show cognitive dysfunction when experiencing mood symptoms, but also in absence of these symptoms (euthymic phase). This thesis gives an overview of the type and extent of cognitive dysfunction, the clinical relevant factors and the relationship with functional outcome. Cognitive dysfunction, especially in areas of speed and attention, is related to depressive symptoms, worse illness course, and worse occupational as well as psychosocial outcome. Changes in the stress system (HPA-axis) are related to both depression and cognitive dysfunction and could therefore play a role in the presence of cognitive disturbances in bipolar patients. However, we could not confirm the hypothesis that changes in the HPA-axis can explain the associations between depressive symptoms and cognition in bipolar patients. It is important to know a patients personal opinion about his own cognitive performance and the ability to evaluate his personal condition (the level of illness-insight). In bipolar patients complaints about cognitive dysfunction was not associated with objective cognitive dysfunction, however complaining was related to depressive symptoms. Moreover, cognitive functioning – besides emotional learning and the presence of lifetime psychotic features – contributed to better illness insight. In conclusion, besides striving for stabilizing mood symptoms, treatment of bipolar patients needs to take into account the possible presence of cognitive dysfunction. There is a need for (international) consensus about the optimal cognitive test battery, the interpretation of the test results, and how to proceed in case objective cognitive dysfunction is found.