Evidence: Dynamic light

Presented this week in Chicago, this paper shows how dynamic light that provides a high circadian stimulus during the day, and low circadian stimulus at night can lead to significantly decreased sleep disturbances, depression and agitation in participants with Alzheimer’s disease and related dementias compared with baseline. Furthermore, the positive effects observed in the short-term study continued to improve over the course of the 6-month, long-term lighting intervention.

Our circadian solutions are designed to deliver this variation in circadian stimulus automatically.

Monitored light intervention helps improve sleep in Alzheimer’s disease

Image of Mariana Figueiro

Mariana G. Figueiro

Daytime light — when carefully delivered and tailored to individual patients’ eyes and monitored with a calibrated instrument — can improve sleep, mood and agitation in nursing home residents with Alzheimer’s disease and related dementias, data presented at the Alzheimer’s Association International Conference revealed.

“The research is important because it is nonpharmacological,” Mariana G. Figueiro, PhD, director of the Lighting Research Center at Rensselaer Polytechnic Institute in New York, told Healio Psychiatry. “Being able to show the efficacy of a nonpharmacological treatment that helps Alzheimer’s disease patients sleep better, feel less depressed and improve their behavior is very much needed.”

Using a crossover, repeated-measures design, Figueiro and colleagues examined whether a tailored lighting intervention could improve sleep and behavior in patients with Alzheimer’s disease and related dementias living in long-term care facilities. Researchers exposed nursing home residents to alternating periods of lighting that provided either high- or low-circadian stimulus for 4 weeks (short-term study) and 6 months (long-term study, successive 4-week periods spaced by a 4-week washout), according to a press release.

The lighting intervention was added to places in which participants spent most of their time awake and was left on from wake time until 6:00 p.m. Calibrated personal light meters were used to monitor light exposures received in patients’ eyes. Using questionnaires, researchers assessed measures of sleep disturbances (Pittsburgh Sleep Quality Index), mood (Cornell Scale for Depression in Dementia) and agitation (Cohen-Mansfield Agitation Index) at baseline and during the last week of the intervention.

According to the release, 43 residents participated in the short-term study and 37 residents completed the long-term study. The results showed that the lighting intervention lead to significantly decreased sleep disturbances, depression and agitation in participants with Alzheimer’s disease and related dementias compared with baseline. Furthermore, the positive effects observed in the short-term study continued to improve over the course of the 6-month, long-term lighting intervention.

“Our study showed that light, when tailored to deliver the correct amount of circadian stimulus to the patient’s eyes, can be effective as an adjunct therapy to help Alzheimer’s disease patients sleep better, reduce their depression symptoms and agitation behavior,” Figueiro told Healio Psychiatry. “When properly prescribed and delivered, robust light-dark patterns can help Alzheimer’s disease patients improve sleep and behavior. But, it needs to be properly designed and delivered.” – by Savannah Demko

Reference:

Figueiro M, et al. Tailored lighting intervention to improve sleep, mood and behavior in Alzheimer’s disease patients. Presented at: Alzheimer’s Association International Conference; July 22-26, 2018, 2018; Chicago.

Disclosure: Figueiro reports no relevant financial disclosures.