Dementia is an irreversible loss of brain function that affects memory, language, problem-solving, and other cognitive processes. There are different types of dementia, all of which tend to affect older adults. Dementia is marked by brain cells not functioning as they should and dying off more quickly than they do in people without dementia. There isn’t a known cure for dementia, but available treatments can slow its progression.
Sleep problems are common in individuals with dementia, and sleep loss may contribute to or exacerbate the severity of other dementia symptoms. Caregivers report disturbed sleep to be one of the most distressing dementia symptoms. Identifying and treating sleep issues is a critical part of dementia care as it alleviates stress for patients and caregivers and could potentially slow cognitive decline.
Circadian rhythm is a collection of physical and psychological processes that guide our sleep-wake cycle by responding to indicators in our environment. People with dementia experience fundamental changes in their circadian rhythm that work against getting quality sleep on a regular schedule.
The suprachiasmatic nucleus (SCN) is the part of the brain that serves as our internal clock and responds to cues, such as light, to indicate when we should be alert and when we should feel sleepy. Individuals who have Alzheimer’s disease—the most common type of dementia—often have damaged cells in the SCN and decreased cellular activity in this part of the brain. The result of this dysfunction is that patients are often unable to follow a 24-hour sleep-wake cycle and instead sleep excessively during the day and sleep much less at night.
Additionally, dementia is associated with changes in sleep structure. When we sleep, our bodies cycle through a series of sleep stages, from light sleep (stages 1 and 2), to deep sleep (stage 3 or slow-wave sleep), and then dream sleep (also called rapid eye movement or REM sleep). Slow-wave sleep and REM sleep are critical parts of how sleep works to restore the body and mind. People with dementia spend less time in slow-wave sleep and REM sleep and more time in the earlier stages of sleep. This reduction of deep sleep and REM sleep can worsen as dementia progresses.
Research has documented a number of sleep changes that occur in healthy aging adults. These include bedtimes and wake times shifting to an earlier hour, taking longer to fall asleep once in bed, experiencing fragmented sleep, sleeping fewer hours per night, and spending less time in slow-wave and REM sleep. Although these changes parallel some of the sleep challenges seen in people with dementia, the sleep pattern changes in dementia patients tend to be more dramatic and disruptive.
People with dementia are frequently affected by sleep disorders. The following sleep disorders are found most often in older adults, but they are seen at even higher rates in people with dementia.
“Sundowning” is a phenomenon in which individuals with dementia experience increased agitation later in the day and in the evening. The symptoms of sundowning include confusion, anxiety, wandering, and yelling. Sundowning can contribute to insomnia and other sleep problems when these behaviors continue into the night. Possible causes of sundowning include the circadian rhythm changes that occur in dementia, as well as fatigue, depression, and pain.
People with dementia may also talk, yell, or cry out at night if they cannot sleep. Some dementia patients have a tendency to wander away from their homes, which can be especially dangerous at night. In dementia patients with REM sleep behavior disorder, shouting, grabbing, jumping, and other behaviors are related to dream enactment during sleep.
Experts suggest that sleep and dementia may share a bidirectional relationship. This means that while sleep could affect dementia risk and symptoms, the presence or absence of dementia also affects sleep quality. For example, one of the first Alzheimer’s disease symptoms in the brain is the accumulation of a protein called amyloid-beta, which eventually forms clumps called amyloid plaques. Animal studies and a small study in people have shown sleep deprivation to increase the levels of amyloid-beta in the brain. At the same time, Alzheimer’s patients with amyloid plaques have been shown to have worse sleep quality than Alzheimer’s patients who do not have amyloid plaques.
Additionally, sleep is known to be critical for our cognitive functioning and memory formation. Observational studies have shown that sleep issues are associated with cognitive decline and dementia. However, these studies do not prove a cause-and-effect relationship. Although more research is needed to better understand sleep and dementia risk, there are many proven steps you can take to improve your sleep.
Sleep hygiene is the primary treatment for sleep concerns in people with dementia. Sleep hygiene is a collection of practices and environmental considerations that promote good sleep quality. The following sleep hygiene tips may help a person with dementia improve their sleep patterns:
Some of these sleep hygiene practices may be difficult for someone with dementia. For example, it may not be possible to control the bedroom noise level in a nursing home or assisted living facility. Consider adding a white noise machine to mask outside noise. A person with dementia may also have a difficult time maintaining a regular bedtime due to napping or varied daily activities, but keeping wake time consistent can still help to stabilize the circadian rhythm. A physician or sleep specialist is in a good position to provide individualized sleep hygiene recommendations for a specific situation.
Medications are seen as a last-resort option for people with dementia. The risks of sleep aids include increased confusion, sedation, and risk for falls or injury. Be sure to speak with a doctor before giving a sleep aid to a person with dementia.