Stability and course of neuropsychological deficits in manic and depressed bipolar patients compared to patients with Major Depression

BACKGROUND: Neuropsychological functioning varies across different subgroups of patients with affective disorders; yet there have only been a few studies pointing out distinctive neuropsychological profiles and following-up possible changes in this functioning. The aim of this study was to compare neuropsychological functioning across remitted manic or depressed patients with bipolar disorder compared to remitted patients with Major Depression and to explore the course of their cognitive functioning. METHODS: 30 patients with Major Depression, 17 manic bipolar patients, and 22 depressed bipolar patients were assessed for memory, attention, and executive functions using the Auditory Verbal Learning Test (AVLT), the Modified Card Sorting Test (MCST), the Attention Network Test (ANT), and Stop-Signal Task. Neuropsychological assessment was performed at discharge and seven weeks after discharge. RESULTS: The three groups showed different neuropsychological performance at discharge. Regarding selective attention and speed of responding the manic bipolar patients displayed poorer performance than the other two groups. Furthermore, follow-up assessment revealed that although all patient groups demonstrated an overall improvement, some deficits (especially in executive functions) remain. Manic bipolar patients showed again the worst performance. Depressed bipolar patients, however, were not observed to show a poorer outcome than depressed unipolar patients. CONCLUSIONS: This study provides further evidence for distinct neuropsychological functioning in patients with affective disorders depending on their state of illness. Furthermore, it supports the hypothesis that especially manic bipolar patients stay impaired in certain cognitive functions after remission. These findings may be of clinical relevance regarding treatment and prevention programs and emphasize the need of further research investigating stability and course of patients with mood disorders.