Effects of bright light exposure on the behavioral and psychological symptoms of dementia and the burden on caregivers in institutionalized elderly with cognitive decline.

Abstract

The purpose of this study was to examine the effects of bright light exposure on behavioral and psychological symptoms of dementia (BPSD), including sleep disturbances and the burden on caregivers in institutionalized elderly with cognitive decline. The subjects included eight people with cognitive decline (mean [SD] age, 79.9 [9.1] years) living in geriatric healthcare facilities for the elderly. BPSD and the burden on caregivers were measured over three weeks using the CMAI (Cohen-Mansfield Agitation Inventory), NPI-NH (Neuropsychiatric Inventory-Nursing Home Version) and J-ZBI (Modified Japanese Version of the Zarit Caregiver Burden Interview) at the end of each week. During the second week, the subjects received either 12,000 K (white) or 2,400 K (orange) of light corresponding to approximately 2,000 lux from a light-emitting diode (LED) device, measured before the eyes in the gaze direction, from 9 : 00 to 9 : 30 during occupational tasks, such as origami and coloring. Differences in the variables obtained at the different weeks were assessed using ANOVA with multiple comparisons. The scores for the severity of BPSD, including sleep disturbances and the burden on caregivers, on the NPI-NH significantly (P<0.05) improved following the treatment with white light exposure, while the scores for the MMSE and J-ZBI did not change over the three-week study period. These results suggest that exposure to white bright light during occupational tasks in the morning may have a benefit in improving BPSD, including sleep disturbances and the burden on caregivers.