Personality change precedes clinical diagnosis of dementia of the Alzheimer type.

We examined personality changes reported by a collateral source on the Blessed Dementia Scale in people who were nondemented when they entered a longitudinal study. Of the 108 participants examined here, 68 received a clinical diagnosis of dementia at some point after entry into the study. The other 40 participants died and came to autopsy with a clinical diagnosis of no dementia; however, 14 received a neuropathological diagnosis of Alzheimer's disease. The results indicate that initial personality changes often occur early, even earlier than clinical diagnosis. Individuals without a clinical diagnosis who showed presence of the disease at autopsy experienced personality changes comparable with those of individuals who had received a clinical diagnosis. Personality changes may aid in the early detection of dementia of the Alzheimer type, which could facilitate early treatment.