Saturday, 2 January 2010


Many people with Alzheimer's have trouble sleeping, which can leave them exhausted during the day. Fatigue takes a toll on both patients and their caregivers. Indeed, irregular sleeping is a major reason why families move relatives with Alzheimer's into long-term care. Light therapy is a promising treatment under investigation for people with Alzheimer’s who struggle with sleep.

Alzheimer's patients who have trouble sleeping should first be evaluated for underlying sleep disorders and medical conditions that cause sleep trouble. Also, stopping medications that affect sleep or switching to more tolerable drugs may help.

No studies have found that conventional sleep aids, like Ambien (zolpidem) and Sonata (zaleplon), or sedative antidepressant medications like trazodone (Desyrel) effectively treat disturbed sleep in Alzheimer's patients. And supplements that boost levels of melatonin (a hormone that makes people feel tired) have limited effect, perhaps because Alzheimer's patients have fewer melatonin receptors in the brain than people without dementia.

Light therapy - regular exposure to sunlight or special bright lamps that mimic natural light - is another option. Exposure to bright light signals to the brain that it is daytime and helps set the body's circadian rhythms -- regular mental and biological changes that occur over a 24-hour cycle and regulate important functions, like preparing the body for sleep at night.

How well does light therapy work for Alzheimer’s patients? In a three-week study from the University of North Carolina at Chapel Hill, 66 adults with dementia living in long-term care facilities were exposed for varying amounts of time to bright ceiling lights installed in common areas.

Compared with participants who did not spend time under the lights, those who were exposed to light therapy for two and a half hours in the morning slept 16 minutes longer; those who were exposed for about eight and a half hours off and on throughout the day slept 14 minutes longer. The morning group was also able to fall asleep 29 minutes earlier, which is important since Alzheimer's patients often can't fall asleep until late at night.

But not all studies have produced positive results, and there are questions about the appropriate dosage. The amount of light prescribed for other conditions may not be sufficient for older patients with Alzheimer's; eyes transmit less light with age, and visual problems are particularly common in patients with Alzheimer's disease.

While researchers have yet to determine the ultimate benefits of light therapy or how much is needed to have an effect, "It's still reasonable to encourage people with Alzheimer's to stay in well-lit areas during the day," says Peter Rabins, M. D., Director of Geriatric Psychiatry and Neuropsychiatry at Johns Hopkins.

This may be more practical than purchasing specialized equipment, he notes. "The light-therapy boxes used by people with disorders like depression require sitting still in front of a bright lamp, and this can be a challenge for those with Alzheimer's." Spending time outside in the morning may be a convenient way to produce similar effects.

More Tips for Caregivers. The Alzheimer's Association offers these tips for better sleep:

  • Maintain regular meal times and sleep schedules.
  • Discourage alcohol, caffeine, and nicotine use.
  • Encourage daily exercise (but no later than 4 hours before bedtime)
  • Don't give Alzheimer's drugs before bedtime.
  • Discourage watching TV or staying in bed during wakeful periods.

(Source: John Hopkins Health Alerts, 14 December 2009)