The impact of cognitive functioning on mental health in community-dwelling older adults
The purpose of this study was to examine the gray area between intact cognitive functioning and mild cognitive impairment among sexagenarians, octogenarians, and centenarians. Gender, race, and age group differences, as well as changes over time in cognitive functioning were assessed. The impact of cognitive functioning and instrumental activities of daily living on depression, positive affect, and negative affect was also examined. Data were analyzed from the Georgia Centenarian Study, which comprised of three hundred twenty-one participants at Time 1 (Tl) and two hundred one participants at Time 2 (T2). All participants were cognitively intact and community dwelling at Tl. Results concerning gender differences indicated women had higher cognitive functioning at Tl, but there was no gender difference at T2. Race and age group differences were found at Tl and T2 with Blacks and centenarians having significantly lower cognitive functioning compared to Whites, sexagenarians, and octogenarians. Race differences persisted after controlling for education and self-reported health. The longitudinal analysis indicated mean cognitive functioning scores were significantly lower at T2. Centenarians experienced a steeper decline in cognitive functioning over a shorter period of time compared to the combined group of sexagenarians and octogenarians. The results of the cross-sectional predictors of mental health indicated self-reported health was a significant predictor of depression, positive affect, and negative affect. Cognitive functioning was not a significant predictor of the three areas of mental health, and instrumental activities of daily living were only a significant predictor of depression. In the longitudinal analysis, cognitive functioning at Tl and functional health at Tl did not predict depression at T2.