Caregivers experience problems negotiating behaviors associated with sundowning; interventions are sought to reduce care-giver burden and keep the adult with Alzheimer's disease from being institutionalized. With the apparent neurobiological evidence surrounding this type of agitation, emphasis is placed on treating sundowning as a failure of the brain to self-regulate the sleep-wake cycle due to advanced age and Alzheimer's disease. Behavioral techniques are encouraged due to the negative side-effects of medications on the aging body. Emphasis on treating sundowning and related agitation by either light therapy or environmental cues or a combination of both is provided. The role of activities in facilitating this treatment is elucidated. © 2003 Taylor & Francis Group, LLC.