Effects of Dynamic Lighting on Improving Sleep and Mood in Older Adults With Dementia.

Light is the most important environmental element that is not only necessary to fulfill visual tasks but also is the main stimulus that regulates circadian rhythms. Daily exposure to proper lighting at the right time is reported as an effective non-pharmacological treatment to improve sleep disorders in various age groups including older adults. Several clinical studies have demonstrated the benefits of bright light therapy to improve sleep duration and sleep efficiency at night and reduce daytime sleepiness and behavioral disturbance (i.e., agitation, depression) in older adults. In most of these studies, lighting intervention includes a lightbox that exposes participants to an extra lighting source with specific characteristics (i.e., blue-enriched bright light) for only a few hours without considering the impacts of other lighting sources that individuals are exposed to throughout the day. A significant impediment to administrating bright light therapy for older adults with dementia is that these individuals typically require reminders to remain seated and awake in front of a lightbox long enough to benefit from the bright light exposure. An alternative way to deliver bright light is through providing circadian-effective ambient lighting. The circadian system responds best to high-intensity short-wavelength light (peak wavelength of 480 nm). However, the lighting design in long-term care facilities does not necessarily provide adequate intensity and spectrum to stimulate circadian rhythms in elder residences. Studies reported poor lighting conditions in nursing homes. According to these studies, daytime lighting in these institutions is not even sufficient to fulfill older adults' visual needs, while light at night is relatively often excessive. Thus, this study will be carried out to achieve the following aims:

Aim1: Investigate the effect of a dynamic lighting condition on circadian activity rhythms and selected sleep parameters in older adults with dementia.

Aim2: Evaluate the effect of a dynamic lighting condition on mood.

Findings from this study will provide initial guidance to the designers and administration of memory care facilities as to the lighting design recommendations of greatest benefits to the sleep, mood, and well-being of institutionalized older adults diagnosed with dementia.

The participants will be recruited from two memory care facilities from the greater Phoenix area, based on the recommendation of the managers at the memory care facilities.