Can Lighting Improve Sleep, Mood, and Behavior in Patients With Dementia?

BALTIMORE—Among patients with Alzheimer’s disease and related dementias, a lighting intervention may improve sleep, mood, and agitation, according to a study presented at the 32nd Annual Meeting of the Associated Professional Sleep Societies.

Mariana G. Figueiro, PhD

The intervention “holds considerable promise as a novel, practically applied, nonpharmacologic intervention” for people with dementia who live in long-term care facilities, said Mariana G. Figueiro, PhD, Director of the Lighting Research Center and Professor of Architecture at Rensselaer Polytechnic Institute in Troy, New York.

People with dementia often have problems related to sleep and daytime irritability. A study in office workers found that exposure to light that stimulates the circadian system early in the day is associated with better sleep and improved behavior and mood. To assess whether a lighting intervention that delivers a circadian stimulus may improve sleep and behavior in patients with dementia in long-term care facilities, Dr. Figueiro and colleagues conducted a crossover, repeated-measures, within-subjects study. The study included 43 subjects (31 female) with Alzheimer’s disease or related dementias and Mini-Mental State Examination scores of less than 24.

The intervention consisted of an LED light table and individual room lights that were placed where patients spent most of their waking hours. The lights were turned on when participants woke up and remained on until 6 PM. Participants wore calibrated light meters that monitored their light exposure.

The trial included four weeks with an active circadian stimulus, four weeks with an inactive lighting intervention, and a four-week washout period in between.

In addition, researchers collected subjective measures of sleep disturbances (Pittsburgh Sleep Quality Index [PSQI]), mood (Cornell Scale for Depression in Dementia [CSDD]), and agitation (Cohen-Mansfield Agitation Index [CMAI]) at baseline and during the last week of the active and placebo intervention periods.

The active lighting intervention significantly decreased scores for sleep disturbances, depression, and agitation, compared with placebo. During the active intervention, mean PSQI scores decreased from 10.3 to 6.7, CSDD scores decreased from 10.5 to 7.3, and CMAI scores decreased from 42.9 to 37.4.

A six-month study of the lighting intervention is underway. “A logical next step would be to test the short- and long-term effects of the tailored lighting intervention among those living at home,” Dr. Figueiro and colleagues said.

—Jake Remaly

Suggested Reading

Figueiro MG, Steverson B, Heerwagen J, et al. The impact of daytime light exposures on sleep and mood in office workers. Sleep Health. 2017;3(3):204-215.