Do memory complaints indicate cognitive impairment? - A review

According to the growing clinical interest in early indicators of dementia, numerous studies have examined the association between subjective memory c omplaints and cognitive performance in old age. Their results are contradic tory. In this paper, studies carried out over the last 10 years are compare d with regard to the study design and the assessment instruments used. The results are discussed with particular reference to the diagnostic validity of subjective memory complaints. The majority of case-control studies and c ross-sectional studies of non-representative samples could not demonstrate an association between subjective memory complaints and cognitive performan ce. Most field studies of larger representative population samples, however , have come to the opposite conclusion. A consistent assessment of these st atistically significant associations against the background of diagnostic v alidity showed that memory complaints cannot be taken as a clear clinical i ndicator for cognitive impairment. Subjective memory complaints may reflect depressive disorders and a multitude of other processes, of which an objec tive impairment of cognitive performance is just one aspect. As a consequen ce, an inclusion of subjective memory complaints as a diagnostic criterion for the diagnosis of "mild cognitive disorder" according to ICD-10 is not j ustified.