n. A form of agitation or anxiety exhibited at night by some elderly hospital patients and nursing home residents.

Example Citations:
Even in the I.C.U., the psychosis often resolves spontaneously, with the coming of morning or sleep. Sometimes it lingers through the day. Severe agitation usually occurs only at night, however, which is why doctors and nurses often call it sundowning, also a kind of delirium common in nursing homes.
—Sandeep Jauhar, “When a Stay in Intensive Care Unhinges the Mind,” The New York Times, December 8, 1998

“Some forms of dementia are reversible,” Eleanor Goldberg, executive director of the Alzheimer’s Association in Portland, says. “And, Alzheimer patients will have good days and bad days. Even a particular time of the day can be more difficult. The late afternoon is a tough time. It’s called ‘sundowning.’ People become more anxious and their behavior escalates.” Goldberg says.
—Candace Dean, “Memory loss has many causes,” Portland Press Herald (Maine), January 31, 1999

Earliest Citation:
Conditions that can be confused with epilepsy include:...

Acute confusion or “sundowning”.
—James W. Cooper, “Monitoring anticonvulsant drug interactions and blood levels,” Nursing Homes Long Term Care Management, September 1, 1986

Related Words: