Sundown syndrome in severely demented patients with probable Alzheimer's disease.

A retrospective review of 71 patients with probable Alzheimer's disease was analyzed with respect to nursing evaluations of sundowning status (recurring confusion or agitation in the late afternoon or early evening). The prevalence of sundowning (including probable sundowners) was 24%. Sundowners and non-sundowners differed with regard to number of sedatives received daily, particularly chloral hydrate, and the number of days on the inpatient unit. There were no differences between sundowners and non-sundowners with respect to other types of medications, medical diagnoses, current age, age of onset of Alzheimer's disease, or Mini-Mental State Exam. Restlessness was the most common sundowning behavior, although multiple behavioral disturbances were seen. This survey suggests that the sundown syndrome is a common problem in severely demented Alzheimer's patients and requires further study.