Are memory complaints predictive for dementia? A review of clinical and population-based studies

Objectives. To review studies that have reported on the prevalence of memor y complaints and the relationship between memory complaints and impairment or decline (dementia) in elderly individuals Data sources and study selection. All publications in the English language relating to memory complaints, memory impairment, cognitive disorder and de mentia in MEDLINE, PSYCHLIT and EMBASE computerized databases, together wit h a search of relevant citations. Data synthesis. The prevalence of memory complaints, defined as everyday me mory problems, shows a large variation of approximately 25-50%. A high age, female gender and a low level of education are generally associated with a high prevalence of memory complaints. In community-based samples of elderl y subjects an association has been found between memory complaints and memo ry impairment, after adjustment for depressive symptomatology. Memory compl aints predict dementia after a follow-up of at least 2 years, in particular in those with mild cognitive impairment, defined as Mini Mental State Exam ination (MMSE) > 23. Memory complaints in highly educated elderly subjects may be predictive of dementia even when there is no indication of cognitive impairment on short cognitive screen tests. The shift in methodology which is noticeable in the recently published major studies is discussed as a po ssible explanation for the established association between memory complaint s and decline in memory (or dementia) in elderly subjects. Three methodolog ical factors, in particular, are responsible for the results: community-bas ed sampling, longitudinal design and the treatment of variables such as dep ression, cognitive impairment and level of education. Conclusion. Memory complaints in elderly people should no longer be conside red merely as an innocent age-related phenomenon or a symptom of depression . Instead, these complaints deserve to be taken seriously, at least as a po ssible early sign of dementia. Copyright (C) 2000 John Wiley & Sons, Ltd.