Learning and memory in bipolar and unipolar major depression: Effects of aging

Abstract

Objective: The goal of this study was to examine the effects of aging on neuropsychological functions in bipolar and unipolar major depression. Background: Earlier studies suggested that neurocognitive deficits in mood disorder patients correlate with duration and severity of illness and also that bipolar disorder has a more virulent course than unipolar disorder. We hypothesized that elderly patients with bipolar disorder will demonstrate greater neurocognitive dysfunction than young patients with bipolar disorder and elderly patients with unipolar disorder. Method: A battery of tests of general intelligence and learning and memory was administered to 79 inpatients with major depression referred for electroconvulsive therapy. With patients 60 years of age and older defined as elderly, there were 29 young and 24 elderly unipolar patients and 13 young and 13 elderly bipolar patients. Results: Unipolar and bipolar patients did not differ in measures of general intelligence or global cognitive status. Generally, across tests of memory, young bipolar patients exhibited the best performance and elderly bipolar patients exhibited the poorest performance. Conclusions: The results suggest that over the course of their illness, patients with bipolar disorder experience greater deterioration in memory functions than patients with unipolar disorder. Longitudinal studies are required to support the preliminary findings of this cross-sectional study.