The relationship between signs of cardiovascular deficiency and cognitive performance in old age: a population-based study.

The influence of cardiovascular signs (CVS) on cognitive performance was examined in 227 older adults not suffering from dementia between 75 and 96 years of age who were sampled from the community. Participants received a comprehensive physical examination that included specific evaluation of current CVS, including dyspnea, cardiac murmur, and edema in lower limbs. They were administered tests of digit span, episodic recall and recognition, verbal fluency, and visuospatial skill. CVS were found to predict performance on tests of episodic memory and visuospatial skill, after the effects of age, education, gender, relevant drug use, and mood symptoms were controlled for. Although CVS accounted for relatively little general performance variation, the findings are relevant to the understanding of normal variation in late-life cognitive performance. Finally, CVS increased with age and accounted for a sizable proportion of the age-related cognitive variation.

Depression does not aggravate the episodic memory deficits associated with Alzheimer's disease.

In a population-based study of persons between 75 and 96 years of age, normal old adults (n = 296), patients with Alzheimer's disease (AD; n = 45), and patients with concomitant AD and depression (AD-D; n = 9) were compared on free recall and recognition of slowly and rapidly presented words and digit span. With the exception of forward digit span, the normal old group outperformed the 2 AD groups across all tasks. In free recall, only the normal old group performed better as task pacing decreased; however, all groups benefited from more study time in recognition. This suggests that both AD and AD-D patients have deficits in the ability to use more study time for remembering. Of most importance, the 2 AD groups were indistinguishable for all task variables. This lack of comorbidity effects is discussed relative to the view that depression, much like many other individual-difference variables that affect memory performance in normal aging, may be overshadowed by the influence of the neurodegenerative process in AD.