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Date of Award


Degree Type

Dissertation (On-Campus Access Only)

Degree Name

Doctor of Psychology (PsyD)

Committee Chair

Michael S. Daniel


The objective of this study was to determine the impact of depression on executive functioning and processing speed in older adults after accounting for cerebrovascular risk factors and the effects of different classes of antidepressants. The sample included 822 individuals from the National Alzheimer’s Coordinating Center (mean/SD: age = 74.48/6.48; education = 15.67/3.36). A series of multiple regression analyses were completed. Dependent variables included measures of processing speed (i.e., Digit Symbol, Trail Making Test-A) and executive functioning (i.e., Trail Making Test-B, Digit Span Backward, Animal Fluency, and Vegetable Fluency). Predictor variables were clinical diagnosis of depression and Geriatric Depression Scale-Short Form (GDS) raw scores. Covariates included imaging evidence of cerebrovascular lesions, current diagnoses of diabetes or hypertension, and current antidepressant medication use. After accounting for the covariates, the GDS was a statistically significant predictor of scores on all executive functioning and processing speed measures except Digit Span Backward. Clinical diagnosis of depression was a statistically significant predictor of performance only on Animal Fluency. Together, the depression variables accounted for less than 3% of the variance in scores on the neuropsychological measures.

Available for download on Saturday, October 19, 2019