Is sleep deprivation and insomnia different? What actually happens in the human brain when we’re sleep deprived. What changes occur in the body when we have a night of poor sleep?
First of all, think it’s really important to clearly differentiate between what we mean by insomnia and what we mean by sleep deprivation, because quite commonly they actually get mixed up in places like in the media, and even in scientific articles some of the time. That leads to lot of confusion and to conclusions about one that might not be to do with that. Sleep deprivation is what happens when your brain is ready to sleep. Your brain wants to sleep, it’s going to sleep, but something from the outside is actually preventing you from sleeping. So, for example, you’re a new parent, and there’s a screaming baby waking up all night, or you’re being tortured, and a form of torture is to sleep-deprive and to keep someone awake, make a loud noise when someone is about to sleep so that they do not fall asleep. And sometimes it might be to do with having very, very lousy neighbors, which can affect sleep, things like that, in a very noisy environment, urban environment, for example.
And then you’ve got insomnia and insomnia is where you’ve got the adequate opportunity to sleep, but something inside your brain is stopping you from sleeping. So that’s two very different things. And what happens in the brain is quite different when there’s something from inside that stops you from sleeping within your own brain, and something from the outside that’s stopping you from sleeping. Now, sleep deprivation, where something from the outside is stopping you from sleeping, that’s harmful to human health. That can cause heart attacks, premature death, things like that, especially if sustained for a long time or if very severe. I don’t want to worry people about a bad night’s sleep with a screaming child is going to cause those things, but we’re talking at the most extreme end of the spectrum here.
With insomnia, actually, what happens is there’s a problem within the brain, within someone’s mind that is affecting their ability to sleep naturally. And that usually happens gradually over a period of time. And what happens is the brain actually adapts. So someone who sleeps four hours a night because they’ve got chronic insomnia will not actually have the same long-term adverse effects as someone who is having long-term sleep deprivation because the brain has actually adapted to be able to sleep less and to consolidate that sleep, that high quality sleep into a shorter space of time. So I think that’s the first thing that’s really important to actually define.
So it’s really interesting and most people, including experts outside of sleep, know this, but experts even in mental health, in psychiatry and medicine are quite shocked when I tell them this. Actually, we wake up about 10 to 15 times an hour, everyone. So this is an evolutionary thing. It’s so because our brains have changed very little over the last several thousand years, tens of thousands of years. So our brains are still adapted to if we were sleeping in caves, and we needed to be on the lookout; they’re not adapted to living in places with locked doors. So we would wake up many times, check our surroundings, make sure we were safe, and then we would go back to sleep. The same happens now. So many times an hour, you will wake up, check your surroundings very quickly, and then you go straight back to sleep. And that’s one of the reasons we never fall out of bed, because you’re constantly waking up aware of where the edge of the bed is and slightly readjusting your position.
So during sleep, we go through these sleep cycles. We go from being in very light sleep to going down into deep sleep. We call that stage three or stage four sleep. And then we come back up to light sleep again. That usually takes about an hour and a half. Then we go into REM sleep, which is the lightest stage of sleep where we’re dreaming. And then we go down again. The second time we don’t go down into the deep sleep for as long. So the most deep sleep you have is in the first hour and a half of the night.
The second hour and a half of the night you get some deep sleep and usually after that there’s no more deep sleep. So you’re just cycling between the very lightest asleep and stage two, which is still quite light and REM sleep. So that’s why you dream the most in the second half of the night and you’re in your deepest sleep in the first three hours. That’s one reason why people with insomnia, they don’t experience a lot of sleepiness because their brains have adapted to condense that good quality sleep into the first period of the night. So, actually, they can sleep a lot less than you or I.
Maybe they can even sleep for three or five hours. And you might think, gosh, how are you functioning? I would be on the floor with that amount of sleep. It’s because their brains have adapted. We’re just going back to this waking up many times an hour. So every time in the cycle, you go up to the lightest sleep, which especially in the last half of the night, you do a lot. You actually go into light sleep and then you wake up and you go into light sleep and you wake up and you’re waking up, waking up, waking up. Why don’t you remember this? So you can use the example of the confident versus the anxious driver.
So if you are a confident driver and I say to you, how did you get here today? You say, well, I got in my car, I left my house, drove along the A road and then I got here. And if you say to an anxious driver, how did you get here today in your car? They say, well, I came out my house, then there was a, almost walked in front of me and then there was a stop sign and I stopped there and then the lights went green and then I went and you would sort of, you would remember all these bits of the drive because you’re focusing on it.
If you’re a good sleeper, you wake up all these times every hour, but you don’t remember it because you fall straight back to sleep because you’re relaxed. If you have chronic insomnia, your mind has adjusted to start worrying a lot about your sleep. So what happens is you’ll wake up like everybody else, and then you’ll think, “No, I’m awake. I’m never going to get back to sleep again. That’s it, I’m done for the night. How am I gonna go to that meeting tomorrow? I’m probably gonna get fired, I’m gonna lose my job, my wife or my husband’s gonna leave me.” And of course, if you start thinking like that, you’re never going to get back to sleep. So that’s the problem, it’s not the waking up that’s the issue, it’s the staying awake that’s the issue. And I think this is actually very helpful for people to hear because if you know that waking up is not a problem, you might worry less about the fact that you have woken up.
Dr. Lauren Waterman says that the first session of cognitive behavioral therapy for insomnia CBT-I is education part, because actually, when you realize what’s going on, then you can actually change the way you’re thinking about sleep and change the kinds of things you’re doing that might be worsening or prolonging that insomnia. It’s also really important to differentiate what we mean by tired and what we mean by sleepy. So tired is usually used as a word to mean fatigued, low energy. You haven’t got the motivation or the energy to do things. Sleepy is that you feel like you’re about to drift off. Your eyes are going heavy. You feel like you’re going to off. Maybe you do nod off.
So there’s the Epworth sleepiness scale is a scale used by doctors to look at someone’s sleepiness levels. And basically all it asks is how likely are you to fall asleep in the cinema? How likely are you to fall asleep in a car when someone’s driving? How likely are you to fall asleep in a car if you were driving? So someone with insomnia, they feel tired, they feel fatigued, they have low energy. What they don’t feel is sleepy.
And just to clarify, I’m talking about people with chronic insomnia, where this has been going on for more than kind of three months, where the brain has adapted. So the problem for them is that even though they’re tired, they’re not sleepy. And that’s why they’re struggling to fall asleep. That’s one of the reasons they’re struggling to fall asleep. People with chronic insomnia, they do not drift off in the day, but they feel like they need to sleep, but they just don’t feel sleepy. And that’s the problem. So they might sometimes refer to themselves as tired but wired. So even though they’re tired, their brain is too wired, it won’t die down and it won’t let them sleep.
And part of the reason they’re not sleepy is because over time their brain adapts to not feel sleepy. And part of the reason is that there are these wakefulness pathways in the brain that are different from the sedative pathways in the brain. The sedative pathways of the brain, when there’s more activity in those, it makes you fall asleep.
And that’s what a lot of the common sleeping tablets like zopiclone and the old benzodiazepines like diazepam, that’s the pathway that they work on. But you’ve got this other pathway in the brain called the wakefulness pathway, and that deals with a neurotransmitter called orexin. And in the wakefulness pathway, things can be too active, and that might be why someone is hyperaroused and they can’t fall asleep. So even if they feel sleepy because the sedative pathways are very active, the wakefulness pathways are not dying down.
And that’s why they’re tired, but that’s why they can’t sleep. There’s actually a new medication. It’s been around for quite a few years, but it’s only in the last three years that it’s been licensed in the UK called daridorexin. And that actually works on the erexin system. It inhibits the dual orexin receptor antagonists. So actually works on. So the melatonin pathway or the melatonin cycle is to do with the inbuilt sleep-wake phase cycle of the brain.
The role of melatonin in sleep
Dr. Lauren Waterman mentions that during the day, naturally, melatonin is a hormone produced in the brain. So naturally, as you wake up, your melatonin levels go down and that allows you to wake up. And then just before you go to sleep, so in the evening, they usually increase and that allows you to fall asleep. They are affected by daylight, especially the bright white light that you get from daylight or from some light lamps, you can stimulate similar effect to reduce the melatonin. That’s one of the reasons they say that high use of screens, especially the blue light or the white light from the screens in the evening, can suppress the natural production of melatonin. I think this is probably a bit more of a problem for children and teenagers. I think there’s a bit less evidence that this is a significant problem for adults, but there’s no harm in putting filter on your phone too. So there’s many apps, for example, and I think even built into the phones now there’s options where after a certain time of the evening it can become more sort of pink red lighting rather than that blue white lighting. And that’s also why people sometimes struggle with their sleep in the winter because they’re not getting enough daylight.
So it’s really important as soon as you wake up in the morning go try and go outside if you can for half an hour have your tea outside so you get that natural light on. If you can’t go outside, you can get a light lamp. It needs to be strong enough. It needs to be at least 10,000 lumens. So needs to be bright. And it also needs to be really close to your face for about half an hour when you wake up in the morning to actually have that effect.
But going back to the melatonin cycle. So this is a natural cycle that allows you to wake up in the day and go to sleep in the evening. It’s affected by light. You also get a little bump up of melatonin in the afternoon after you’ve had lunch around three o’clock. That’s why people often feel sleepy just after they’ve had lunch. It’s quite common time that people often fall asleep on the sofa. And what the synthetic melatonin does, so the ones you can buy online, is that it acts in a similar way to the natural melatonin. So you take it at night before you go to bed, and it helps to increase the melatonin in your body so that your brain feels ready for sleep. Now, what’s really interesting is that in some countries, melatonin is sold as a pharmaceutical. It’s sold as a medication which means it’s quite heavily regulated. The body in the U.S. that regulates it would be the FDA. Actually in the U.S., the FDA does not regulate melatonin because it’s not classed as a medication, it’s classed as a food supplement, which means it can be sold in supermarkets, online, in pharmacies without prescription.
Actually, scientists have done studies on some of the most commonly sold melatonin brands, including in the U.S., and they’ve done one in Canada. And what they found was that most of these supplements had no or almost no active melatonin in them, even though on the bottle or on the box, it said that they had a certain number of milligrams of melatonin. And occasionally they actually had a lot more than they were supposed to have because they’re unregulated.
One thing that a lot of people don’t know, including pharmacists and doctors, is that melatonin supplements or medications are sensitive to light. So in the U.S., for example, they’re very commonly sold as gummies in a bottle. You open the bottle, you take out a gummy. The light hits the gummies and deactivates all the active melatonin. So, actually, even if it had melatonin to begin with, it doesn’t have melatonin in it anymore. So it’s much more important to buy them sold as sort of wrapped sachets, know, in foil sachets, like you do with some medications, in capsules, ideally, they’re light-resistant capsules. Unfortunately, I don’t think you can even really buy these in the U.S. It’s very hard to find anything like that. So, unfortunately, if you’re spending lots of money on melatonin, beware that it might not actually have melatonin in it.
