Light therapy for insomnia in older adults.

Exposure to bright light suppresses the production of melatonin and contributes to the regulation of the circadian rhythm. Because of environmental and medical conditions, older adults are less likely than younger adults to receive the prolonged, high intensity, daily bright light needed to promote a satisfactory sleep-wake cycle. The best available evidence for bright light therapy is in the management of seasonal affective disorder, which is relatively infrequent in the elderly population. For older adults with chronic insomnia, dementia, and nonseasonal depression, there is no consensus on the optimum treatment protocol for bright light therapy. However, in addition to sleep improvement, bright light therapy may be used to reduce unwanted behavioral and cognitive symptoms associated with dementia and depression in the elderly.