Objective: To assess the validity of the Neurobehavioral Rating Scale (NRS) in patients with Alzheimer's disease (AD) or multi-infarct dementia (MID) and to characterize the cognitive, psychiatric, and behavioral disturbances that occur in these patients.
Design: Cross-sectional evaluation.
Setting: West Los Angeles VAMC Geropsychiatry Inpatient Unit, Neurobehavior Inpatient Unit, and Dementia Clinic; UCLA Alzheimer's Disease Clinic.
Patients: Convenience sample of 61 patients with AD and 22 patients with MID.
Main outcome measure: The NRS, a 27-item observer-rated instrument that measures cognitive, psychiatric, and behavioral disturbances.
Results: The NRS demonstrated content and convergent validity in this patient group. Principal components analysis of the NRS ratings identified a six-factor solution, and each factor contained clinically related symptoms. The factors were Cognition/Insight, Agitation/Disinhibition, Behavioral Retardation, Anxiety/Depression, Verbal Output Disturbance, and Psychosis. Among the patients with AD, agitation, disinhibition, hostility, poor insight, poor motivation, suspiciousness, and delusions were more severe in patients with more advanced dementia. Depressive symptoms occurred with equal severity in patients with mild and advanced dementia, but depressed mood was more severe in patients with earlier age of onset of AD.
Conclusion: The NRS is a useful instrument for structured assessment of a broad range of cognitive, psychiatric, and behavioral disturbances in patients with dementia.