I've heard that sundowning may happen with dementia. What is sundowning and how is it treated? Answer From Jonathan Graff-Radford, M.D. The term "sundowning" refers to a state of confusion that occurs in the late afternoon and lasts into the night. Sundowning can cause various behaviors, such as confusion, anxiety, aggression or ignoring directions. Sundowning also can lead to pacing or wandering. Sundowning isn't a disease. It's a group of symptoms that occurs at a specific time of the day. These symptoms may affect people with Alzheimer's disease and other types of dementia. The exact cause of sundowning is not...