Why some brains refuse to switch off at night, researchers explain

From business-standard.com

Scientists have found that disrupted circadian rhythms may keep the brain alert at night, preventing the mental disengagement needed to fall and stay asleep

Your body may be ready for sleep, but your mind just refuses to wind down. For millions of people living with insomnia, this phenomenon occurs every night.

 

According to new research, the solution to this phenomenon may lie in the body’s internal clock. In a study titled Cognitive-affective disengagement: 24h rhythm in insomniacs versus healthy good sleepers, published in the journal Sleep Medicine, scientists have found that in people suffering from chronic insomnia, the mental clock, or the day-night rhythm of mental activities, is delayed and weaker in comparison to healthy individuals. This delays the process of moving from a sharp mental state to a dull mental state, which enables the start of sleep.

According to scientists at the University of South Australia, this delayed mental clock may be the reason for the constant mental activity in people suffering from insomnia.

What did the study find about Insomnia and Circadian rhythms?

For the study, 16 older adults with sleep-maintenance insomnia and 16 healthy adults with good sleeping habits were monitored for 24 hours under a ‘constant routine’ condition, where the lights were dim, no naps were allowed, and food was controlled, among other conditions.

 

Every hour, the participants were asked to rate the content of their thoughts, including the tone, quality and controllability of the thoughts.

The researchers found that mental activity has a predictable daily pattern in good sleepers. Afternoon mental activity is more structured, goal-oriented and reality-based. But as night approaches, the mind gradually changes. Mental activity becomes image-based, dream-like, unstructured and unrelated to goal-oriented activity.

 

They found clear circadian rhythms in healthy sleepers, with peaks in mental engagement in the afternoon and troughs in the early morning.

 

The researchers found 24-hour rhythms in people with insomnia as well, but their rhythms were flatter and delayed.

 

Three major differences stood out:

• Delayed peaks: Their cognitive peaks were delayed by about 6.5 hours. In effect, their brains were still running daytime-style thinking deep into the night.
• Reduced amplitude: The difference between their daytime alertness and night-time quietening was smaller. Scientists call this reduced “circadian amplitude”.
• Persistent sequential thinking: Insomniacs showed more “sequential” thinking, thoughts that move step-by-step in a logical chain, especially at night.

 

In other words, their brains failed to downshift.

Scientists say disrupted 24-hour brain rhythms may prevent the mind from switching off at night. (Photo: AdobeStock)

Is Insomnia just anxiety, or is there a brain link?

According to the study, anxiety levels were higher in insomniacs. Anxiety has been known to produce sequential thinking. However, the researchers do not consider anxiety to be the main reason for insomnia.

 

The study shows that it is possible that insomnia and anxiety have similar underlying causes in the brain. This is the hyperactivity of the prefrontal regions of the brain. The mind may not be willing to give up control.

What does cognitive hyperarousal mean in Insomnia?

Many people with insomnia describe a “racing mind”. Scientists refer to this as cognitive hyperarousal, a state in which the brain remains alert and engaged when it should be disengaging.

However, the hyperarousal may not just be psychological. It may be driven by a misaligned internal clock that keeps cognitive systems active too late into the night.

 

Sleep, as the authors note, is not merely closing your eyes; it requires the brain to disengage from goal-directed thought.

Can strengthening circadian rhythms help treat insomnia?

According to the researchers, if insomnia involves weakened or delayed circadian signals, then therapies aimed at strengthening daily rhythms could help. The researchers highlight interventions such as:

• Timed bright light exposure
• Structured daily routines
• Activity scheduling
• Mindfulness-based therapies to reduce sequential thinking

Mindfulness, in particular, may interrupt linear, chain-like thinking and encourage a more non-judgmental mental state, closer to the cognitive drift that precedes sleep.

If confirmed in larger studies, treatment could become more personalised to realign the brain clock of people suffering from insomnia.

https://www.business-standard.com/health/why-some-brains-refuse-to-switch-off-at-night-insomnia-study-126030300334_1.html

Why does your sleep change as you get older?

From irishnews.com

Many people have problems dropping off as they age, but disrupted nights shouldn’t be inevitable – here, experts suggest solutions that may help

There are many disadvantages to getting older – and one of them is poor sleep.

The British Geriatrics Society says approximately 40% of people aged 65 and over experience insomnia regularly, with up to 75% suffering from some form of sleep disturbance.

But in the approach to World Sleep Day (March 13), the good news is that although there are many reasons why sleep may deteriorate as you age, it doesn’t have to be that way.

“Fundamentally, your sleep doesn’t have to change in your 60s or 70s, but circumstances tend to create a lot more vulnerability around that ageing point,” says Professor Jason Ellis, director of the Northumbria Centre for Sleep Research at Northumbria University.

“A lot of the challenge  we have for older adults is they’re being taught this is normal – ‘Oh, it’s normal that you shouldn’t sleep well, just as it’s normal you should have aches and pains’. That’s not true. The vulnerability is there, but it’s not a fait accompli. It doesn’t mean that every older adult shouldn’t have good sleep.”

And Lisa Artis, deputy CEO of The Sleep Charity, adds: “It’s important to stress that poor sleep is not an inevitable part of ageing. While sleep patterns change, persistent sleep difficulties shouldn’t simply be accepted as ‘just getting older.’”

Increasing vulnerabilities

Both experts agree that certain vulnerabilities make older people more susceptible to sleep problems, and Ellis explains: “Once we hit our 60s, we’ve got a lot of things that increase vulnerability – illnesses, medications, multiple losses, those things can create more vulnerability to sleep problems.

“Similarly, we tend to put on a bit of weight, and that increases vulnerability to breathing problems at night. And menopause is not great for sleep at all, because you’re losing oestrogen and progesterone, and they help keep women’s sleep systems in terms of breathing at night quite open.”

Decreased melatonin

Ellis says melatonin, the hormone that helps regulate your sleep-wake cycle, decreases after puberty.

“That’s actually the beginning of the time our sleep system starts to degenerate,” he says. “So year-on-year, we start producing less melatonin naturally, and we start changing the architecture of our sleep.”

This means we start to lose some of the deep, slow-wave sleep needed for physical functioning from the age of about 25, he explains. “So by the time somebody’s reached their 60s, they’re a lot less structured with their internal sleep mechanisms than they were in their 20s. There’s a gradual decline.”

And Artis says:  “Sleep naturally changes as we age – particularly from our 50s onwards. While older adults still need around seven to nine hours of sleep per night, the structure and quality can shift quite noticeably.”

                                                             How to protect the quality of your sleep as you age (Alamy Stock Photo)

Shift in circadian rhythm

Several biological and lifestyle factors contribute to changes in the internal body clock of older people, says Artis. Hormonal shifts, including the reduced melatonin, play a role, she explains, and ageing is also associated with changes in brain function that affect sleep regulation

“Older adults often feel sleepy earlier in the evening and wake earlier in the morning,” she says. “This is sometimes referred to as a ‘phase advance’ in sleep timing.”

More easily disturbed

The decrease in deep, slow-wave sleep in older people means it’s easier for their lighter sleep to be disturbed, explains Artis.

“As we get older, we tend to spend less time in deep, restorative sleep and more time in lighter sleep stages,” she says. “This means we’re more easily disturbed by noise, light or physical discomfort, and many people also find they wake more frequently during the night and may struggle to get back to sleep.”

Lifestyle changes after retirement

(Alamy Stock Photo)

The rhythm of life tends to be a lot more structured for working people than retirees, Ellis points out. People who work will often have fairly regular times when they get up, eat, exercise, socialise, etc, whereas in retirement there’s less need for such structure, and this can affect sleep.

“Losing those patterns can make the system more vulnerable to being more flexible about getting bouts of sleep here and there, rather than in one big chunk,” he says.

And Artis adds: “Retired people may nap more during the day, be less physically active or spend less time exposed to natural daylight – all of which can influence sleep quality.”

Erratic sleep may not be good

Older people may think that as long as they get the right amount of sleep over a 24-hour period, it doesn’t matter when they get it. However, Ellis warns: “We’re starting to see research suggesting that keeping the same timing in sleep is actually as important, if not more important, than how much sleep we’re getting.

“We start to look at the regularity of sleep, as opposed to how much of it, if somebody is erratic. But unfortunately, most of the research has been done on younger adults or adolescents in this area, so we don’t fully understand yet whether the same thing applies with older adults and the regularity of their sleep.”

How is erratic sleep affecting you?

It’s natural for us to worry if our sleep has changed and/or we don’t think we’re getting enough of it. But Ellis stresses: “The first thing is to determine whether it’s causing you a problem. How do you feel in the daytime – is your sleep affecting your performance and what you need to achieve?

“If it is, then this is something you should be talking to your GP about.”

Ellis says these days a GP won’t automatically prescribe sleeping pills for a sleep problem – for insomnia, for example, he says cognitive behavioural therapy (CBT), which works on dysfunctional beliefs, attitudes and habits that may affect sleep, may be recommended.

And if someone’s sleep is being disturbed because of sleep apnoea (when breathing stops and starts while sleeping), continuous positive airway pressure (CPAP), which opens the airway at night, may be suggested, he says.

“There are lots of therapies out there, and they’re not all reliant on medication,” stresses Ellis. “It’s working out what the problem might be, and then tailoring that to the solution to try to maintain a better sleep health framework.”

And Artis points out: “While it’s common for sleep to feel lighter or more fragmented as we age, ongoing sleep difficulties shouldn’t be dismissed as simply part of getting older.

“Small adjustments to routine, light exposure and bedroom environment can make a significant difference. And importantly, support is available – good sleep remains vital for physical health, cognitive function and emotional wellbeing at every stage of life.”

https://www.irishnews.com/life/why-does-your-sleep-change-as-you-get-older-6PCVUUCVSJJHNMQ43SBZPCNH6A/

Is 7 Hours of Sleep Enough?

From healthcentral.com

Too much—or too little—shuteye can lead to serious health problems. Here’s what the experts say about how much sleep adults really need 

When it comes to how many hours of shuteye you get on average, the common recommendation for most adults is to clock at least seven hours each night, and that’s a solid general guideline, says Alex Dimitriu, M.D., a sleep medicine specialist and the founder of Menlo Park Psychiatry & Sleep Medicine in California.

However, it’s helpful to keep in mind that sleep duration can fluctuate based on things like age, lifestyle, illness recovery, pregnancy, or even existing underlying health conditions that you may, or you may not be, aware of.

“For most adults, seven hours is the minimum needed to function well, with nine hours as the maximum, but individual needs can vary quite a bit,” Dr. Dimitriu notes.

The most important thing to understand about sleep? Getting too few—or too many—ZZZs is strongly correlated with potential health issues, he notes. Frequently falling outside the seven-to-nine hour per night sleep window may not always be the cause of those problems, he adds, but can sometimes be an indication that something deeper may be going on. With that in mind, are you getting enough shuteye? Too much? We unpack what the science shows so you can rest easy.

Sleeping Seven to Nine Hours Is the Sweet Spot

Although your individual sleep needs may vary within the seven-to-nine hour timeframe recommendation, there is ample evidence that regularly sleeping less, and also sleeping more, may be detrimental to health, agrees Evin Jerkins, D.O., a sleep medicine specialist at Fairfield Healthcare in Lancaster, OH.

“At this point, there’s a large amount of evidence suggesting sleeping less than six hours a night leads to a higher risk of hypertension, type 2 diabetes [T2D], obesity, coronary artery disease, and stroke,” he explains. Regular shortened sleep can also have effects on mental health and is linked to higher risk of anxiety, depression, and problems with emotional regulation, according to 2025 research published in the American Journal of Lifestyle Medicine.

Consistently sleeping too little health risks because the body and brain go through crucial restorative processes during sleep phases, says Dr. Jerkins. For example, you'll experience higher levels of cortisol—the “fight or flight” hormone—without enough sleep, which can then elevate blood pressure and inflammation in the body. Sleep also plays a key role in brain health, since it's the time when new pathways are formed, waste is cleared, and memory is consolidated.

Regularly oversleeping, on the other hand, which is defined as getting more than nine hours of sleep per night, is also potentially harmful to your health. Took much shuteye is associated with the very same risks—including heart disease and T2D—that is seen with sleeping too little, per Johns Hopkins Medicine.

But, if not enough sleep is wreaking havoc on your body and mental health, wouldn’t “catching up” on your ZZZs be a good thing? Not so fast. Sleeping nine-plus hours per night can disrupt the body’s natural circadian rhythm, which in turn has been linked to higher inflammation and changes to metabolism. Also known as your body clock, your circadian rhythm regulates numerous physiological processes, including your immune response and brain function, according to research in Frontiers in Cellular and Infection Microbiology. When inflammation rises due to this rhythm being thrown off, it can affect how well your immune system works, proper hormone regulation, and your ability to stay alert all day.

“While there is no magic number for sleep … seven to eight hours is the sweet spot for most healthy adults,” Dr. Jerkins confirms. “If you’re consistently getting too few or too many hours of sleep, that doesn’t necessarily mean you have a health issue that leads to sleep disruption or insomnia. But it's important to see your doctor to rule out a serious condition that may be affecting your sleep,” he advises.

Sleep Needs Can Change With Age

A major variable in sleep needs is age, says Dr. Dimitriu. Older adults need the same amount of sleep as younger people but often get less total sleep at night, he explains. This can be due to several factors, such as:

• Chronic illness. Numerous age-related diseases can cause both sleep disruptions or chronic fatigue, including arthritis, osteoporosis, and Alzheimer's disease.

• Menopause-related hormone changes. Night sweats from oestrogen loss can disrupt sleep.

• Side effects of certain medications. Older adults tend to be on a higher number of medications, and some common drugs can disrupt sleep including beta-blockers, antidepressants, inhaled asthma drugs, and diuretics that are used to manage blood pressure.

• Sleep disorders. Insomnia, sleep apnoea, and movement issues such as restless legs syndrome are more common as people age, per the National Institute of Aging.

Yet, while many things can disturb sleep as we grow older, clocking those seven to nine hours may be more important than ever. According to the National Institute on Aging, lack of quality sleep can lead to problems with memory, increased risk of falls or accidents, and more stress overall. Research suggests that not sleeping enough, even in middle age, can raise risk of developing dementia later in life.

Because of the importance of quality sleep, it may be necessary to augment night-time sleep with daytime napping, advises Dr. Jerkins, even if that means getting seven to nine hours of sleep within a 24-hour period if you are 65 or older, rather than aiming for that amount in one block overnight. Just be sure to stay within that seven-to-nine hour range, rather than getting too much sleep due to long naps. Also, nap in the late morning rather than late afternoon, so you don't sabotage your bedtime later, he suggests.

Some People Just Need More Sleep

There are some situations where more sleep is necessary, says Dr. Dimitriu. However, those tend to be short-term needs that affect people who are recovering from, or living with, some type of injury or condition. They include:

• Athletes. People who physically push their bodies may need longer recovery time from a major training session or race.

• Chronic community. People with chronic disorders, including autoimmune diseases and cancer, may require more sleep each night.

• People who are healing. Bouncing back from illness or injury may up your need for additional ZZZs.

• Pregnant women. Research suggests that pregnancy is also a time for more sleep, but paradoxically, pregnancy can be rife with significant sleep disturbances due to nausea, heartburn, and back pain. Much like older adults, napping can help add to the total amount of hours for sleep in a 24-hour period.

• Those with mental health conditions. This may include people with depression or bipolar disorder, who need more sleep to improve cognitive function, Dr. Dimitriu says.

• Signs You're Not Getting Enough Sleep

If you’re regularly getting a minimum of seven hours of sleep, and you wake up feeling rested, especially without using an alarm, and you have consistent energy throughout the day, then it's likely you’re hitting your target when it comes to sleep amount, says Dr. Jerkins. Signs that you may need to increase your amount can include:

• Daytime sleepiness

• Difficulty focusing or paying attention

• Emotional regulation problems, such as irritability or anxiety

• Falling asleep very quickly

• Food cravings, especially for carb-filled snacks

• Hard time waking up in the morning

• Increased clumsiness

• Memory issues, including forgetfulness

• More prone to catching common infections, such as cold or flu

• Needing an energy boost like caffeine or sugar to get through the day

• Slower reaction time

“Keep in mind that duration of sleep alone is not the only factor here,” Dr. Jerkins adds. “Quality sleep is also crucial. A good first step for both of those is going to bed and waking up at the same time on weekdays and weekends, to establish a consistent sleep schedule.”

https://www.healthcentral.com/sleep/is-seven-hours-of-sleep-enough

"My sleep-tracking earbuds discovered how this one thing in my night-time routine ruined my sleep"

From tomsguide.com

By Frances Daniels

My sleep tracker helped me realize why I found it so hard to fall asleep one night 

It's difficult to know how long it takes you to fall asleep. Unless, of course, you have a sleep tracker.

Yes, there have been low-tech ways to measure sleep onset latency, such as the spoon test (one of TikTok's many sleep trends) or sleep journaling, but these are harder to perform and much less accurate.

Sleep trackers, on the other hand, do the work for you and provide precise results, as I recently found out when testing the Fitnexa SomniPods 3, now $179.99 down from $189.99 at Fitnexa.

I wanted to see if the SomniPods could join the ranks of the best sleep headphones but they ended up discovering something about me.

Unsurprisingly, the sleep-tracking earbuds showed that the time it takes me to fall asleep is between five and 20 minutes —a common sleep latency for most adults — expect on one night.

During that night, my sleep tracker not only noted I was having trouble falling asleep, it alerted me, making me retrace my steps to find out what independent variable was causing this short-term sleep onset insomnia.

Here's what was causing my trouble sleeping — and why I won't do it again.

What my sleep tracker helped me realize about my insomnia

I had been using the Fitnexa SomniPods 3 for over a week and a half when it helped me spot where my sleep hygiene was going wrong.

From the first night I used them, the SomniPod's sleep data showed me that, while my sleep was far from perfect (I'm not getting anywhere near enough REM sleep for a start), my sleep latency was on track for a healthy adult.

I use sleep-tracking earbuds to measure how long it usually takes me to fall asleep. (Image credit: Future)

However, one night, it wasn't...

I always I assume that it's taking forever to fall asleep and then I wake up and the data shows it didn't take taking long at all. But one night, the Fitnexa app proved that this time, it wasn't all in my head.

(Image credit: Future)

"I noticed you're still awake," messaged Lana, an AI-powered personal wellness assistant within the Fitnexa app, over 30 minutes after going to bed. "Are you having trouble falling asleep?"

As my self-described 'sleep guardian' had never said this before, it caused me to retrace my evening routine and re-evaluate a seemingly innocuous activity: watching a true crime documentary.

I'm not a stranger to true crime but usually I watch or listen to it during the day. That means by the time I go to bed, enough time (and comedies) have passed to cleanse my brain of the creepiness.

However, watching it at night meant the disturbing content still lingered in my head (it also didn't help that both my roommates were out of town).

Why unsettling content before bed can cause sleep issues

Why did I know that watching a true crime documentary was the root of my insomnia? Well, for a start, it's was the only thing that I'd added to my nighttime routine.

And second, disturbing or unsettling content such as true crime documentaries, horror movies, violent shows, or even a fear-mongering news article, are known to be sleep disruptors.

According to Hannah Shore, the Head of Sleep Science at Mattress Online, this disruption dates back to our earliest ancestors, who could sleep when they knew they were safe from prehistoric predators.

(Image credit: Getty)

"Now, we still only sleep when we feel safe, but instead of a sabre-toothed tiger hunting us, different stressors keep us awake," Shore tells me. "This could include some of the content we consume directly before bed."

"When we consume content that is distressing just before we go to bed, it can leave us feeling a little unsafe," she continues. "This can prompt the fight or flight response system, meaning the body is producing wake-promoting hormones, such as adrenaline and cortisol, which prevent you from falling asleep easily and lead to increased warning throughout the night."

What to do if you can't sleep after reading or watching unsettling content

(Image credit: Getty Images)

If you've already watched or read something disturbing, either advertently (watching a scary movie) or inadvertently (receiving a nasty text from someone) and can't fall asleep, Shore says there are way to get re-settled and start "producing sleep-related hormones, like melatonin, which will help us drift off to sleep more easily."

"Try watching or reading something more lighthearted for 30 mins before you try to sleep," she suggests.

Who knew re-watching an episode of Friends you've seen 100 times could be such a sleep fix?

How can you avoid unsettling content before bed?

Revisit an episode of your favourite sitcom instead of doom scrolling (Image credit: Shutterstock)

While it's easy to avoid horror movies (just don't watch 'em) before bed, it isn't always easy to steer clear of distressing content in this digital age of doomscrolling.

"You never know what will appear next on your social media feed, so I recommend trying to stay off that," Shore warns.

In terms of what you should be doing to get settled before bed, Shore advises relaxing activities, such as breathing exercises, mindfulness, and rereading or re-watching your favourites.

"By re-watching or rereading something you know, you are more likely to fall asleep more easily than when you are watching or reading something new," says Shore. "It can provide you a little comfort knowing that there are no surprises."

https://www.tomsguide.com/wellness/sleep/my-sleep-tracking-earbuds-discovered-how-this-one-thing-in-my-nighttime-routine-ruined-my-sleep-heres-why-i-wont-do-it-again