A optimal improvement in dementia symptoms has been linked with the use of bright light in daytime, for the improvement of their circadian rhythms, according to a study released on June 10, 2008 in JAMA. More over, the melatonin is also helpful in improving sleep.
Dementia is a costant decline in cognitive ability with the passage of time, and usually elderly patients suffer from this condition. These symptoms can have many contributing factors, according to the authors: “In elderly patients with dementia, cognitive decline is frequently increase by disturbances of mood, behavior, sleep, and activities of daily routine life, which enhance caregiver burden and the risk of institutionalization.”
Several biological processes in many organisms recur within 24 hours that is referred as a circadian rhythm. Although this rhythm is internal but it can be affected by various factors including the presence or absense of daylight. In humans, melatonin levels considered to be the yard stick in measuring the circadian cycle, and sometimes melatonin is used to maintain a regular rhythm. Abnormalities of imbalanced rhythms are quite familiar which include jet lag and Seasonal Affective Disorder (SAD.)
According to the authors, the circadian rhythm can also be
linked with the symptoms of dementia in the elderly stage: “The circadian timing system is extremely sensitive to environmental light and the melatonin hormone may not function properly in the absence of their synchronizing effects. In elderly patients with dementia, synchronization may be abolished if light exposure and melatonin production is reduced from certain level.”
In an experiment to evaluate the effects of circadian rhythm modification on dementia, Rixt F. Riemersma-van der Lek, M.D., of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, and colleagues performed a trial in 12 different elderly group care facilities on 189 facility residents with an average age of 85.8 years. Of the total, 90% were female, and 87% of the people were already suffering with dementia. The trial noticed the effects of up to 3.5 years of daily supplementation with bright light and/or melatonin on several different health outcomes, including dementia and sleep disturbances.
Out of the six facilities, bright lighting was installed on ceiling fixtures. The lights were turned on every day from 9 a.m to 6 p.m. Researchers came to know that the bright light had very positive effect on cognitive deterioration by 5% as compare to those without the light and depressive symptoms were reduced by 19%. The increase in functional abilities usually experienced by those in which dementia was reduced by 53%.
In addition, randomly, patients were choosen to receive evening melatonin doses (2.5 mg) or a placebo. Patients using melatonin had a reduced time needed to fall asleep by 19%, and their average total sleep durations increased by 6%. However, caregiver ratings dropped due to withdrawn behavior and mood expression.
In combination with bright light, melatonin administration have synergistic effects in reduceding aggressive behavior by 9% relative to those without it and a mood elevator.
In conclusion, simpley increasing the illumination level in group care facilities can minimize symptoms of disturbed cognition, mood, behavior, functional abilities, and sleep. Although melatonin improves sleep, but its long-term use by elderly individuals can only be recommended in combination with bright light to put down adverse effects on mood.