Tailored lighting intervention improves measures of sleep, depression, and agitation in persons with Alzheimer's disease and related dementia living in long-term care facilities

• Published in: Clinical interventions in aging Vol. 9; pp. 1527 - 1537
• Main Authors: Figueiro, Mariana G, Plitnick, Barbara A, Lok, Anna, Jones, Geoffrey E, Higgins, Patricia, Hornick, Thomas R, Rea, Mark S
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01.01.2014; Taylor & Francis Ltd; Dove Press; Dove Medical Press
• Subjects: Activities of Daily Living; ADRD; Aged, 80 and over; agitation; Alzheimer Disease - complications; Alzheimer's disease; Behavior; Care and treatment; Circadian rhythm; Circadian Rhythm - radiation effects; circadian rhythms; Cornea; Dementia; Dementia - complications; Depression - prevention & control; Female; Health aspects; high correlated color temperature; Humans; Light therapy; Lighting; Male; Melatonin; Mental depression; Mental disorders; Mental Status Schedule; Nursing Homes; Older people; Original Research; Phototherapy; Psychomotor Agitation - prevention & control; Sleep disorders; Sleep Wake Disorders - prevention & control; Surveys and Questionnaires; Treatment Outcome; United States; Cleveland Ohio; United States > US; sleep disorders; ADRD; light therapy; circadian rhythms
• ISSN: 1178-1998; 1176-9092; 1178-1998
• DOI: 10.2147/CIA.S68557

Light therapy has shown great promise as a nonpharmacological method to improve symptoms associated with Alzheimer's disease and related dementias (ADRD), with preliminary studies demonstrating that appropriately timed light exposure can improve nighttime sleep efficiency, reduce nocturnal wandering, and alleviate evening agitation. Since the human circadian system is maximally sensitive to short-wavelength (blue) light, lower, more targeted lighting interventions for therapeutic purposes, can be used. The present study investigated the effectiveness of a tailored lighting intervention for individuals with ADRD living in nursing homes. Low-level "bluish-white" lighting designed to deliver high circadian stimulation during the daytime was installed in 14 nursing home resident rooms for a period of 4 weeks. Light-dark and rest-activity patterns were collected using a Daysimeter. Sleep time and sleep efficiency measures were obtained using the rest-activity data. Measures of sleep quality, depression, and agitation were collected using standardized questionnaires, at baseline, at the end of the 4-week lighting intervention, and 4 weeks after the lighting intervention was removed. The lighting intervention significantly (P<0.05) decreased global sleep scores from the Pittsburgh Sleep Quality Index, and increased total sleep time and sleep efficiency. The lighting intervention also increased phasor magnitude, a measure of the 24-hour resonance between light-dark and rest-activity patterns, suggesting an increase in circadian entrainment. The lighting intervention significantly (P<0.05) reduced depression scores from the Cornell Scale for Depression in Dementia and agitation scores from the Cohen-Mansfield Agitation Inventory. A lighting intervention, tailored to increase daytime circadian stimulation, can be used to increase sleep quality and improve behavior in patients with ADRD. The present field study, while promising for application, should be replicated using a larger sample size and perhaps using longer treatment duration.