During what time of day do symptoms of Alzheimer disease tend to increase, a phenomenon known as sundowning?

Sundowning refers to the phenomenon where symptoms of Alzheimer’s disease and other forms of dementia worsen during the late afternoon or evening. This increase in agitation, confusion, and disorientation typically occurs as the day comes to a close, leading into the nighttime hours.

The reasons behind sundowning can be multifaceted. These may include a person's internal body clock becoming disrupted, fatigue from the day’s activities, and environmental factors such as fading light and increased shadows, which can create anxiety or disorientation in individuals with cognitive impairments.

The other times of day, such as morning and noon, are generally when individuals may feel fresher and more cognitively alert, reducing the likelihood of exacerbated symptoms. Therefore, evening and nighttime are specifically associated with this increase in symptoms for those with Alzheimer’s disease, making it the correct answer.