Cognitive status and development in the oldest old: a longitudinal analysis from the Heidelberg Centenarian Study.

In the present study, we investigated cognitive status, cognitive development and the effect of mortality on cognitive changes in very old age. Analyzing data from the population-based Heidelberg Centenarian Study, results revealed that centenarians differed quite strongly in their cognitive capacities. While about half of the population showed moderate to severe cognitive impairment, one quarter was found to be cognitively intact. Moreover, analyzing cognitive change over a period of 1.5 years, centenarians' cognitive performance was revealed to be rather stable. Finally, only a small effect of mortality on cognitive status and changes was detected, supporting a recent hypothesis that the terminal decline or drop in cognitive functioning decreases in very old age.