Executive dysfunction in elderly bipolar manic patients.

Objective: This study used neuropsychological measures of executive skills to examine the functioning of frontostriatal networks in elderly bipolar patients.

Design: The authors hypothesized that elders with bipolar mania would exhibit poor executive functions relative to both elderly comparison subjects and depressed patients.

Setting: The study was conducted in the geriatric psychiatry services of a university hospital.

Participants: Nondemented elders: 14 with bipolar disorder I, manic (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), 14 with unipolar major depression (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), and 14 nonpsychiatric comparison (NC) subjects.

Measurements: Executive functions were assessed with the initiation/perseveration subscale of the Dementia Rating Scale and the manual Go/No-Go tasks from the extended initiation/perseveration scale.

Results: Manic elders demonstrated poor performance on tasks of initiation/perseveration and response inhibition, and performed significantly worse than both depressed patients and NC subjects. In this sample, there was no evidence for a relationship between severity of manic symptoms and executive performance.

Conclusion: These findings extend the observation that elderly bipolar manic patients have deficits in executive functioning compared with NC samples and provide evidence that the executive deficits demonstrated by bipolar manic elders can be more severe than those in unipolar depressed elders. As executive functions require frontostriatal integrity, these observations support investigation of specific frontostriatal network abnormalities in late-life bipolar disorder.