Date of Award

Summer 8-7-2019

Level of Access

Open-Access Thesis

Degree Name

Master of Arts (MA)

Department

Psychology

Advisor

Marie Hayes

Second Committee Member

Ali Abedi

Third Committee Member

Fayeza Ahmed

Additional Committee Members

Clifford Singer

Abstract

The continuing growth in the demographic of aging individuals in the United States creates concern for diseases of aging that are chronic, notably unipolar depressive disorders. The high rates of depression in the aging population are a concern because of the strong association between late-life depression and cognitive impairment. Poor cognitive functioning is a hallmark of aging related neurological disorders, the most prevalent being Alzheimer’s Disease (AD). Sleep disorder is a core symptom of depression, and is definitively associated with the development of mild cognitive impairment (MCI), the prodrome of AD. MCI is also characterized by similar types of sleep disturbance including sleep fragmentation, which consists of excessive awakenings during the night that leads to atypical suppression of night-time full awakenings and chronic sleep debt that impairs daytime attention and cognition as a consequence of poor sleep quality. The main hypothesis of this study is that current or historical depression in older adults will be associated with poor sleep quality and cognitive impairment. Participants (N=50) from 65-85 years were assessed to determine the impact of depression status on sleep disturbance and cognitive variables. Individuals endorsing current depression (n=9), history of diagnosed depression but no current depression (n=7), or no current depression (n=34) were tested for 7 nights using wrist actigraphy and self-report sleep diaries to assess various sleep parameters used to identify sleep disturbance. Memory consolidation was probed surrounding one night of sleep using a simple procedural memory task and one-month follow-up assessment was used to assess a variety of neurocognitive domains including immediate and delayed recall, visuospatial abilities, etc. Results from this study revealed that individuals with current depression showed poorer sleep quality (i.e. shorter sleep time, lower mean sleep efficiency, longer sleep latency, etc.) and self-reported more sleep disturbances and greater daytime dysfunction when compared with individuals with no current depression or depressive history (p’s < .05). Results of impairment on cognitive tasks from participants with current depression or a history of diagnosed depression were not found. These results provide evidence of an association between sleep disturbance and late-life depression. Cognitive performance of depressed older adults warrant further exploration.

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