Bright Light Improves Dementia Symptoms
Study Shows Brighter Daytime Lighting Brings Improvement in Mood, Behavior
June 10, 2008 -- Turning up the lights during the daytime may boost mood and
improve behavior in elderly adults with dementia, according to a new study.
Mood swings, sleep problems, and behavioral issues frequently affect those
with dementia-related cognitive decline. Such disturbances can increase the
person's risk of being admitted to an assisted living facility, according to background
information in the journal article.
Environmental light affects the body's 24-hour biological clock, also known
as the circadian rhythm. Too little light exposure can throw off the sensitive
balance of the circadian timing system. Disturbances in circadian rhythm can
lead to sleep woes. A hormone called
melatonin also plays an important role in the maintaining the system's
Rixt F. Riemersma-van der Lek, MD, of the Royal Netherlands Academy of Arts
and Sciences, Amsterdam, and colleagues wanted to see how bright light with or
supplements would effect symptoms of dementia and sleep disturbances.
Their study is published in the June 11 issue of The Journal of the
American Medical Association.
The study included 189 adults about 86 years old on average, mostly female,
at 12 elder care facilities in the Netherlands. Most participants had dementia.
Researchers randomly assigned the participants to a daily dose of melatonin or
placebo (fake pill). The patients took the study medicine every night for an
average of 15 months.
The facilities kept their lights on each day from about 9 a.m. to 6 p.m.;
half of the facilities increased the intensity of their ceiling-mounted
The researchers learned that bright light resulted in a modest improvement
in dementia symptoms. Specifically, the use of bright daytime lighting:
- Reduced cognitive decline on a mental status exam by a relative 5%.
- Cut depression
symptoms by a relative 19%.
- Calmed slow increases in functional limitations by slightly more than half
Adding melatonin helped patients fall asleep about eight minutes faster and
sleep longer by 27 minutes. The researchers recommend melatonin supplements
only in combination with light. Melatonin combined with brighter lighting cut
agitated behavior by 9%.
"The simple measure of increasing the illumination level in group care
facilities [improved] symptoms of disturbed cognition, mood, behavior,
functional abilities, and sleep," the researchers write. "The long-term
application of whole-day bright light did not have adverse effects ... and
could be considered for use in care facilities for elderly individuals with