Natural history of behavioural changes and psychiatric symptoms in Alzheimer's disease

Abstract

Background: Alzheimer's disease and other types of dementia are characterised by numerous psychiatric and behavioural changes. Little is known of their natural history.Aims: To investigate the sequence and pattern of these changes throughout the course of dementia.Method: 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.Results: Some changes tend to occur earlier than others but changes can occur at almost any time in the course of dementia.Conclusions: The natural history of behaviour changes in Alzheimer's disease shows great individual variation although some changes tend to follow a recognisable sequence.