Behavior Rating Scale for Dementia: development of test scales and presentation of data for 555 individuals with Alzheimer's disease.

We studied 555 Alzheimer's disease patients on the Behavior Rating Scale for Dementia (BRSD), which uses informant interviews to measure behavioral pathology in demented patients. For the 45 items, ratings of present ranged from 5% to 66% of the subjects, with 39 rated present in at least 10%. Twenty-nine items were significantly correlated with dementia severity. The mean number of items present per subject was 13.5; only two subjects had none rated present. Factor analysis identified six factors common to mildly and moderately demented subjects. Six subscales were developed: Depressive Symptoms, Inertia, Vegetative Symptoms, Irritability/Aggression, Behavioral Dysregulation, and Psychotic Symptoms. Interitem consistency was high for three subscales (alpha's from .75 to .80) and moderate for three (alpha's from .48 to .56). Four subscale scores and total scores were significantly but weakly correlated with dementia severity. Detailed results and test instructions are presented in the BRSD manual, available from The Consortium to Establish a Registry for Alzheimer's Disease.