High Intensity Light Therapy in Alzheimer's Disease

The purpose of this study is to determine whether bright light improves the sleep, mood, and behavior of persons with Alzheimer's disease and related dementias (AD) who live in long-term care settings and, if so, to determine the best timing for the light therapy. The light levels being used in the study have been shown to improve depression in persons with seasonal affective disorder (SAD) and to relieve sleep problems in persons with jet lag and other body rhythm disturbances. Because persons with AD often will not remain still in front of a fluorescent panel, this project has involved renovations in the study units that provide for even, regulated, high-intensity light in all public areas of the study settings.