Bright daytime lighting, melatonin may help people with dementia

Caregivers of people with dementia have a very difficult job. Doctors are often looking for ways to make that job—and the life of people with dementia—easier. A new study suggests that increasing the brightness of light surrounding people with dementia may decrease the symptoms of dementia, and that the supplement melatonin may help them sleep better. Below, my colleague Dr. Robert Shmerling comments on this new study.

Could better lighting help with symptoms of dementia?

This may seem like an odd question to ask, but people with dementia often have trouble with circadian rhythms—the body's 24-hour cycle of wakefulness, sleep, and hormone fluctuations. For example, people with dementia often nap during the day. Then they have trouble sleeping at night. This can put a big strain on family, friends, and nursing home staff.

A possible explanation for this problem is abnormal levels of the hormone melatonin. The pineal gland, a small gland in the brain, makes melatonin in response to light signals from the eye. Changing cycles of light and dark could restore normal rhythms of melatonin production. Taking melatonin supplements might do the same thing. 

A study just published in the Journal of the American Medical Association tested this theory. Researchers in the Netherlands studied 189 elderly people. Most of them had dementia. Some received daily "doses" of bright lights being on from 9 a.m. to 6 p.m. Some took melatonin supplements (2.5 milligrams each night). Some had both treatments. Others had neither.

The average treatment period was 15 months. In this period, people who had bright lights on during the day had the following benefits:

·         A 5% decrease in the decline of thinking and memory

·         A 20% decrease in symptoms of depression

·         A 53% decrease in functional decline

Those receiving melatonin supplements:

·         Fell asleep 19% faster

·         Slept longer (by 6%) and with fewer interruptions (by 25%), but

·         Were more likely to have a depressed mood

People who received both melatonin and light treatment showed less aggressive behavior. Light treatment also seemed to counter the negative effects of melatonin on mood.

This study could be important for people with dementia and for their caregivers. Use of bright lights is a simple, safe change that could improve quality of life for people with dementia and also help those who care for them. 

Melatonin might be worth a try for a person with dementia. It would be most likely to help if sleep or aggressive behavior is a problem. In other situations, it's not clear that melatonin would be worthwhile. It does have potential risks. These include rare allergic reactions, abnormal blood clotting, or sleepiness. This study suggests that melatonin should be given along with light treatment. This may head off any negative effects on mood.

Changes to make now

If someone close to you has dementia, talk to his or her health care providers about the results of this study. Consider light treatment, melatonin, or both. As with any new treatment, though, close monitoring is important.

Julie K. Silver, M.D., is an assistant professor in the Department of Physical Medicine and Rehabilitation at Harvard Medical School. She is also the Chief Editor of Books for Harvard Health Publications.

Mental Health Letter
The field of mental health is rapidly evolving, and whether your interest is professional or personal, staying informed about these mental health issues is no easy job. The Harvard Mental Health Letter is a source of mental health news you can trust—and it comes directly from the more than 8,000 doctors and researchers at Harvard Medical School.

Are you Living With Insomnia? Connect with others with similar health concerns and issues. Click here to join the group.

This content is not intended to substitute for personalized medical advice, diagnosis, or treatment from your healthcare provider. Read our full disclaimer.