The course of neuropsychiatric symptoms in dementia. Part II: relationships among behavioural sub-syndromes and the influence of clinical variables

Background Although several studies have mentioned associations between neuropsychiatric symptoms, there have been no prospective studies determining interrelations among behavioural sub‐syndromes. Objectives To investigate the influence of several clinical variables on the course of neuropsychiatric symptoms, and to determine interrelationships between the behavioural sub‐syndromes. Methods One hundred and ninety‐nine patients with dementia were assessed every six months for two‐years, using the Neuropsychiatric Inventory (NPI) to evaluate neuropsychiatric symptoms. Results Age, sex, and socioeconomic status were not associated with a specific neuropsychiatric symptom. Greater cognitive impairment was related to more severe psychosis, and dementia stage influenced the course of total NPI problems. There were strong interrelations among most behavioural sub‐syndromes. The sub‐syndrome hyperactivity was of influence on the development of psychosis, but not vice versa. Neither was the sub‐syndrome mood/apathy of influence on the course of psychosis. Conclusions While different neuropsychiatric symptoms have their own specific correlates, there is a strong interrelationship between behavioural sub‐syndromes. The data have implications for clinicians and the nosology of neuropsychiatric symptoms in dementia. Copyright © 2005 John Wiley & Sons, Ltd.