Natural history of behavioural changes and psychiatric symptoms in Alzheimer's disease. A longitudinal study.

Abstract

Alzheimer's disease and other types of dementia are characterised by numerous psychiatric and behavioural changes. Little is known of their natural history. To investigate the sequence and pattern of these changes throughout the course of dementia. One hundred people, initially living at home with carers, entered a prospective, longitudinal study. At four-monthly intervals, behavioural and psychiatric symptoms were assessed using the Present Behavioural Examination and Mini-Mental State Examination. Follow-up continued for up to nine years (mean 3.3 years; s.d. 2.4). Patterns of onset and disappearance of these symptoms, their sequence and association with time of death and cognitive decline were analysed. Autopsy confirmed a diagnosis of pure Alzheimer's disease in 48 subjects. Data for this subgroup are presented. Some changes tend to occur earlier than others but changes can occur at almost any time in the course of dementia. The natural history of behaviour changes in Alzheimer's disease shows great individual variation although some changes tend to follow a recognisable sequence.