According to a new study done by Dutch scientists, exposure to bright light during daytime could improve mood and behavior in elderly patients with dementia.

People suffering from dementia also suffer from additional disturbances such as mood swings, sleep and behavioral problems, which increases their risks of being admitted to an assisted living facility.

Environmental daylight has a huge impact on the body's 24-hour biological clock, also known as the circadian rhythm. Not exposing to daylight enough can throw off the sensitive balance of the circadian timing system, which could additionally cause sleeping woes.

Melatonin, a hormone produced in the dark, also plays an important role in the maintaining the system's circadian rhythm.

The Dutch researchers decided to test how bright light with or without melatonin supplements affected symptoms of dementia and sleeping problems.

They included 189 adult participants who were about 86 years old, mostly female, at 12 elderly care facilities. Most participants suffered from dementia. The study participants were randomly assigned to a daily dose of melatonin or placebo that they had to take every night for an average of 15 months.

The lights were on each day from about 9 a.m. to 6 p.m. and half of the facilities increased the intensity of their ceiling-mounted lights.
The study results revealed that bright light resulted in a modest improvement in dementia symptoms. It reduced cognitive scores on a mental status exam by a relative 5%, cut depression symptoms by a relative 19%, and calmed slow increases in functional limitations by slightly more than half (53%).

The group that received melatonin supplements had improvement is sleep quality. Melatonin helped them fall asleep about eight minutes faster and sleep longer by 27 minutes. The researchers recommend melatonin supplements only in combination with light. This combination therapy cut agitated behavior by 9%.

Researchers reported that increasing illumination should be considered in care facilities for elderly individuals with dementia in order to improve symptoms of disturbed cognition, mood, behavior, functional abilities, and sleep.