Lighting intervention improves sleep, mood in dementia
The use of a tailored lighting intervention (TLI) improves sleep disturbances, mood, and agitation among patients with Alzheimer’s disease and related dementia (ADRD), according to a Lighting Research Center (LRC) study presented at AAIC 2018.
“TLI [was] designed to deliver high levels of circadian stimulus [CS] to the eyes of ADRD patients living in long-term care facilities [that] could improve their sleep and behaviour,” said lead author Dr Mariana Figueiro from LRC in Troy, New York, US. “Exposure to a CS of ≥0.3 at the eye, for at least 1 hour early in the day, has been associated with better sleep and improved behaviour and mood.”
The cross-over study involved 43 patients with ADRD (n=31, female) who were randomized to either active (CS >0.3) or inactive TLI (CS <0.1) for a short-term intervention of 4 weeks, followed by a washout period of 4 weeks before crossing over to the other intervention. TLI utilizes specially-designed LED light table and room lighting, which were installed in areas where patients spent most of their waking hours, and lighting was left on until 6:00 in the evening. Patients were given the Daysimeter to measure their light exposure. PSQI*, CSDD**, and CMAI*** scores were assessed for sleep disturbances, mood, and agitation conditions, respectively, before and after the intervention. [AAIC 2018, abstract 0295]
After the intervention, patients exposed to active TLI had significantly improved sleep quality from baseline as reflected by a greater reduction in PSQI scores than those on inactive TLI (mean score, from 10.3 to 6.7; p<0.0001 vs from 9.9 to 8.5; p<0.05).
Patients on active TLI also showed significant reduction in depressive symptoms from baseline, as shown by a greater reduction in CSDD scores compared with inactive TLI (mean score, from 10.5 to 7.3; p<0.01 vs from 11.1 to 9.8) after the intervention.
In addition, a significant improvement in agitation after the intervention was observed in the active TLI group compared with the inactive TLI group, as assessed by CMAI scores (mean score, from 42.9 to 37.4; p<0.01 vs from 42.7 to 41.5).
“This study provides support for the use of a TLI … When carefully delivered to patients’ eyes and monitored with a calibrated instrument, daytime light can improve sleep, mood, and agitation in persons living with dementia,” said Figueiro. “[In addition,] the TLI treatment holds considerable promise as a novel, practically applied, [and] non-pharmacological intervention for treating people with ADRD who live in long-term care”.
“[Furthermore,] a logical next step would be to test the short- and long-term effects of the TLI among those living at home, [and] a 6-month application of this same TLI is currently being tested in a long-term care setting as part of another arm of this study.,” Figueiro added.
*PSQI: Pittsburgh Sleep Quality Index
**CSDD: Cornell Scale for Depression in Dementia***CMAI: Cohen-Mansfield Agitation Index