Sleep disorders, like insomnia and excessive daytime sleepiness, are common among people with dementia. Symptoms may worsen as dementia progresses.

When you or a loved one has dementia, you may notice that sleeping is more challenging than it used to be. It’s not your imagination. It’s a common side effect of the condition.

However, people with dementia can take steps to improve their sleep and get more of the rest they need. More rest can translate to fewer accidents and falls and a better mood overall.

Here’s why dementia affects sleep and what you can do about it.

Sleep quality often declines in people ages 55 and older, and dementia can make it worse.

Dementia changes the way your brain functions and the way it regulates sleep. Most adults need 7 to 8 hours of sleep each night, but dementia can make it hard to get that amount. Or, you may get too much sleep at the wrong time.

Dementia interferes with your body clock, which regulates your sleep based on the amount of natural light present and your routine daily activities. Dementia also makes you less sensitive to sleep pressure, the need to sleep after you’ve been awake.

Your body clock and sleep pressure usually work together to help you get good, regular sleep. But in dementia, these functions don’t work right, and sleep difficulties happen.

How common are sleep disorders in people with dementia?

A 2023 review found that 26% of people living with dementia experience some type of sleep disorder.

An earlier, larger review found that 38% of people with dementia experienced disturbed sleep.

Was this helpful?

How dementia affects your sleep may depend on the type of dementia you have. Some of the common dementia types linked to sleep disorders include:

According to a 2023 review, sleep disturbances were most common in people with LBD, affecting about half. In contrast, about one-third of people with FTD or vascular dementia and one-quarter of people with Alzheimer’s reported sleep disturbances.

Research links the above dementias to several sleep disorders, including:

Let’s explore some of these in greater detail.

Being sleepy during the day is common among older adults, especially those with certain types of dementia.

A 2019 study found that people with LBD were more than twice as likely to experience daytime sleepiness than people with Alzheimer’s or FTD.

Excessive daytime sleepiness is often due to poor nighttime sleep. Furthermore, daytime sleepiness can cause people with these conditions to take more naps during the day, making it even harder to sleep at night.

Expert recommendations for managing daytime sleepiness include:

  • daytime physical activity
  • melatonin
  • adjusting medication

Dementia and prolonged sleep

Research from 2017 suggests that oversleeping at night (regularly more than 9 hours) may be an early sign of dementia.

Oversleeping at night is sometimes due to excessive daytime sleepiness or hypersomnia.

Was this helpful?

People with dementia often experience insomnia, a common sleep disorder that makes it hard to fall asleep, stay asleep, or both. Insomnia can make you anxious, irritable, depressed, or lacking in energy. It can also make it hard to concentrate.

Causes of insomnia in people with dementia include:

  • other health concerns, such as breathing or urinary problems
  • mental health conditions like depression or anxiety
  • pain
  • medication side effects

Doctors can try to find and treat the underlying cause of insomnia. They may also recommend:

Scientists estimate that 70% to 80% of people with dementia have sleep apnea, a condition in which your breathing stops and starts during sleep. Sleep apnea also seems to worsen as dementia progresses. It can also contribute to insomnia and daytime sleepiness.

Managing sleep apnea typically involves using a continuous positive airway pressure (CPAP) machine. In addition to improving mood and sleep, CPAP may also improve cognition in people with dementia, according to 2023 research.

REM is the phase of sleep in which dreaming typically occurs. Getting enough REM sleep is key to feeling well-rested. In REM sleep behavior disorder (RBD), your muscles don’t relax as they should, and you can act out movements from your dreams, including flailing, punching, or kicking.

RBD is rare, affecting about 1% of people. But it’s much more common in people with dementia, especially LBD.

In addition to taking melatonin, safeguarding the room in which you sleep can be helpful. Experts also recommend avoiding antidepressants, caffeine, and chocolate. A doctor may also prescribe clonazepam (Klonopin).

Tips for better sleep with dementia

  • Treat underlying conditions.
  • Stay engaged with fun activities.
  • Get plenty of natural light.
  • Stay active during the day for better rest at night.
  • Stay away from caffeine, cigarettes, and alcohol.
  • Cut down on screen time near the end of the day.
  • Relax at bedtime.
  • Practice good sleep habits (also called sleep hygiene).
  • If you’re a caregiver having trouble sleeping, consider hiring a night sitter.
Was this helpful?

Sundowning, or “sundowner’s syndrome,” is the name for a group of symptoms that affect some people with dementia in the late afternoon and into the night. Researchers don’t know what causes it, but it’s likely related to dementia-related changes in the brain.

Sundowner’s syndrome can cause you to be angry, yell, do or say inappropriate things, or experience agitation, usually in the evening or later.

Symptoms of sundowning include:

  • confusion
  • agitation
  • restlessness
  • hallucinations
  • insomnia
  • pacing
  • wandering
  • yelling

The best way to manage sundowning is to find and treat the underlying cause, practice good sleep habits, and plan around it. Experts, like the National Institute on Aging and the Alzheimer’s Association, suggest the following:

  • Schedule important appointments for earlier in the day.
  • Avoid creating too full a schedule.
  • Create a calm environment.
  • Make early evening relaxing.
  • Make lunch heavier and dinner lighter.
  • Take a walk.
  • Discuss the problem with your doctor.

Does poor sleep cause dementia?

Poor sleep may have a causal link to dementia.

A 2023 study found that adults over 65 with insomnia had a 51% higher risk of developing dementia. The study’s authors cited several previous studies that also found a link between poor-quality sleep and the risk of developing dementia.

For example, a 2017 study found a link between sleep disturbances and the buildup of beta-amyloid plaques in young adults. Such buildup is common in the brains of people with Alzheimer’s.

Was this helpful?

Right now, there’s no cure for dementia and the sleep problems it causes. Specific sleep symptoms and their severity may depend on the type of dementia. For example, excessive daytime sleepiness is especially more common among people with Lewy body dementia.

You can take steps to improve your sleep quality and make it easier to fall asleep. Treating the underlying cause is the most important thing you can do, followed by lifestyle changes that promote good sleep habits.