Brightening the lights for elderly people with dementia, in combination with a daily dose of the sleep hormone melatonin, improved their mood, sleep, and overall well-being, Dutch researchers said on Tuesday.
"The strong point of our findings was that effects were so prominent over a wide range of measurements of different aspects of functioning, suggesting a very strong improvement of the quality of life," said Eus van Someren of the Netherlands Institute for Neuroscience, in Amsterdam.
Dementia patients who live semi-independently often deteriorate and are forced into nursing homes as they lose mental and physical faculties, become irritable, suffer frequent headaches and develop sleeplessness.
The study found exposure to bright light during daylight hours — from the sun through large windows and from added fluorescent fixtures — decreased mental deterioration by 5 percent compared to patients not exposed.
There was a 19 percent relative reduction in depressive symptoms, and 53 percent relative slowing of their loss of ability to cope with daily living over the 15 months of the study, they reported in the Journal of the American Medical Association.
Providing a daily dose of melatonin added to the beneficial effects, the researchers found. Melatonin is a hormone that helps control the body's circadian rhythm, which governs sleep schedules.
"Combined treatment (with light and melatonin) attenuated aggressive behavior, increased sleep efficiency and improved nocturnal restlessness" in patients, van Someren said in an e-mail response to questions.
The study took 189 mostly women residents of 12 group homes in the Netherlands and divided them into groups to examine the effects of brighter light exposure and melatonin.
The most surprising finding, van Someren said, was that light and melatonin improved mental functioning in Alzheimer's disease patients about as well as Alzheimer's drugs.
But the Alzheimer's drugs can cause side effects such as nausea.
The melatonin dosage used, 2.5 milligrams, may be too high as there were some adverse affects such as withdrawn behavior, the researchers said. However those problems were alleviated if light was included in treatment.
Previous studies of melatonin have not found much benefit to dementia patients, but the impact may take longer to manifest itself, van Someren said.