Variation in psychiatric and behavioural symptoms at different stages of dementia: data from physicians' examinations and informants' reports.

An investigation was carried out of psychiatric and behavioural symptoms in non-demented and demented subjects derived from a population study of the very elderly. Information on psychiatric and behavioural symptoms came from two independent sources: a physician's examination and an interview with an informant. The symptoms were grouped into clusters using principal-components analysis. Little agreement was found between the two sources of information on symptoms of anxiety, depression and psychosis. However, there was agreement about an increase in inactivity symptoms as the severity of dementia increased.