Cognitive impairment in late life schizophrenia and bipolar I disorder
Article first published online: 11 MAR 2012
Copyright © 2012 John Wiley & Sons, Ltd.
International Journal of Geriatric Psychiatry
Volume 28, Issue 1, pages 82–90, January 2013
How to Cite
Meesters, P. D., Schouws, S., Stek, M., de Haan, L., Smit, J., Eikelenboom, P., Beekman, A. and Comijs, H. (2013), Cognitive impairment in late life schizophrenia and bipolar I disorder. Int. J. Geriat. Psychiatry, 28: 82–90. doi: 10.1002/gps.3793
- Issue published online: 6 DEC 2012
- Article first published online: 11 MAR 2012
- Manuscript Accepted: 30 JAN 2012
- Manuscript Received: 18 JUL 2011
- Stichting tot Steun VCVGZ. Grant Number: 184.108.40.206105
- bipolar disorder;
Evidence in younger populations suggests quantitative but not categorical differences in cognitive impairments between schizophrenia and bipolar disorder. It is uncertain whether a similar distinction applies to patients in later life.
We compared the cognitive abilities of older, community-living schizophrenia patients, controlling for their state of symptomatic remission, with those of older euthymic patients with bipolar I disorder. The study included 67 patients with schizophrenia (20 in symptomatic remission, 47 not in symptomatic remission; mean age 68 years) and 74 euthymic bipolar I patients (mean age 70 years), who were compared using analysis of covariance on clinical and neuropsychological variables (e.g., attention/working memory, verbal memory, executive function and verbal fluency) and contrasted with 69 healthy controls.
Remitted (SR) and non-remitted (SN) schizophrenia patients and bipolar I (BP) patients were impaired relative to healthy controls, with mostly large effect sizes for verbal memory (Cohen's d: SR 1.34, SN 1.48, BP 1.09), executive function (Cohen's d: SR 0.87, SN 1.29, BP 0.71) and verbal fluency (Cohen's d: SR 1.09, SN 1.25, BP 0.88), but smaller effect sizes for the domain of attention/working memory (Cohen's d: SR 0.26, SN 0.18, BP 0.52). Differences in cognitive performance between the remitted schizophrenia patients and the bipolar I patients were not significant.
In both older patients with schizophrenia and with bipolar disorder, serious and pervasive cognitive deficits can be demonstrated. Trait-related cognitive deficits in schizophrenia and bipolar disorder may share major phenotypic similarity in later life. Copyright © 2012 John Wiley & Sons, Ltd.