How Does Alzheimer's Disease Affect Sleep? A HealthCentral Explainer

ATsai Editor
  • Alzheimer’s disease is a progressive brain disorder that affects memory, speech, thoughts and the ability to do daily tasks. The buildup of plaque, tangled fibers and loss of brain tissue leads to impaired mental ability. In early stages, loss of smell and disruptions to the sleep-wake cycle are common.


    What is the connection with sleep?

    A study reported in September used a mouse model to look at how plaques from Alzheimer’s affect sleep. The mice were genetically altered so that they would develop Alzheimer’s plaques as they aged.  Researchers focused on a protein called amyloid beta, which fluctuates in level in healthy people. They found that the amyloid beta levels stop changing in both mice and humans when the initial signs of plaque develop in the brain. Researchers hypothesize that the plaques are pulling the amyloid beta away from the normal process that would clear it from the brain.

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    The mice, which typically slept 40 minutes during every hour of daylight, began sleeping only 30 minutes as plaque began to appear on the brain. In a separate group of mice with the same altered genetics, a vaccine against amyloid beta was administered. These mice never developed brain plaque as they aged and their sleep behavior stayed the same. The amyloid beta levels in their brain continued to fluctuate normally.


    Scientists say that people who have not yet developed memory problems or other symptoms of the disease, but do have plaques in the brain, might experience sleep problems first.  This could help medical professionals treat Alzheimer’s before dementia sets in, because the prevalence or absence of sleep problems could indicate how treatment is working.


    [SLIDESHOW: 8 Health Issues That Cause Sleep Problems]


    How does sleep behavior change?

    People who have already been diagnosed with Alzheimer’s disease typically have different levels of sleep disruption based on the stage of their disease.

    According to the National Sleep Foundation, those in early stages of the disease will sleep more than usual, but wake up disoriented. As the disease progresses, people will sleep more during the day and wake up frequently during the night. In advanced disease, people will not be able to sleep for long periods, and rather will doze throughout the day and night. The body clock will also be disrupted, which can prevent the person from staying asleep or staying alert.


    In addition, people with Alzheimer’s disease can become agitated, particularly in the evening. This might be due in part to the sleep disruptions and resulting sleepiness.


         [SLIDESHOW: 10 Signs of Alzheimer’s Disease]


    What are treatment options for these sleep disruptions?

    Non-medication treatment options are best to try first, according to the Alzheimer’s Association, as sleep mediations can cause serious side effects.  Enforcing a strict schedule for meal times, bed times and wake times can help a person with Alzheimer’s sync with their body clock. Getting morning sunlight exposure can help wake them up. Daily exercise, but not four hours before bed can help tire them out.  Avoiding alcohol, caffeine and nicotine can help reduce sleep disruptions, and treating any pain before bedtime.


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    Other good sleep habits include, keeping the bedroom at a comfortable temperature, discouraging television and other devices with LED lights before bed and lying in bed awake. It’s better to get up and walk around than lay in bed awake.


    Sleep medication for those with Alzheimer’s disease can increase the risk for falls, confusion and a decline in the ability for self-care. If sleep medication is necessary, it should only be used until a regular sleep pattern is established.

    Speak to your doctor about the specific medications available, as which medication is prescribed will depend on the behaviors that accompany the sleep problems.



    n.p. (2012, November 8). “Alzheimer’s Disease Fact Sheet.” National Institute of Aging. Retrieved from


    n.p. (2012, September 6). "Sleep Problems May Be Early Indication Of Alzheimer's Disease." Medical News Today. Retrieved from


    n.p. “Alzheimer’s Disease and Sleep.” National Sleep Foundation. Retrieved from


    n.p. “Treatment for Sleep Changes.” Alzheimer’s Association. Retrieved from


Published On: November 26, 2012