The Association between Verbal Fluency Deficits, Depression, And Quality of Sleep among Alzheimer ’s disease Patients

Alzheimer’s disease represents a growing health challenge in the elderly population across the globe. The disease is associated with negative implications on survival, cost-of-care, and quality-of-life (World Alzheimer Report, 2015). Of the various debilitating cognitive symptoms associated with Alzheimer’s disease, language deficits are associated with much greater clinical relevance because of its interference with aspects such as self-care, recreational activities, employment, and behavior. One of the early signs of aphasia in Alzheimer’s disease is impairment in verbal fluency (Ferris & Farlow, 2013). Because of the widespread trend of bilingualism in today’s scenario (Ansaldo & Saidi, 2014), it is essential to study language deficits within the framework of the bilingual brain. Therefore, in this study, second language deficits as measured by verbal fluency tasks were assessed in Alzheimer’s disease patients as compared to healthy elderly individuals. Additionally, the study evaluated the relationship between second language deficits and depression and sleep disturbances in Alzheimer’s disease patients relative to healthy older individuals. No correlation was found between depression and sleep and verbal fluency tasks in Alzheimer’s patients. However, the rate of depression was significantly higher in Alzheimer’s patients. In healthy individuals, there was a significant effect for habitual sleep efficiency on semantic task scores, F(1, 6) = 6.069, p = .049. Furthermore, semantic task score was significantly higher than phonemic task score in healthy individuals, t(9) = 3.939, p = .003, suggesting an increased cognitive load associated with the phonemic task.