Certain sleeping habits could indicate cognitive decline before other warning signs

Some lesser-known early warning signs of a devastating condition that affects more than six million Americans could appear at night. Sleep-related symptoms could signal dementia before other indicators become apparent.

Dementia is a syndrome, or a collection of symptoms, associated with progressive brain deterioration. Predominantly affecting people aged 65 and above, manifestations such as memory difficulties are frequently confused with typical ageing processes.

However, sleep patterns may also be disrupted as a result of cognitive decline. The Alzheimer’s Society highlights that those living with dementia might encounter specific sleep disturbances.

According to the charity’s website: “A person with dementia experiences physical changes in their brain because of their condition.

“These changes can affect how much, and how well they sleep. A person with dementia may have problems with sleeping at night, and may sleep more during the day.

“They may find it difficult to get to sleep or they may wake up in the night. The person you care for may not feel well rested when they wake up.

“Over time, if these problems happen often, poor sleep may make the symptoms of dementia worse. You may find this difficult to cope with.”

The organisation added: “For a person with dementia, getting enough sleep can be a challenge. Sleeping well can be difficult for a person aged over 55, as the parts of the brain that control sleep may not work as well.

“An older person is likely to go to sleep earlier and may have difficulty sleeping through the night as much as they used to.”

The society has outlined that dementia patients may:

* Struggle to fall asleep

* Awaken multiple times during the night

* Experience less deep sleep

* Sleep for shorter durations overall

Additionally, they might sleep more during the day and find it challenging to sleep at night. “This process can start to happen even before a person has dementia, or if they have mild cognitive impairment (MCI),” added the charity.

A recent study, published in the journal Neurology, suggested that your sleeping habits could indicate your chances of developing dementia in the future. The research discovered that individuals who feel increasingly drowsy throughout the day and may take “excessive” naps are twice as likely to develop dementia.

Over a span of five years, the 733 participants of the study were divided into three categories:

* Stable sleep (SS) – stable or slightly improved sleep, demonstrated by 321 women (43.8 per cent)

* Declining nighttime sleep (DNS) – decreases in nighttime sleep quality and duration, moderate increases in napping, and worsening circadian rest-activity rhythms (RARs), demonstrated by 256 women (34.9 per cent)

* Increasing sleepiness (IS) – significant increases in both daytime and nighttime sleep duration and quality, as well as worsening circadian RARs, demonstrated by 156 women (21.3 per cent)

* Following a five-year period, researchers determined whether participants maintained normal cognitive function, developed mild cognitive impairment, or progressed to dementia.

This assessment relied on comprehensive neuropsychological testing, medical diagnosis, or admission to residential care facilities. Within the group of women in their 80s, 164 people (22.4 per cent) developed mild cognitive impairment while 93 (12.7 per cent) progressed to dementia.

The findings revealed that women experiencing increased drowsiness had roughly twice the dementia risk compared to those maintaining consistent sleep patterns. The study’s authors concluded: “Among community-dwelling women in their 80s, those with increasing 24-hour sleepiness over five years had doubled dementia risk during that time.

“Change in multidimensional 24-hour sleep-wake activity may serve as an early marker or risk factor for dementia in oldest old women.” Additionally, separate research published in the Alzheimer’s and Dementia journal in 2016 demonstrated that both excessive and insufficient sleep duration heightened the risk of cognitive decline and dementia.

Meanwhile, a 2021 study featured in Nature Communications journal indicated that reduced sleep duration during middle age correlated with elevated dementia risk.

The National Health Service (NHS) in the UK identifies the “common” early warning signs of dementia as:

* Memory loss

* Difficulty concentrating

* Finding it hard to carry out familiar daily tasks, such as getting confused over the correct change when shopping

* Struggling to follow a conversation or find the right word

* Being confused about time and place

* Mood changes

If you or someone you know is exhibiting symptoms of dementia, it is advisable to consult with a doctor.

Written by Fiona Callingham for The Mirror US ~ August 28, 2025