Can light therapy be beneficial for Alzheimer's patients?

1 answer | Last updated: Sep 14, 2017
Aleenagk asked...

I found this interesting quote today: "Clinical research has shown that exposure to very bright light in the day and darkness at night can consolidate rest and activity patterns in AD patients.2 This clinical research was based on more basic studies of circadian regulation by light exposure in animals and humans.3,4 This large and growing body of research shows that bright light during the day is a powerful means of entraining natural circadian rhythms in all species, including humans. Depending on the timing, duration, intensity, and spectrum of the light, circadian rhythms can be synchronized or desynchronized (phase advanced or phase delayed) with the natural, 24-hour, daylight/darkness pattern." Source:

I would like to know whether exposure to full spectrum lighting conditions during the day time can prove beneficial for patients suffering from Alzheimer's disease?

Expert Answers

Ladislav Volicer, M.D., Ph.D., is recognized as an international expert on advanced dementia care. He is a courtesy full professor at the School of Aging Studies, University of South Florida, Tampa, and visiting professor at the Third Medical Faculty, Charles University, Prague, Czech Republic. Twenty-five years ago, he established one of the first dementia special care units.

There is good evidence that the circadian rhythm is disturbed in Alzheimer's disease. While in normal aging the period get shorter and, therefore, elders go to sleep earlier and wake up earlier, in Alzheimer's disease the circadian period gets longer. That may be why some Alzheimer patients suffer from sundowning - behavioral disturbances in the afternoon and evening. Bright light in the morning may delay the circadian phase and may help some patients. However, there is no complete agreement about that. There is one study from the Netherlands that indicated that providing more light during the day also decreases behavioral symptoms of dementia.