Prevalence of mild cognitive impairment in an elderly community sample

The term "mild cognitive impairment" refers to cognitive deficits which exc eed normal physiological aging processes, but do not fulfill the criteria f or dementia. While recent studies indicate that the respective deficits can be reliably assessed, different diagnostic criteria have prevented a wide application of this diagnosis in clinical practice. The aims of the present study were (1) to assess the prevalence rates of four current diagnostic c oncepts and (2) to investigate mild cognitive impairment with respect to ps ychological and sociodemographic variables. Data from 202 probands recruite d from the interdisciplinary longitudinal study on adult development were a nalyzed. On the time of examination, probands were between 60 to 64 years o ld and in a good health. The following prevalence rates were determined: 13 .5% for age-associated memory impairment (AAMI), 6.5% for age-consistent me mory impairment (ACMI), 1.5% for late-life forgetfulness (LLF), and 23.5% f or aging-associated cognitive decline (AACD). Complaints of cognitive defic its were significantly correlated with higher scares on depression and neur oticism scales but with none of the neuropsychological measures. Reduced pe rformance in neuropsychological tests was associated with a lower education al level and socioeconomic status. We conclude that the prevalence rates of mild cognitive impairment are highly dependant on the diagnostic criteria applied. In this respect the self-report of cognitive decline might be a le ss useful criteria. Longitudinal studies are warranted to further eludicate the predictive value of these diagnostic criteria.