A LONGITUDINAL-STUDY OF BEHAVIORAL PATHOLOGY ACROSS 5 LEVELS OF DEMENTIA SEVERITY IN ALZHEIMERS-DISEASE - THE CERAD BEHAVIOR RATING-SCALE FOR DEMENTIA

As part of the Alzheimer's Disease Cooperative Study (ADCS) Instrument Development Project, the CERAD Behavior Rating Scale for Dementia (BR SD) was examined for its sensitivity to degree of cognitive impairment , its test-retest reliability, and its sensitivity to longitudinal cha nge. Sixty-four normal elderly participants and 261 patients with AD s tratified into severity groups based on Mini-Mental State Exam (MMSE) scores were rated on the BRSD at baseline and 12-month followup visits . A subset of subjects was evaluated at a 1-month follow-up visit. Bas eline BRSD Total Score discriminated the normal group from each AD gro up, and mean Total Score significantly increased with increasing demen tia severity. Test-retest reliability between baseline and 1-month Tot al Scores was satisfactory for all AD groups. Longitudinal change was evaluated by 12-month change scores, which were significant in only th e normal and in one AD group. From the results, we argue that the valu e of behavioral pathology assessment in clinical trials would be enhan ced if additive scores were based on groups of correlated items rather than on a broad array of behaviors, some of which may increase and ot hers may decrease in frequency as AD progresses.