Neuropsychiatric disturbance in Alzheimer's disease clusters into three groups: the Cache County study

Objective We investigated the frequency and inter-relation ship of neuropsy chiatric disturbances in a population sample of persons suffering from Alzh eimer's disease (AD). Method Screening 5,092 elderly residents (90% of the population aged 65 and older) of Cache County, Utah, for dementia, we identified 198 pet-sons wit h AD using a comprehensive neuropsychiatric examination protocol. This exam ination included the Neuropsychiatric Inventory (NPI), a widely used measur e of dementia-associated neuropsychiatric disturbances. Results Overall, 60% of individuals with AD reported one or more neuropsych iatric symptoms, A latent class analysis revealed that these participants c ould be classified into three groups (classes) based on their neuropsychiat ric symptom profile. The largest class included cases with no neuropsychiat ric symptoms (40%) or with a mono-symptomatic disturbance (19%). A second c lass (28%) exhibited a predominantly affective syndrome, while a third clas s (13%) had a psychotic syndrome. Conclusion Data from this first US population-based study of AD-associated neuropsychiatric disturbances suggest that a significant majority of person s with AD suffer from one or more neuropsychiatric disturbance. Based on ph enomenological study, the spectrum of neuropsychiatric symptoms in AD can b e empirically classified into three groups: an affective syndrome, a psycho tic syndrome and other neuropsychiatric disturbance. The biologic and predi ctive validity of this classification merits further investigation. Copyrig ht (C) 2001 John Wiley & Sons, Ltd.