sundowning

Sundowning, or sundown syndrome, prevalent among people with some form of dementia, is characterized by increased confusion and restlessness beginning in the late afternoon and early evening. The term sundowning was coined by nurse Lois K. Evans in 1987 due to the association between the person's increased confusion and the setting of the sun.

For people with sundown syndrome, a multitude of behavioral problems begin to occur and are associated with long-term adverse outcomes. Sundowning seems to occur more frequently during the middle stages of Alzheimer's disease and mixed dementia and seems to subside with the progression of the person's dementia. People are generally able to understand that this behavioral pattern is abnormal. Research shows that 20–45% of people with Alzheimer's will experience some variation of sundowning confusion. However, despite lack of an official diagnosis of sundown syndrome in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), there is currently a wide range of reported prevalence.