Sleep disturbance in mild to moderate Alzheimer's disease

Background and purpose: To determine the prevalence of sleep disturbance in a memory clinic population of Alzheimer's disease (AD) patients and identify its clinical correlates. Patients and methods: Data from 215 attendees at a memory clinic, who were diagnosed with Alzheimer's disease, were examined. This included data from cognitive, functional and neuropsychological assessments. Sleep disturbance was determined using the question about diurnal rhythm disturbance on the BEHAVE-AD questionnaire. Two groups, with and without sleep disturbance, were compared. Group differences were analysed using univariate analysis and stepwise logistic regression analysis. Results: The prevalence of sleep disturbance in this sample was 24.5%. The BEHAVE-AD 'aggressiveness' (P=0.009) and 'global rating' (P=0.029) (a measure of global impact of behavioural disturbance) were found to be significant predictors of sleep disturbance in AD. Conclusions: Sleep disturbance in AD is associated with other behavioural symptoms, notably aggressiveness. Sleep disturbance in AD has significant impact on the patient and/or caregiver. Consideration of co-morbid behavioural symptoms may aid the clinician in choosing a suitable treatment for sleep disturbance in AD.