Bipolar Disorders in Late Life: Early Days, Gradual Progress

Abstract

Three articles in this issue of the American Journal of Geriatric Psychiatry journal focus on late-life bipolar disorders (BDs) and aim to characterize their neurobiologic underpinnings. These studies assessed euthymic older patients with BD and aimed to identify traits that may help to elucidate underlying pathophysiologies and etiologies. Existing literature regarding late-life mania and BDs has emphasized a number of robust findings including the high prevalence of cognitive dysfunction (Young et al. 1 ), frequent abnormalities on structural neuroimaging, and the association between these disorders and neurologic disorders,especially cerebrovascular disease (Shulman and Herrmann 2 ). The studies reported in this issue describe findings from the application of cognitive assessments, neuroimaging methods, and medical evaluations. Studying such dimensions in older patients with BD can ultimately have direct clinical and public health importance in these aged patients, who carry significant morbidity, mortality, and economic burden (Sajatovic and Blow 3 ). They also can have heuristic value through shedding light on the nature of BDs in younger patients, a much larger clinical cohort. CONTRIBUTIONS IN THIS ISSUE Tsai et al. 4 investigated differences in cognitive function, medical burden, and sociodemographic characteristics between elderly community-dwelling Taiwanese euthymic patients with BD and age and education matched normal individuals in a case– control study. All subjects had measurements of global cognitive function using the Clock-drawing test and Mini-Mental State Examination and an assessment of medical morbidity and health. Elderly patients with BD were more likely than the comparison group to have diabetes mellitus, smoking habit, and unfavorable social functioning. Mini Mental State scores were significantly lower in the patients than in the comparison group. Two surprising findings emerged from this study. One was the association of BD with atopic diseases, implicating a possible immunologic contribution. The second was the lack of “circulatory morbidity” in the patient group; although they had increased vascular risk factors including diabetes and smoking, they had lower blood pressure values and diagnosed hypertension relative to the comparison group. Therefore, these findings conflict somewhat with a strong association of stroke and cerebrovascular disease with late-life BD, including a previous report using a large Taiwanese health database; 5 the authors suggest some explanations, but their current findings await further investigation.