When evening approaches, caregivers of dementia patients know to be on their guard for sundowning: a constellation of behaviors that can include restlessness, agitation, aggression, confusion, and wandering.
“Nurses will talk about it like almost a light switch,” says Trey Todd, a neuroscientist at the University of Wyoming who wrote a 2020 review of the scientific literature on sundowning. These behaviors tend to begin around the same time in the late afternoon or early evening and last for roughly four hours.
Sundowning is frequently described among patients with Alzheimer’s disease and related dementias, but not all people with those disorders experience it. Reports of its prevalence differ, but Todd says the most conservative estimates suggest about 20 percent
