Use of bright lighting may improve dementia symptoms for elderly persons

June 10, 2008,

The use of daytime bright lighting to improve the circadian rhythm of elderly persons was associated with modest improvement in symptoms of dementia, and the addition of the use of melatonin resulted in improved sleep, according to a study in the June 11 issue of JAMA.

"In elderly patients with dementia, cognitive decline is frequently accompanied by disturbances of mood, behavior, sleep, and activities of daily living, which increase caregiver burden and the risk of institutionalization," the author write. These symptoms have been associated with disturbances of the circadian rhythm (the regular recurrence, in cycles of about 24 hours, of biological processes or activities). "The circadian timing system is highly sensitive to environmental light and the hormone melatonin and may not function optimally in the absence of their synchronizing effects. In elderly patients with dementia, synchronization may be [diminished] if light exposure and melatonin production are reduced."

Rixt F. Riemersma-van der Lek, M.D., of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, and colleagues conducted a trial at 12 elderly group care facilities in the Netherlands that evaluated the effects of up to 3.5 years of daily supplementation of bright light and/or melatonin on a number of health outcomes, including symptoms of dementia and sleep disturbances. The study included 189 facility residents, average age 85.8 years; 90 percent were female and 87 percent had dementia.

Six of the facilities had bright lighting installed in ceiling-mounted fixtures. Lights were on daily between approximately 9 a.m. to 6 p.m. Participants were randomized to receive evening melatonin (2.5 mg) or placebo and participated an average of 15 months (maximum period of 3.5 years).

The researchers found that bright light lessened cognitive deterioration by a relative 5 percent, reduced depressive symptoms by a relative 19 percent and diminished the gradual increase in functional limitations by a relative 53 percent.

Melatonin reduced the time to fall asleep by a relative 19 percent and increased total sleep duration by 6 percent, but adversely affected caregiver ratings of withdrawn behavior and mood expressions. The addition of bright light improved the adverse effect on mood. In combination with bright light, melatonin reduced aggressive behavior by a relative 9 percent.

"In conclusion, the simple measure of increasing the illumination level in group care facilities [improved] symptoms of disturbed cognition, mood, behavior, functional abilities, and sleep. 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 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," the authors write.

Source: JAMA and Archives Journals

Explore further: Preschoolers exposed to nighttime light lack melatonin

Related Stories

Preschoolers exposed to nighttime light lack melatonin

March 5, 2018
Exposing preschoolers to an hour of bright light before bedtime almost completely shuts down their production of the sleep-promoting hormone melatonin and keeps it suppressed for at least 50 minutes after lights out, according ...

Staying awake—the surprisingly effective way to treat depression

January 23, 2018
The first sign that something is happening is Angelina's hands. As she chats to the nurse in Italian, she begins to gesticulate, jabbing, moulding and circling the air with her fingers. As the minutes pass and Angelina becomes ...

Why getting enough sleep should be on your list of New Year's resolutions

December 27, 2017
If you need an alarm to get up in the morning, you're probably not getting enough sleep.

Light exposure in the evening improves performance in the final spurt

May 19, 2017
Athletes often have to compete late in the evening, when they are no longer able to perform at their best. As reported in the journal Frontiers in Physiology, however, researchers from the University of Basel have shown that ...

Bright light after night shift may enhance alertness and cognitive performance

June 11, 2015
A new study suggests that bright light at the end of a night shift may have potential as a countermeasure to improve driving performance, particularly for low light work environments and commutes that occur before dawn.

Light from electronic screens at night linked to sleep loss

July 11, 2012
Like a lot of Americans, Amalie Drury has grown very attached to her smartphone.

Recommended for you

Metabolite therapy proves effective in treating C. difficile in mice

March 20, 2018
A team of UCLA researchers found that a metabolite therapy was effective in mice for treating a serious infection of the colon known as Clostridium difficile infection, or C. difficile.

Sick air travelers mostly likely to infect next row: study

March 19, 2018
People who fly on airplanes while contagious can indeed get other people sick, but the risk is mainly to those seated next to them or in the adjacent row, US researchers said Monday.

Study of COPD patients has created a 'looking glass' into genome of pathogen

March 19, 2018
Decades of work on chronic obstructive pulmonary disease (COPD) at the University at Buffalo and the Veterans Affairs Western New York Healthcare System have yielded extraordinary information about the pathogen that does ...

Newly described human antibody prevents malaria in mice

March 19, 2018
Scientists have discovered a human antibody that protected mice from infection with the deadliest malaria parasite, Plasmodium falciparum. The research findings provide the basis for future testing in humans to determine ...

A multimodal intervention to reduce one of the most common healthcare-acquired infections

March 16, 2018
Surgical site infections are the most frequent health care-associated infections in developing countries. According to the World Health Organization (WHO), this type of infection can affect up to one-third of surgical patients ...

After infection, herpes lurks in nerve cells, ready to strike—New research reveals what enables the virus to do so

March 15, 2018
Once herpes simplex infects a person, the virus goes into hiding inside nerve cells, hibernating there for life, periodically waking up from its sleep to reignite infection, causing cold sores or genital lesions to recur.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.