A critique of current criteria for early dementia in epidemiological studies

Differences between age‐associated memory impairment and mild dementia have yet to be clarified. Attempts to validate the diagnosis of mild dementia have raised considerable difficulties in the absence of a ‘gold standard’. Agreed criteria of mild dementia are still lacking. Progressive deterioration of cognition is generally held to be a cardinal feature of dementia. Many of the multiple factors which can impair cognition and give a spurious impression of mild dementia still present major methodological problems. Agreed diagnostic criteria, use of standardized measuring instruments, clinical interview, key informant inquiry and possibly psychometric testing are highly desirable in order to detect early dementia. For epidemiological surveys reliable screening instruments are important. It is concluded that, at present, there are too many fundamental conceptual and methodological problems to be overcome before we can successfully undertake large‐scale community epidemiological studies of mild dementia.