As a person ages, their sleep patterns typically change, and they can find it more challenging to fall asleep. However, sleep changes related to Alzheimer’s are more complex.

Alzheimer’s disease causes progressive, irreversible memory loss and affects how individuals think, reason, and behave. It is the most common type of dementia.

As Alzheimer’s progresses, it may lead to sleeping problems that disrupt the person’s daily routine and that of their caregivers. The person may experience various sleep disturbances, including shorter or fragmented sleep, changes to their sleep cycle, and sleep disorders.

This article looks at how and why Alzheimer’s affects sleep. It also provides some sleep management tips that may help with sleep issues relating to Alzheimer’s.

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People with Alzheimer’s may experience a range of sleep disturbances, including restless sleep at night and excessive daytime sleepiness.

Experts do not fully understand why Alzheimer’s affects sleep. The relationship is complex, and sleep disturbances may precede the cognitive decline that occurs in people with Alzheimer’s.

Circadian rhythm

Researchers believe Alzheimer’s causes cellular changes in the brain, disrupting the sleep-wake cycle. The body’s circadian rhythm controls this cycle. Changes in the production of melatonin, the sleep hormone, also affect sleep.

The suprachiasmatic nucleus (SCN) is an area of the brain that serves as an internal body clock, driving the circadian rhythm. It responds to light cues that help determine when people are awake and alert and when they feel sleepy.

Experts believe individuals with Alzheimer’s disease may also have damage to the cells in their SCN, causing dysregulation of the sleep-wake cycle.

Brain proteins

The sleep changes in people with Alzheimer’s may relate to a protein called beta-amyloid, a waste product that can build up in the fluid between neurons (nerve cells) in the brain.

Doctors link increases in this protein with impaired brain function. In Alzheimer’s disease, beta-amyloid sticks together, forming amyloid plaques that interfere with communication between brain cells.

Beta-amyloid and sleep

Some studies suggest the brain clears excess beta-amyloid from the brain during sleep. For example, research shows that sleep deprivation causes elevated brain beta-amyloid levels among mice. However, at present, there is a lack of research involving humans.

In one 2018 study, researchers performed PET scans of the brains of 20 healthy participants ages 22 to 72 after a full night’s sleep and after about 31 hours without sleep.

They found that beta-amyloid levels in the brain increased by about 5% following sleep deprivation. The changes happened in the thalamus and hippocampus, which are particularly vulnerable to damage from Alzheimer’s. This may suggest a lack of sleep could contribute to Alzheimer’s.

Tau protein

Alzheimer’s also involves a brain protein called tau, which helps regulate healthy signaling between neuronal cells.

People with Alzheimer’s disease have tangles of tau protein in their brains, indicating damage to nerve cells. As little as one night of sleep deprivation can increase tau levels by as much as 50% in cerebrospinal fluid.

The relationship between beta-amyloid, tau, and Alzheimer’s is complex. Experts understand that high quality sleep allows an individual to clear excess brain proteins, but remain unsure whether sleep disruption prompts Alzheimer’s, aggravates symptoms, and causes disease progression or whether sleep disruption is a consequence of the disease.

People with Alzheimer’s and other forms of dementia often sleep for long periods and may need to sleep during the day.

As Alzheimer’s progresses, it causes an increasing amount of damage to the brain, and the individual often has less energy and begins to lose self-care abilities. A person may feel exhausted after everyday tasks, such as communicating, eating, or trying to make sense of the world around them. People may sleep more during the day as the symptoms worsen.

Additionally, medications that doctors prescribe to treat Alzheimer’s can contribute to sleepiness. These medications may include the following:

Treatment options for sleep schedule disruptions due to Alzheimer’s may include:

  • maintaining regular routines for meals, going to sleep, and waking up
  • getting morning sunlight exposure
  • getting regular exercise no later than 4 hours before going to sleep
  • effectively treating pain, which may make sleep more difficult
  • making sure the bedroom is a comfortable temperature
  • having nightlights and other security objects
  • only using the bed for sleep

Things to avoid:

To improve sleep, it may also help to avoid the following:

  • alcohol, caffeine, and nicotine
  • taking certain medications, such as cholinesterase inhibitors, before bedtime
  • watching television during periods spent awake

Generally, it is also advisable for those living with Alzheimer’s to avoid taking sleep medications. However, a doctor may recommend these for a short period if sleep problems are severe and other treatments have not helped.

Examples of the medications a doctor may suggest include:

Learn more about sleep hygiene.

Alzheimer’s can result in a reduction in sleep quality due to the following factors:

People with Alzheimer’s may have difficulty communicating to their caregivers that something is wrong. For example, they may be unable to tell someone that they are experiencing pain. In this case, the pain may impair their sleep.

Memory loss is the leading symptom of Alzheimer’s, and getting sufficient deep sleep and rapid eye movement (REM) sleep is necessary for memory preservation. People with Alzheimer’s progressively experience shorter durations of deep sleep and REM sleep.

Alzheimer’s effects on sleep may also lead to decreased physical activity, which usually means spending less time in natural sunlight.

People with Alzheimer’s may wish to try sleeping on their side rather than on their back or stomach. A 2019 study notes a potential association between sleeping on the back and neurodegenerative conditions, such as Alzheimer’s.

This may be due to the glymphatic system, a system for waste clearance in the central nervous system (CNS). The glymphatic system likely plays an important role in effectively removing waste products in the brain that contribute to Alzheimer’s disease, such as beta-amyloid.

Evidence suggests that sleeping on the side may help support the glymphatic system and protect against Alzheimer’s. However, further research is still necessary to understand glymphatic dysfunction and its potential role in the development of neurodegenerative conditions.

Caregivers of people with Alzheimer’s can take steps to help them manage their sleep, including:

  • Identifying any other medical conditions: An individual may have another condition that causes them to wake up. For example, sleep apnea causes short pauses in breathing, and restless legs syndrome involves moving or twitching the legs uncontrollably.
  • Reviewing medications: The side effects of some prescription medications that treat Alzheimer’s may contribute to sleepless nights. A doctor can advise on the best time of day to take medications to ease these effects.
  • Keeping a clock visible: It may be beneficial for the individual to be able to see a clock to help them distinguish between nighttime and daytime.
  • Talking with them: If the individual gets up in the night, a caregiver can speak with them to try to find out why. It is best to try to keep the person relaxed and prepare them for returning to sleep, for example, with low lighting and relaxing music they enjoy.
  • Using a bed exit pad: These wireless pads signal if the individual wanders from their bed during the night. Once a caregiver receives the alert, they can assist the individual in getting back into bed as soon as possible.
  • Establishing a routine: Keeping the same bedtime and wake time each day and implementing a bedtime routine, such as a relaxing bath or a hot, milky drink before sleep, can help the individual recognize the time of day.

Alzheimer’s disease is the seventh leading cause of death in the United States, contributing to more deaths than breast cancer and prostate cancer combined.

Alzheimer’s is a progressive condition. The average life expectancy following diagnosis is 4 to 8 years, but each person’s outlook will depend on individual factors. The person and their caregivers will need support to help them navigate the condition.

Various treatments can address Alzheimer’s symptoms and help an individual manage sleeping difficulties.

Learn more about the stages of Alzheimer’s here.

Below are answers to some common questions about Alzheimer’s and sleep.

Why do those with Alzheimer’s not sleep at night?

It is not fully known why Alzheimer’s affects sleep. However, experts believe that multiple factors, such as a disruption of circadian rhythm and an accumulation of certain brain proteins, likely result in sleep disturbances that can prevent a person with Alzheimer’s from sleeping at night.

Do people with Alzheimer’s sleep more?

Many different aspects of Alzheimer’s disease, as well as medications to treat the condition, can result in exhaustion and sleepiness. As such, many people with Alzheimer’s often sleep for long periods.

What can help treat sleep changes due to Alzheimer’s?

To help treat sleep changes, a person can try to improve sleep hygiene. This refers to lifestyle changes such as maintaining a routine before bedtime and reserving the bed for only sleep. In more severe cases, a doctor may recommend medication. However, a person should only use these in the short term and in the manner a doctor prescribes.

Alzheimer’s and dementia resources

To discover more evidence-based information and resources for Alzheimer’s and dementia, visit our dedicated hub.

Alzheimer’s disease is a form of dementia that can lead to sleeping issues. Experts also think that sleeping issues may contribute to an individual developing Alzheimer’s.

The relationship between Alzheimer’s and sleep issues is complex and may encompass cellular changes in the brain that upset the typical circadian rhythm. Sleep issues may also involve changes in melatonin production and a buildup of the proteins beta-amyloid and tau in the brain.

Although sleep issues can be challenging to manage, caregivers can take various steps to help an individual with Alzheimer’s sleep better. These include putting a nighttime routine in place and discussing the best time of day to take medications with a doctor.