Experts have warned that cognitive decline could result in a change in sleeping habits
03:30, 29 Aug 2025Updated 07:15, 29 Aug 2025
Some of the lesser-known signs of dementia can appear during the night(Image: Getty)
Lesser-known early warning signs of a devastating condition affecting nearly one million Brits could become apparent at night. Sleep-related symptoms might be an early indication of dementia.
Dementia is a syndrome, or a group of symptoms, linked with progressive brain deterioration. Predominantly impacting individuals aged 65 and above, symptoms such as memory issues can be mistaken for normal ageing processes.
However, cognitive decline can also disrupt sleep patterns. The Alzheimer’s Society points out that those living with dementia may experience specific sleep disturbances.
As stated on the charity’s website: “A person with dementia experiences physical changes in their brain because of their condition.
Almost one million people in the UK are thought to be living with dementia(Image: Getty)
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 charity has highlighted that dementia patients may:
- Find it difficult to drift off to sleep
- Wake up repeatedly throughout the night
- Have reduced periods of deep sleep
- Sleep for briefer periods in total
Furthermore, they could rest more during daylight hours and struggle to sleep at night. “This process can start to happen even before a person has dementia, or if they have mild cognitive impairment (MCI),” the organisation continued.
Recent research, published in the journal Neurology, indicated that sleeping patterns could signal future dementia risk. The study found that people who feel progressively sleepier during the day and may take “excessive” naps are twice as likely to develop the condition.
Across five years, the 733 study participants were separated into three groups:
- 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)
After a five-year monitoring period, scientists established whether participants retained normal cognitive abilities, developed mild cognitive impairment, or advanced to dementia. The evaluation was based on thorough neuropsychological examinations, medical diagnoses, or placement in care homes.
“A person with dementia may have problems with sleeping at night, and may sleep more during the day,” the Alzheimer’s Society says(Image: getty)
Among the group of octogenarian women, 164 individuals (22.4 per cent) developed mild cognitive impairment whilst 93 (12.7 per cent) advanced to dementia. The results showed that women experiencing heightened drowsiness faced approximately double the dementia risk when compared to those maintaining steady sleep habits.
The research team stated: “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.”
Furthermore, separate research published in the Alzheimer’s and Dementia journal in 2016 showed that both excessive and insufficient sleep duration increased the risk of cognitive decline and dementia. In addition, a study from 2021 featured in the Nature Communications journal suggested that reduced sleep duration during middle age was linked with a higher risk of dementia.
The NHS lists the “common” early warning signs of dementia as:
- Memory loss
- Difficulty concentrating
- Struggling with familiar daily tasks, such as getting confused over the correct change when shopping
- Difficulty following a conversation or finding the right word
- Confusion about time and place
- Mood changes
If you or someone you know is showing symptoms of dementia, it is recommended to seek medical advice.