The Relationship Between Cognitive Abilities and Functional Decline in Older Adults Diagnosed with Alzheimer's Disease

• Main Author: West, Sarah
• Format: Others
• Published: NSUWorks 2012
• Subjects: Activities of Daily Living; Alzheimer's Disease; Cognition; Functional Decline; Neuropsychology; Psychology
• Online Access: http://nsuworks.nova.edu/cps_stuetd/75; http://nsuworks.nova.edu/cgi/viewcontent.cgi?article=1074&context=cps_stuetd

This study examined the relationship between five neurocognitive domains, including memory, visual-spatial skills, executive functioning, language, and attention, and three instrumental activities of daily living (IADLs), (financial management, medication management, and driving), as well as three basic activities of daily living (ADLs), including dressing, feeding, and grooming. Subjects were community dwelling older adults diagnosed with Alzheimer's Disease (AD) ranging in severity from mild to severe. Correlation and regression models were used to analyze the relationship between neurocognitive domains and self-care activities. All of the neurocognitive domains were significantly but mildly correlated with declines in IADLs, and all of the neurocognitive domains, except memory, were significantly but mildly correlated with ADL decline. None of the regression models, except driving, produced significant results. The hypotheses were based on the belief that overlap occurs between declines in cognitive domains and self-care skills. The results of this study support the assertion that global cognitive decline occurs followed by declines in IADLs and later declines in ADLs. Thus, instead of specific neurocognitive domains predicting decline in individual self-care skills, this research indicates that the degree of severity of cognitive decline is predictive of impairments in IADLs or ADLs with milder global impairment predicting IADLs and more pronounced decline predicting declines in ADLs. Degree of severity may have been more predictive because while individuals vary in cognitive symptom presentation, the course of AD always progresses from mild to more severe. The role of over-learning also potentially impacted the results of the study. Individuals learn and daily practice ADLs at a young age causing them to require less higher level cognitive skills (over-learned). Since over-learned IADLs require less higher level cognition, they were preserved longer in AD course, thus declining after global cognitive impairment. Clinicians need to thoroughly assess the degree to which an individual has over-learned a task in order to make the most accurate recommendations. If an individual has milder global decline, IADLs are likely to be impaired, and if an individual has moderate global decline with memory reaching a floor, ADLs are likely to be impaired.