Subclinical cognitive impairment: epidemiology and clinical characteristics.
Subclinical cognitive impairment is commonly reported in elderly populations, but its clinical significance is largely undetermined. It is commonly perceived as a normal feature of the aging process or a separate nosological entity. The clinical status of this disorder is explored herein by reference to longitudinal observations. It is concluded that persons with subclinical cognitive impairment constitute a highly heterogeneous group. There is an elevated risk in this group for senile dementia, with an estimated 18% incidence rate over 3 years, but in the majority of cases, this problem is more commonly associated with depressive symptomatology and physical illness. Only 13% of persons with recent observable change in cognitive functioning appear to have a totally benign and transient syndrome. Caution should be exercised in applying single unifying nosological entities such as age-associated memory impairment to this group of the elderly.
Ritchie
K
K
Institut National de la Santé et de la Recherche Médicale (INSERM) E99-30, Montpellier, France.
Ledésert
B
B
Touchon
J
J
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D003072:Cognition Disorders / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D003866:Depressive Disorder / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D005602:France; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics; D012016:Reference Values; D015203:Reproducibility of Results