[Sundowning of the elderly person].

Sundowning is an aggravation of the elderly's neuropsychiatric symptoms that happen when daylight disappears. Behavioral disorders occur during these hours and are a source of disturbance within the care teams. Caregivers may find themselves unable to do their jobs. The etiology remains unclear despite the pathophysiological hypotheses implying an alteration of the circadian rhythm by the reach of the suprachiasmatic nucleus and the decrease in the production rate of melatonin. There are some therapeutic solutions with pharmacological and non-pharmacological approaches, but the effectiveness has not yet been proved. The main differential diagnosis of this syndrome is the delirium. This article represent this pathology and the existent treatments.