Waking Up to the Link Between Sleep and Dementia

August 12, 2022

“Sleeping like a baby” is the gold standard in slumber, and for good reason. As we age, getting the recommended 7 or more hours of sleep per night becomes increasingly difficult.

In fact, over a third of American adults are sleep deprived, a problem that’s hit an all-time high during the pandemic. Even during relatively normal times, older adults experience decreased overall sleep time, more difficulty falling and staying asleep, less time in deep sleep, and other complicating factors such as an increased need to urinate during the night, anxiety, depression, and/or pain or discomfort due to chronic illness.

For the 6 million Americans who have Alzheimer’s disease (expected to reach 13 million by 2050), healthy sleep is even more elusive.

The Link Between Sleep and Dementia

While it’s a bit of a “chicken or the egg” question about whether sleep deprivation causes dementia or dementia causes sleep issues, experts agree on one thing: there is an unquestionable connection between sleep and brain function.

A 2021 study supported in part by the National Institute on Aging found that people in their 50s and 60s getting six or less hours of sleep per night were 30% more likely to be diagnosed with dementia. What’s more, the slow-wave activity that occurs during deep sleep decreases with age, causing deterioration in certain regions of the brain and a decline in long-term memory.

Additionally, dementia changes the body’s circadian rhythms, or sleep-wake cycle. Those with Alzheimer’s often have damaged cells and lower cellular activity in the suprachiasmatic nucleus of the brain and, thus, cannot follow a healthy 24-hour cycle of staying awake during the day and sleeping at night.

Interestingly, according to a study out of Boston University, those who slept more than 9 hours per night had double the risk of developing dementia as well as lower brain volume.

The Beta-Amyloid Factor

Perhaps most compelling in connecting sleep and dementia is research surrounding beta-amyloid, a protein in the brain associated with impaired cognitive function. When one sleeps a healthy number of hours per night, this protein – a metabolic waste product – is flushed out of the brain cells. Less sleep, however, can cause a buildup or clumping together of beta-amyloid, forming plaques that hinder communication between neurons in the brain.

PET scans have revealed that even one lost night of sleep caused an accumulation of beta-amyloid in the brain’s hippocampus and nearby regions.

Dementia and Common Sleep Problems

In addition to the myriad symptoms of dementia, there are some that are related specifically to sleep, such as:

• Obstructive sleep apnea (OSA) is a collapse of the airway at night, causing lapses in breathing. OSA occurs in 40% of Alzheimer’s patients and also increases one’s chances of developing dementia.
• Restless leg syndrome (RLS) is also common in those with dementia, particularly the Lewy body variation. RLS is marked by an irresistible impulse to move the legs at night.
• Periodic limb movement disorder (PLMD) is characterized byuncontrollable movement of the arms and legs; not surprisingly, many with this disorder also have restless leg syndrome.
• Depression is a mood disorder that is closely linked to insomnia, anxiety and other sleep complications. It is also very common in those with dementia and Alzheimer’s, increasing in severity as the disease progresses.
• Sundowners syndrome, explored here in this blog,cancause those affected to feel increased agitation, confusion and/or fear as evening approaches as well as exhibit behaviors such as wandering, yelling, even violent lashing out. This is a particularly common phenomenon in those with dementia.
• REM sleep behavior disorder involves the enactment of dreams in the form of shouting, jumping, grabbing, wandering from home, and otherconcerningbehaviors.

Preventing Sleep-Related Dementia or Improving Sleep for Those Affected

While there is no cure yet for Alzheimer’s or other forms of dementia, there are several practices that can either stave off the development of sleep-related dementia or improve precious shuteye for those with memory disorders. The benefits of good sleep hygiene are numerous and all-encompassing. Here are some ways to establish a healthy sleep routine:

• Set regular wake and sleep times. Adhering to regular, predictable sleep and wake times helps synchronize circadian rhythms and increase duration and quality of sleep at night.
• Get fresh air and regular exercise. While physical activity should be avoided close to bedtime, some amount of regular exercise, however light, during the day promotes more restful sleep. As often as possible, try to get outside in the fresh air.
• Limit napping. Napping during the day inhibits sleep at night. While no daytime snoozing is best, try to limit naps to only one for less than 30 minutes. If possible, engage in activity that stimulates the body and mind if daytime sleepiness comes on.
• Avoid blue light. Refrain from using electronic devices with sleep-inhibiting blue light at bedtime. Such light tells the brain it’s daytime, confusing the sleep-wake cycle and sabotaging slumber. However, reading at night (nothing too scary or adventurous!) from a book or e-reader without blue light or listening to soothing music or a calming app may invite sleep.
• Get adequate light exposure during the day. In addition to providing essential Vitamin D, natural light also regulates the sleep-wake cycle, improving sleep at night. As certain climates and times of year prohibit natural sunlight, light therapy may be a worthwhile alternative.
• Create a sleep-friendly bedroom environment. The boudoir is no place for stimulating television, electronics, conversations, etc. A restful bedroom is a calm, comfortable setting with quiet and relative darkness. Those with dementia might benefit from familiar objects within sight or reach and comforting nightlights.
• Avoid stimulants and alcohol. Caffeine, nicotine, alcohol and even some medications can severely inhibit sleep if taken too close to bedtime.
• Control pain. If chronic pain or a medical condition is the primary cause for sleeplessness, consult your doctor or a qualified medical professional to treat sleep-hindering physical or emotional discomfort (anxiety and depression significantly affect sleep).
• Add white noise. For some, a fan or white noise machine to mask outside sounds or “still the silence” is a welcome bedtime addition that encourages sleep.
• Follow a doctor’s medication regimen. Sometimes medication is required to induce sleep; however, it must be prescribed and managed by a qualified medical or sleep specialist. For patients with dementia for whom certain medications may exacerbate confusion or cognitive impairment, a doctor’s supervision is paramount.

For many people with dementia, establishing healthy sleep habits without the help of a caregiver or supportive senior community is not possible. Barclay Friends is here to help you navigate continuing care for your loved one, including person-centered memory care.