Thought to be a result of its impact on the circadian rhythm, bright lighting may improve symptoms of dementia in the elderly. Not only that, but symptoms of depression were also positively impacted. From the article:
In an effort 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 subjects already presented with dementia. The trial examined 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.
In six of the facilities, bright lighting was installed on ceiling fixtures. The lights were turned on every day between nine in the morning and six in the evening. The participants were a part of this trial for an average of 15 months, with a maximum period of 3.5 years. It was found that the bright light had a positive effect on cognitive deterioration by 5% relative to those without the light, while depressive symptoms were reduced by 19%. The increase in functional limitations usually experienced by those with dementia was decreased by a relative 53%.
This looks to be an interesting finding. Of course, additional lighting has already been found to be effective in the treatment of seasonal affective disorder (SAD), so there may be some overlap between the two conditions, at least with respect to mood. Helping people regulate their circadian rhythms, sleep cycles, etc. can also be an effective way to improve overall functioning, and this may be especially true for the elderly, who often sleep more frequently, but less consistently. It’ll be interesting to see if these findings can be replicated, and if so, how we can take advantage of it.