A longitudinal study of the cognitive performance of healthy and demented very old adults
Date
1993
Authors
Hopp, Grace Annette
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Abstract
This study was designed to increase the general understanding of the cognitive abilities of very old adults, and how these abilities related to the use of compensatory memory strategies, awareness of memory functioning, and depressive affect. The initial sample included two groups of adults over the age of 77 years. One group included 95 participants diagnosed as healthy with a Mini-Mental Status Exam (MMSE) M = 28, SD = 2.15. The other group included 11 participants diagnosed as probably Alzheimer's disease (AD) with a MMSE M = 23, SD = 3.82. Participants were tested on five occasions at six-month intervals over a period of two years.
First, psychometric analyses indicated that measures of intelligence, compensation, and depression behave reliably in the two groups of very old adults. Second, these measures differentiate between those in the early stages of AD and health elderly individuals, with the latter showing higher levels of performance than the former across the five occasions.
Third, overall, participants with AD used fewer compensatory memory strategies, (such as memory aids) than did healthy adults. In addition, healthy adults used more external strategies (such as notes), while participants with AD reported that they relied increasingly more on others.
Fourth, there was a moderate relationship between intelligence and awareness of deficits. Participants with AD, who experienced greater levels of cognitive deficits, were less aware of their dysfunction than were nonimpaired, healthy participants.
Fifth, healthy participants and those with AD had similar levels of depression in the six months following diagnosis, but the depression level of healthy participants increased over the two years. As well, depression was related to observed indicators of awareness, and combined with diagnosis had a significant impact on the Performance subscale of the Wechsler Adult Intelligence Scale-Revised.