Sloane PD, Zimmerman S, Williams C, Preisser J, Barrick AL, Hickman S.

High intensity, low glare environmental light (HILGEL) as therapy in Alzheimer's disease: results of a randomized trial.

University of North Carolina at Chapel Hill, Cecil G. Sheps Center for Health Services Research, 725 Aiport Rd, University of North Carolina, Chapel Hill, NC 27599-7590. psloane@med.unc.edu

Bright light therapy improves sleep and depression in normal individuals and, therefore, could be an alternative to medication for long-term care residents with dementia. The standard method of light therapy to cognitively intact persons—sitting in front of light box—is impractical in dementia. To test whether HILGEL could provide a more feasible treatment method, a facility unit-level intervention trial, with crossover, studied 66 residents with dementia in two settings: a psychiatric hospital and a dementia-specific assisted living facility. Four intervention patterns were studied: morning HILGEL, late afternoon / early evening HILGEL, full-day HILGEL, and industry standard lighting (control). Interventions were presented in 3-week blocks; outcomes were measured during the second half of each block. Primary outcomes included sleep duration and quality (measured by wrist actigraphy), daytime activity (evaluated by conducting 48 hourly observations during each study block), depressive symptoms (measured using the Cornell Scale for Depression in Dementia), and agitation (measured by direct observation and staff report [using the Cohen-Mansfield Agitation Inventory]. A total of 343 blocks of data were collected, with subjects remaining in the study variable numbers of blocks. Preliminary results (to be updated prior to the conference) indicate a strong, significant increase in total sleep time, nonsignificant trends toward reducing sleep bouts and depressive symptoms, and a nonsignificant trend toward increasing agitated behaviors. Rates of side effects did not differ between treatment conditions and the control condition; however, a borderline significant trend toward increased adverse effects (hospitalizations) among the control group was noted. This study, the largest conducted to date on environmental light as therapy for Alzheimer's disease, raises intriguing therapeutic implications for long-term care.

 

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