Bright Light Can Help Treat Dementia Symptoms
Melatonin should only be used together with light to reap benefits and avoid adverse effects
TUESDAY, June 10 (HealthDay News) -- Bright light can be used to treat patients with dementia and has a modest positive effect on some cognitive and non-cognitive symptoms, but melatonin should be used only in combination with lights to counteract its negative impact on mood, according to a report published in the June 11 issue of the Journal of the American Medical Association.
Rixt F. Riemersma-van der Lek, M.D., of the Royal Netherlands Academy of Arts and Sciences in Amsterdam, the Netherlands, and colleagues conducted a study of 189 residents of 12 group-care facilities. The subjects were randomized to treatment with whole-day bright or dim light and 2.5 mg of evening melatonin or placebo for a maximum of 3.5 years.
Bright light attenuated cognitive deterioration as well as the increase of functional limitations over time, and also improved depressive symptoms, the investigators found. Although melatonin shortened the time it took to get to sleep and increased duration of sleep, when used without bright light it also increased withdrawn behavior. Used in combination, bright light and melatonin attenuate aggressive behavior, increased sleep efficiency and improved nocturnal restlessness.
"Melatonin improved sleep, but its long-term use by elderly individuals can only be recommended in combination with light to suppress adverse effects on mood," the authors write. "The long-term application of whole-day bright light did not have adverse effects, on the contrary, and could be considered for use in care facilities for elderly individuals with dementia."