Bright Light Shown to Lift Spirits of Dementia Patients

Since the early 1980s, bright light therapy has been used as an effective treatment for a number of disorders, such as seasonal affective disorder (SAD), premenstrual syndrome (PMS), as well as sleep disorders associated with shift work and jet lag, without long-term side effects. Recently, researchers discovered that bright lights, in combination with daily doses of melatonin (a hormone that governs sleep), brought modest improvement in symptoms of dementia, equal to or surpassing that of commonly prescribed medications.

People suffering from dementia often go through difficult stages as the disease progresses; memory and other cognitive problems, depression, aggression, agitation, delusions, hallucinations, and sleep disturbances, often forcing them into nursing homes. The anti-psychotic drugs often prescribed to treat behavioral symptoms have been found to increase the risk of hospitalization and even death.

For the study, Rixt F. Riemersma-van der Lek, M.D., of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, and colleagues evaluated the effects of brighter light exposure and melatonin on 189 residents, mostly women, at 12 elderly group care facilities in the Netherlands. Six of the facilities were equipped with bright lighting (1,000 lux) installed in ceiling-mounted fixtures, which were on daily between 9 a.m. to 6 p.m. Study participants were randomly divided into groups to receive either melatonin (2.5 mg) or a placebo in the evening over a 15-month period. Their progress was evaluated every six months.

The researchers found that exposure to bright light decreased memory loss in dementia patients by 5 percent and reduced depressive symptoms by a relative 19 percent. But the largest improvement by far was the 53 percent slowing of their daily functional limitations, such as their ability to carry out ordinary tasks including dressing, bathing and eating. The addition of melatonin reduced the time to fall asleep by 19 percent, increased mean sleep duration by 25 percent, and decreased aggressive behavior by 9 percent. However, according to caretakers, melatonin adversely affected mood expressions and withdrawn behavior. Adding bright light improved these adverse effects. The authors speculated that the dose of melatonin was too high and that a lower dose should be considered.

"The strong point of our findings was that effects were so prominent over a wide range of measurements of different aspects of functioning, suggesting a very strong improvement of the quality of life," said senior author Eus van Someren of the Netherlands Institute for Neuroscience, in Amsterdam, according to Thomson Reuters.

The Dutch study is reported in the June 11 issue of the Journal of American Medical Association.