The authors of this paper do not have any commercial associations that might pose a conflict of interest in connection with this manuscript.
Neurocognitive profiles in bipolar I and bipolar II disorder: differences in pattern and magnitude of dysfunction
Article first published online: 6 FEB 2008
© 2008 Blackwell Munksgaard
Volume 10, Issue 2, pages 245–255, March 2008
How to Cite
Simonsen, C., Sundet, K., Vaskinn, A., Birkenaes, A. B., Engh, J. A., Hansen, C. F., Jónsdóttir, H., Ringen, P. A., Opjordsmoen, S., Friis, S. and Andreassen, O. A. (2008), Neurocognitive profiles in bipolar I and bipolar II disorder: differences in pattern and magnitude of dysfunction. Bipolar Disorders, 10: 245–255. doi: 10.1111/j.1399-5618.2007.00492.x
- Issue published online: 6 FEB 2008
- Article first published online: 6 FEB 2008
- Received 22 May 2006, revised and accepted for publication 19 January 2007
- bipolar disorder;
- bipolar I;
- bipolar II;
- executive function;
- neurocognitive function
Objectives: Studies on neurocognitive functioning in bipolar disorder, reporting deficits in memory, attention, and executive functioning, have primarily focused on bipolar I disorder. The aim of this study was to examine whether patients with bipolar I and bipolar II disorder have different neurocognitive profiles.
Methods: Forty-two patients with bipolar I disorder, 31 patients with bipolar II and 124 healthy controls, from a large ongoing study on psychotic disorders, were included. Neurocognitive function was measured with a comprehensive neuropsychological test battery.
Results: The bipolar I group performed significantly poorer than the healthy control group and the bipolar II group on all measures of memory. Compared with the control group, the bipolar I group also had significantly reduced performance on most measures of attention and executive functioning, while the bipolar II group only had a significantly reduced performance on a subset of these measures. On average, 24% of the bipolar I group had clinically significant cognitive impairment (≤1.5 SD below the control group mean) across measures, compared with 13% of the bipolar II group.
Conclusions: Patients with bipolar I and bipolar II disorder in this study have different neurocognitive profiles. Bipolar I patients have more widespread cognitive dysfunction both in pattern and magnitude, and a higher proportion has clinically significant cognitive impairments compared with patients with bipolar II. This may suggest neurobiological differences between the two bipolar subgroups.