Predictors of cognitive and functional progression in patients with probable Alzheimer's disease.

We followed 65 patients with probable Alzheimer's disease, who were initially mildly to moderately impaired, with semiannual assessments of cognitive and functional performance for up to 4 years. Scores on the Mini Mental State Examination and a combination of instrumental and self-maintenance scale of activities of daily living were regressed on time of examination (measured in 6-month increments) to estimate cognitive and functional progression rates in individual patients. Lower scores on the verbal neuropsychological tests at the time of study entry, more aggressive behavior, and sleep disturbance during the first year of observation predicted faster cognitive progression. Faster functional progression was predicted by paranoid behavior, hallucinations and activity disturbances during the first year and the presence of extrapyramidal signs and lower scores on nonverbal neuropsychological tests at the time of entry into the study. Hallucinations occurred independently of cognitive severity and may identify a distinct subgroup of patients with rapid functional progression. Because of the greater significance of functional progression for caregivers' ability to manage patients, the presence of specific behavior problems early in the disease course may help to identify individuals who will experience greater functional decline and be at risk for earlier institutionalization.