There is nothing quite like the loneliness of the insomniac, awake while the rest of the world slumbers. You crave nothing more than a few snatched hours of sleep.
Your limbs ache with fatigue and you feel irritable. You cannot think clearly and your vision is blurred.
To the outside world, there is nothing keeping you awake, though. It is your own brain. You are your own torturer.
Of all the sleep problems seen in clinics, insomnia is the most common by a significant margin. Roughly one-third of adults report poor sleep in any one year, and about one in ten has chronic insomnia, resulting in poor sleep coupled with daytime consequences, such as fatigue, irritability, difficulty concentrating and lack of motivation.
What many people may not realise is that there are different types of insomnia, and not everyone with insomnia is deprived of sleep.
Fact: Insomnia is complex. It is not only a medical condition in itself, it can also be a symptom of other medical conditions, such as an overactive thyroid gland
For some, sleep may be disrupted several times a night, yet when we look at their sleep under laboratory conditions, the total amount they’re getting is still within the normal range.
In other words, while they might think they’re getting only a couple of hours of ‘proper’ sleep, their brain activity suggests otherwise.
Even those people who have a reduced total sleep duration can sometimes still have normal amounts of deep sleep — the stage most important for physical restoration and refreshment.
For others, however, there is clear evidence of very curtailed sleep, with sometimes just a few snatched hours each night.
Depending on the type, insomnia can have long-term health implications — and may be more difficult (or easier) to treat.
WHICH INSOMNIA TYPE DO YOU HAVE?
Insomnia is complex. It is not only a medical condition in itself, it can also be a symptom of other medical conditions, such as an overactive thyroid gland.
Likewise, there are psychological factors in the mix. Roughly half of patients with chronic insomnia have underlying psychiatric disorders, especially anxiety.
There are also genetic factors at play. It often runs in families, and studies of twins have suggested that 57 per cent of insomnia cases can be explained by genes.
Did you know? The health risks of sleep deprivation are well documented: it raises the risk of premature death, weight gain, high blood pressure, type 2 diabetes
Using scans and monitoring brainwaves, we can see the different types of insomnia are linked to the brain being more active than normal during sleep. However, there are other key physical differences between the types — so much so that some experts have suggested they are fundamentally different conditions.
In people who sleep for only a few hours a night — which we call short sleep duration insomnia — we can see clear biological markers of stress, or ‘hyperarousal’, as they drop off: that jangling of nerves, the racing heart, and being on full alert.
This leads to levels of the stress hormones cortisol, adrenaline and noradrenaline that are higher than normal, and in short sleep duration insomniacs, we see increased levels of the breakdown products of these hormones in their urine.
This category of insomniacs also has a faster nocturnal heart rate and increased oxygen consumption, implying a higher metabolic rate.
Interestingly, people with this type of insomnia are less likely to become obese than people who sleep normally, despite the obesity risk normally associated with sleep deprivation. Their pupils are also bigger compared with normal sleepers — a measure of the heightened activity of the sympathetic nervous system, which controls the ‘fright-fight-flight’ response — our physical reaction to stress.
Importantly, these changes are not seen in those people with insomnia who are actually getting a reasonable total amount of sleep.
GOOD NEWS FOR THE BLEARY-EYED
The health risks of sleep deprivation are well documented: it raises the risk of premature death, weight gain, high blood pressure, type 2 diabetes . . . the list goes on. So it is natural for people with insomnia to worry about these issues.
Surely decades of poor sleep would give rise to the same damaging consequences on health as we see in people who simply don’t let themselves sleep enough?
Not necessarily. And here, the type of insomnia is important.
In people who sleep for only a few hours a night — which we call short sleep duration insomnia — we can see clear biological markers of stress, or ‘hyperarousal’, as they drop off: that jangling of nerves, the racing heart, and being on full alert
Despite both types having increased brain activity, many of the health problems related to insomnia seem limited to those with short sleep duration insomnia. For instance, studies of cognitive performance in people who say they have insomnia do not show major differences when compared to normal sleepers.
But when you separate those with normal amounts of sleep, even poor-quality and broken sleep, from those with objectively measured short sleep, it is the insomniacs with short sleep duration who have significant cognitive problems.
Similarly, when the risks of conditions such as high blood pressure and diabetes are analysed in people with insomnia, those who have been confirmed as sleeping for only a very short period each night have higher rates of risk of these conditions, while those sleeping six hours or more appear to have no increased risk.
Although they will still feel like they’re not sleeping well, from a physical perspective, this group of insomniacs shares more with people who have normal sleep. There’s also evidence this type of insomnia responds better to treatment.
IS GETTING LESS SLEEP THE ANSWER?
Claire was typical of many insomniac patients I see. When she walked into my consulting room, there was nothing to suggest anything was wrong — in her early 50s, she was slim and well dressed.
However, for five years, she had been plagued by debilitating insomnia. She told me her sleep initially worsened as she approached the menopause — as it does for a lot of women — but she could still function during the day. She believed the precipitating cause of her insomnia was the pressure of a new job.
What happens to sleep rhythms as we age?
As we pass through life, our sleep changes both in quantity and quality.
A newborn will sleep for two-thirds of the day, but, by adulthood, we tend to sleep between six-and-a-half and eight-and-a-half hours a night.
Nor is sleep a static state — it has multiple stages. As we drift off, we enter stage 1 sleep, also known as drowsiness; then stage 2, light sleep, when brain activity slows further.
Stage 3 is deep sleep: within 30 minutes or so of drifting off, brainwaves slow considerably, but increase in size. The final stage, which we enter after around 60 to 75 minutes, is rapid eye movement (REM) sleep, so-called as our eyes rapidly dart back and forth.
During REM sleep, the brainwaves look to be highly active — a little like being awake — and it is then that we most obviously dream.
As adults, we move through these various stages usually four or five times a night, with the majority of deep sleep in the first half of the night and the majority of REM sleep in the second. As newborns, we spend around half of our slumber in REM sleep, while in adults it’s 15 to 25 per cent, gradually falling as we approach old age.
The proportion of deep sleep changes, too, being roughly 15 to 25 per cent in adulthood, but dropping a little in the elderly, usually replaced by Stage 1 and 2 sleep. As we get older, the number of brief awakenings throughout the night also increases.
Deep sleep is thought to be when our brains do more of their housekeeping in clearing out waste substances and toxins.
‘I’d gone back to work after 15 years at home with the children,’ she told me. ‘It was partly me being 50 and wanting to prove myself in the workplace.
‘Soon, I stopped sleeping. I would go to bed, but as I walked upstairs I would get panicky. My heart would start beating fast. I could feel the adrenaline coursing through me. I’d lie in bed for a couple of hours, then I’d give up and make myself a cup of herbal tea, walk round the kitchen, keeping the lights low.
‘Then I’d try again. Towards the early hours I’d get some kind of very light, dreamlike sleep, but I’d wake up feeling wrecked.’
And so began the downward spiral. Her lack of sleep made it more of a struggle to perform to her own expectations at work, raising her anxiety levels further and making sleep more elusive.
It also took its toll on her relationship. ‘Sometimes I’d wake up my husband, crying and semi-hysterical — I hate to admit that,’ she said. ‘He would be very sweet and he’d try to calm me down.’
When I saw Claire, she’d already been diagnosed with anxiety and depression. Finding the right antidepressant helped her a lot, but her sleep was still terrible.
She had been trialled on several medications and had also tried ‘acceptance and commitment’ therapy, where people are taught to accept or embrace their insomnia to reduce the stress associated with their lack of sleep — the theory being that this can make it easier to sleep. But so far, nothing had worked long term.
Historically, treatment of insomnia has focused on medication. Benzodiazepines hit the market in the Sixties and rapidly became the staple.
But, over the past few decades, the dangers of benzodiazepines and related drugs have become apparent: the risk of traffic accidents, falls and fractures, withdrawal effects and dependence, with larger doses needed to get the same effect on sleep.
Most alarmingly, there is growing evidence that points to benzodiazepines increasing the risk of dementia.
Accordingly, there has been a massive shift towards non-drug-based treatments. The most used of these is cognitive behavioural therapy for insomnia, or CBTi.
Essentially, this aims to re-programme the brains of people with insomnia to once again establish the bed as a sanctuary, rather than a torture chamber.
Genetic cause and effect? It often runs in families, and studies of twins have suggested that 57 per cent of insomnia cases can be explained by genes.
It involves a rigid regimen to avoid you lying in bed at night for prolonged periods while awake, forcing you to leave the bedroom after 20 minutes of struggling to get to sleep.
It also involves limiting the time allowed in bed to five or so hours for a couple of weeks. This may sound counterintuitive, but what many people with insomnia do is compensate for their poor sleep by spending more time in bed. This increases the amount of time they are in bed and not asleep, thus strengthening the negative conditioned response they have to their bed.
Limiting the time allowed there instead builds the brain’s drive to sleep. Eventually, the sleep deprivation overrides the anxiety they feel around bedtime and sleep follows.
While medications can have a place, CBTi should be the default first-line treatment for almost everyone with insomnia. Your GP should be able to refer you to a local service, or online CBTi, via the NHS or privately.
THE 24-HOUR RETRAINING ‘CURE’
At its most extreme, sleep deprivation as a treatment for insomnia has been developed into an experimental technique called intensive sleep retraining.
The patient is asked to stay in bed for no more than five hours the night before they come into the sleep laboratory. Starting at 10.30pm, for the following 24 hours, every 30 minutes, the patient is allowed to try to sleep.
If, after 20 minutes, they do not fall asleep, they are asked to get up. But if they do fall asleep, after three minutes they are woken. By the end of the 24-hour period, they have had a total of 48 opportunities to fall asleep.
In theory, by the end of the protocol, they are so sleep-deprived that they fall asleep as soon as they are allowed.
Results from trials have been impressive. This short, sharp shock rapidly reconditions the response to getting into bed, and results in quick improvements.
Volunteers’ sleep diaries from the initial clinical trials showed they were getting to sleep between 24 and 30 minutes quicker and getting up to an hour’s more sleep. Daytime fatigue was ‘significantly reduced’.
For Claire, we decided to go down the CBTi route. Patients can see a benefit within weeks.
When I spoke to her some nine months after we first met, she told me she was ‘fabulous’. Her anxiety had lessened, and she was sleeping regularly. She was still on a low-dose antidepressant but reducing this gradually.
‘I had felt like my body and my brain were shutting down,’ she told me. ‘And suddenly, with sleep, it’s all opening up again.’
Dr Guy Leschziner is a consultant neurologist and sleep physician at Guy’s Hospital. Adapted from The Nocturnal Brain: Tales Of Nightmares And Neuroscience by Dr Guy Leschziner, Simon & Schuster, £16.99. To order a copy for £13.59, visit mailshop.co.uk/books or call 0844 571 0640. P&P free on orders over £15. Spend £30 on books and get FREE premium delivery. Offer valid until March 19, 2019.
BUT YOU MAY BE GETTING MORE SLEEP THAN YOU THINK…
We live in an age where everything needs to be measured, be it how many steps we take, how many Instagram followers we have — and, of course, how much sleep we get.
But I do wonder if this obsession with number of hours is helpful. If you feel tired and unrefreshed in the day, you probably are not getting enough sleep — but you don’t need a sleep tracker to tell you this.
And there is a further issue. If you are already worried about your sleep, then constantly tracking it can intensify your obsession, and thus make any sleep problem worse.
This phenomenon now has a term — ‘orthosomnia’ — where people are diagnosing themselves with sleep disorders based on their sleep tracker’s output.
On the other hand, sometimes such devices can help by proving that someone is getting more sleep than they think — although it does depend on the measurement being accurate, and this is not always the case (five different trackers are likely to give you five different verdicts).
This is a problem known as ‘sleep state misperception’ or ‘paradoxical insomnia’.
It is rare that I bring patients with insomnia into the sleep laboratory. Someone who does not sleep very well at home will definitely struggle to sleep covered in electrodes, in a strange bed.
Occasionally, though, I will admit patients for a night, and afterwards, when I ask how they slept, it is incredibly common to hear, ‘Terribly’, and that they only slept for an hour or two.
Yet their sleep study shows a very decent night’s sleep — seven or more hours, with plenty of deep sleep, which is the most restorative kind.
Clearly, something about the way the person experiences sleep is different. Perhaps it is the quality of sleep that is going wrong for these people.
Quality is something we cannot yet gauge with our technique of measuring sleep — the polysomnogram. This measures brain activity, breathing and heart rates, oxygen levels in the blood, and eye and limb movements. Or maybe it is as simple as the brain filling in time between the brief awakenings that are a feature of normal sleep. So the patient perceives wakefulness rather than the deep sleep that their brain activity suggests it is.
Either way, it illustrates that there are many factors — biological, psychological, behavioural, environmental — that all influence sleep quality as well as sleep quantity.
And for most people, sleep is a subjective experience.
TEST TO CHECK YOUR SLEEP IS NORMAL
One of the most frequently asked questions I hear in my sleep clinic is: ‘How much sleep is enough?’
It’s a question I do not answer — at least not with a number of hours. Indeed, I cannot answer it in that way. The question is similar to ‘What is the normal height for a ten-year-old?’
If I look at my daughter’s class photo, the children range in height hugely, but all of them are normal. Likewise, there is a range of normal sleep requirements. It depends on your genes, and the quality of your sleep.
The right amount of sleep is the number of hours needed for you to wake up feeling refreshed, not sleepy during the day, but then ready for bed at a regular time, with no difficulty dropping off.
If you are waking up before your alarm, and not needing to catch up on sleep when you have the chance at the weekend, then you are getting the right number of hours’ sleep.