Feel Better, Live More with Dr Rangan Chatterjee - What Your Sleep Is Trying To Tell You: How To Fix Your Sleep Problems, Reset Your Brain & The Difference Between Fatigue and Tiredness with Guy Leschziner #528

Episode Date: February 26, 2025

Did you know that up to 40% of adults in Western countries struggle to get enough sleep? While some societies have historically never even had a word for insomnia, our modern world has created an epidemic of sleep problems, which affect not only our creativity, empathy, appetite and mood but countless other aspects of who we are, too.   This week's guest is Professor Guy Leschziner, a neurologist at Guy's and St Thomas' Hospitals in London and a professor of neurology and sleep medicine at King's College London. He is also the author of several books, including The Secret World Of Sleep: Tales of Nightmares and Neuroscience and his latest, Seven Deadly Sins: The Biology of Being Human.   In this fascinating conversation, we discuss: The crucial distinction between chronic sleep deprivation and clinical insomnia - understanding which affects you is key to finding the right solution The importance of sleep quality - not just quantity - and why some people can sleep for hours, yet still feel unrested An incredible treatment called CBT-I (Cognitive Behavioural Therapy for Insomnia) which has an 80% success rate for insomnia The real impact of common lifestyle factors on sleep - like caffeine, screen time, and blue light  The pros and cons of sleep trackers  Practical strategies for shift workers - discover how to adapt your sleep schedule if your work includes irregular hours The fascinating connection between societal sleep deprivation and our collective wellbeing   With over two decades of experience running sleep disorder clinics, Guy brings clarity to the often confusing world of sleep, offering evidence-based insights and practical solutions throughout our conversation.    As he points out, our sleep needs are highly individual, so I hope this episode guides you in finding the approach that works best for you.   Support the podcast and enjoy Ad-Free episodes. This January, try FREE for 30 days on Apple Podcasts https://apple.co/feelbetterlivemore. For other podcast platforms go to https://fblm.supercast.com.   Thanks to our sponsors: https://drinkag1.com/livemore https://vivobarefoot.com/livemore https://exhalecoffee.com/livemore   Show notes https://drchatterjee.com/528   DISCLAIMER: The content in the podcast and on this webpage is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or qualified healthcare provider. Never disregard professional medical advice or delay in seeking it because of something you have heard on the podcast or on my website.

Hey guys, how you doing? Hope you're having a good week so far. My name is Dr. Rangan Chatterjee and this is my podcast, Feel Better, Live More. While some societies have historically never even had a word for insomnia, our modern world has created an epidemic of sleep problems, which not only affect our creativity, empathy, appetite and moods, but countless other aspects of who we are as well. This week's guest is Professor Guy Leshner, a neurologist at Guy's and St. Thomas' Hospital, and a professor of neurology and sleep medicine at King's

College London. He's also the author of several books, including The Secret World of Sleep and his very latest Seven Deadly Sins, The Biology of Being Human. In our conversation, we discuss so many fascinating topics including the crucial distinction between chronic sleep deprivation and clinical insomnia. The importance of sleep quality, not just quantity, and why some people can sleep for hours yet still feel unrested. An incredible treatment called CBTI, which has an 80% success rate for insomnia.

The real impact of common lifestyle factors on our sleep, like caffeine, screen time and blue light. The pros and cons of sleep trackers. Practical strategies for shift workers. And the fascinating connection between societal sleep deprivation and our collective wellbeing. With over two decades of clinical experience, Guy brings clarity to the often confusing world of sleep. And as he points out, our sleep needs are highly individual. So as with everything I speak about on this podcast, it's important that we all find the

right approach for us. In The Secret World of Sleep, towards the end, you say that when you look at your patients and your daughter, it's obvious why we think of wake and sleep as entirely different states of existence with clear borders, a reinforced concrete barrier, the Berlin Wall separating the east of sleep from the west of wake. So I guess my question is, what is the difference between those people who can walk through that Berlin wall from wake to the state of sleep compared to those who are really struggling to do that? Oh, that question has got a number of different answers to it. I think the honest answer is that that view of that concrete

wall is totally incorrect because we know that our brains are constantly sitting somewhere in the spectrum of wake and sleep and that different parts of our brain can exist in different stages at the same time. So you and I at the moment while we're talking, there are little bits of our brain that actually are sleeping. There are little islands of sleep. So I think the, so that's the first sort of answer. The second answer, and I think you were specifically referring to those individuals who struggle

to get off to sleep. Well, we know that there are important psychological factors at play. Now, some of those are conscious psychological factors. So things like anxiety, frustration, dread of the night ahead, worry about how you're going to be able to perform the following day. But I think we as doctors get very fixated on the fact that if somebody's not sleeping, they must be anxious or they must be depressed. But we know that 50% of people who have insomnia don't have any issues with anxiety, don't have any issues

with depression. And so in those individuals, we know that there are a number of unconscious psychological factors that stop them getting off to sleep. We think of these individuals as having, and I include myself in that group, I definitely know what it's like to struggle to get off to sleep, is that there are certain factors that we associate in our life, in our environment, that we associate on an unconscious level with being able to drift off to sleep with sleeping well. But for individuals who've had chronic sleep difficulties, those factors, like being in the bedroom, being in the bed,

being surrounded by the environment that we inhabit at night, is associated with staying awake rather than being asleep. A sort of Pavlovian conditioning is what we term it. And so there are all these different factors at play that give rise to, as you say, traversing from the west of wake to the east of sleep. Although, I guess, technically it may not be fully correct in the sense that you're

either fully awake or fully asleep. I thought that bit of writing was very evocative. This idea came up for me that there's a gate and so many people can walk through that gate every night and often they're ignoring the sleep hygiene advice, right? So they effortlessly fall asleep no matter what they do. And so to them they probably don't even think that there's a gates there. They're just like, well, yeah, it's bedtime.

I go to bed, I'm going to go to sleep. But some people are trying to do everything they possibly can. And despite their very best efforts, that door remains locked, doesn't it? Yeah, we focus very much on sleep hygiene. It's all over the social media. So just to clarify what sleep hygiene. It's all over the social media. So just to clarify what sleep hygiene

means, it's essentially describing the behaviours that are conducive to a good night's sleep. And a lot of it is common sense. You know, avoiding caffeine late at night, avoiding nicotine, making sure that your bedroom is quiet, making sure that it's at the right temperature, making sure that there's nothing in your environment that might disrupt sleep, getting exercise during the day. So, you know, often people will go to their GP and say, look, I've got insomnia, and they will be told, well, you need to source out your sleep hygiene.

You need to put these steps in place. But as you say, the difference between somebody who sleeps very, very well and somebody who has chronic insomnia is often nothing to do with sleep hygiene. It's an entirely separate issue. It's about the fact that after a little time, when you start focusing on your sleep, then actually sleep becomes more difficult. Yeah. What do we know about our evolution in terms of tribes and their ability or inability to sleep and how does that compare to our modern urbanized lives? Well, certainly there have been quite a lot of studies looking at

sleep in in pre industrial societies, hunter gatherers, for example, in Tanzania or tribes, people in South America. And actually, you know, there are some tribes that don't even have a word for insomnia. They don't have that difficulty in getting off to sleep. So there's clearly something about modern life that I think has accentuated a problem or created a problem. One of the obvious issues is that we have no longer become in tune with the sunrise and the sunset. And of course, the sun is the biggest influencer of many of the cycles, many of the rhythms within our body, the circadian rhythm. But also there are lots of pressures of modern life that perhaps drive that tendency towards insomnia that many of us have. Yeah. If I think about your career, so you're here in London, Guy's for St. Thomas's, you

run a sleep disorder clinic and have them for many years. It's quite a contrast, isn't it, where we think about these pre-industrialized societies, some of them don't even have a word for insomnia. Yet, how many diagnoses do we have for people who can't sleep? How many different things do you see in your sleep disorder clinic? It's quite a stark contrast, isn't it? Yeah. I mean, some of the things that we see in our clinics that preclude people from sleeping

well have a fundamental biological process underlying them. And it's likely that those biological processes have always existed throughout the history of humankind. So when we see some individuals who, for example, have difficulty staying asleep or have unrefreshing sleep, they may have biological or structural anatomical reasons for why they might do so. Conditions like obstructive sleep apnea, whereby the airway collapses down in sleep. Now, obviously, to some extent, these sorts of conditions are associated with modern life. Obstructive sleep apnea is associated with weight gain, but obstructive

sleep apnea occurs in individuals who are not at all overweight and so are likely to have been present throughout human history. Other neurological disorders that prevent you from having a good night's sleep have probably also existed. It's just that historically we haven't had the tools to make these kinds of diagnoses, or we haven't understood the basic biology of sleep, which is really still in its infancy. So, you know, what you have to remember is that for the vast majority of human history, all we've had to understand sleep is our own subjective experience of sleep. And our subjective experience of sleep can, in some cases, be really quite dramatically different

from objective measurement of sleep. I guess one thing societies have tried to do for many years is explain the meaning of dreams. As someone who is a sleep expert and has seen what can happen to the brain and from the brain when people are asleep. What's your perspective on the reason why we dream? So I think that there are probably multiple reasons why we dream. You know, people often ask, well, why do we sleep? And I think there are multiple functions of sleep. You know, we know that

sleep is not only about one thing, it's a sort of housekeeping state for a range of physical and neurological functions. So to say, well, there's one reason for why we dream is probably not going to turn out to be the case. I think that there are two major, actually there are three major potential functions for dreaming. One you probably will have heard of from people like Matthew Walker, which is this view that one of the functions of dreaming is to process the emotional content of certain memories, and Matthew describes that as overnight therapy. And we see that very frequently in our clinics in individuals who have had significant traumatic experiences

and have PTSD, whereby they relive aspects of their original trauma over and over, overnight, for that process never to complete. But it's likely that the other aspects of why we dream are probably more neurological rather than psychological. So one of the important functions of dreaming, of this state of sleep that we most associate with dreaming, which is called rapid eye movement sleep, is the shifting of information from areas of the brain that are responsible for taking in memories in the short term and consolidating those memories elsewhere within the brain. The other, I think, very attractive proposed function of REM sleep is that this is about

tweaking the model of the world that we have within our minds. Because in order for us to perceive the world as it is, we need to have a model. Our brain is a prediction machine. It's an expectation machine. We have to have expectations of how we expect the world to be. Now, how do we adjust that model of the world? Through dreaming every night, through taking in those bits of information that we've acquired over the course of our preceding day, preceding weeks, months or years, and adjusting that model when we're in that offline state. I imagine you will have seen some cases over the years where their dreams, where your patients dreams have been quite problematic in terms of the impact they're having on their lives. Absolutely. I think at the sort of least extreme end of the spectrum are

individuals who have narcolepsy, which is a neurological disorder whereby their REM sleep is a little bit abnormal. And those individuals will often have fascinating lives, alternate lives at night, because their dreams are very realistic. They will often continue throughout the night. And, you know, I've occasionally had patients say to me, well, look, I live an entirely different life at night to what I live during the day. My dreams are so realistic.

I have this alternative life that I'm living. At the real extreme are those individuals who have terrible nightmares associated with really major traumatic experiences that disrupt their sleep to such an extent that it has a really very significant impact on the quality of their lives. Wow. You mentioned dreams there and nightmares. Are dreams the umbrella term and nightmares are a form of dream? Yeah, so nightmares are dreams with a negative emotional content. I mean, I think it's also important to stress that we associate dreaming with this stage of sleep called rapid eye movement

sleep. But actually, we know that we dream in other stages of sleep as well. So we dream in non-REM sleep as well, which is why, for example, some people may have memories of certain fragmentary dreams associated with conditions like sleepwalking or sleep talking, for example. It's the nature of those dreams that is rather different. So in REM sleep, you know, what we used to term dreaming sleep, it's those dreams of a narrative structure, something evolving over time, you know, like the plot of a film. Whereas in non-REM sleep in conditions like night terrors or sleepwalking, for example, often these are very brief snippets, sometimes with very strong emotions.

And so if you're talking about dreams in general, you know, there are many people that I see who do some really quite scary things at night in the content of their sleepwalking or night terror episodes. I've heard you talk before about some criminal activities that can sometimes take place when people are asleep. Really, I guess, highlighting the title of your book, The Secret World of Sleep. I think for many of us, it just seems that while we sort of close our eyes, we go to sleep and at some point we wake up and, yeah, we might have dreamt, we may not have dreamt,

we may have dreamt and not remembered it. And then we get up, have a coffee and get on with our day. But this idea that once you've gone to sleep, once you've gone through the gates, that all kinds of other stuff can happen, including criminal activity, I think that's pretty striking. Yeah, it is. Obviously for most of us, our experience of sleep by and large, apart from those situations when you remember a dream, is that your brain switches off and then switches on again when you wake up in the morning. Whereas that's very far from the truth. In fact, there are certain

stages of sleep during which our brains are very highly active, as active as they are during the day. So not only on a sort of scientific basis is that switching off the brain incorrect, but also on what people experience can be very far from that as well. Individuals who will walk in their sleep, who will drive in their sleep, who will, you know, I've seen a patient who rode her motorbike in her sleep. And then there are individuals who will perform violent acts in their sleep that can result in conviction. If we try and look at sleep and the kind of things we're talking about through an evolutionary

lens, what is the purpose of being able to do certain things and activities when we're asleep? do certain things and activities when we're asleep. Is it a normal function that's gone slightly malfunctioned in the modern environment? I'm not sure. So for example, when you take conditions like sleepwalking or night terrors, I'm not sure one can propose a particular evolutionary purpose to them. So obviously there is some benefit in when you are in very deep sleep and something around you causing a partial awakening that has potential benefits. So when we were sleeping in the wilds and a saber-toothed tiger went past and made a noise, obviously it would be beneficial to be able to wake quickly from very deep sleep.

But I don't think that explains these phenomena particularly well. I think it's a glitch in the system. So not all of us are able to generate these kinds of phenomena. Actually, many of us, if our brain is given enough provocation, can actually have a sleepwalking episode. So just to give you an example, I occasionally see individuals who have never sleepwalked or sleep-talked or done anything odd in the night, and then they're started on particular drugs, and all of a sudden they

begin having some very bizarre phenomena at night. So, you know, all of us to some extent, if we had enough medication, if we were sufficiently sleep deprived, if we had sufficient alcohol poured down our necks, could potentially generate this. But it's not a normal function. It's a glitch in the system. There's a bit of research now, isn't there, supporting the idea that certain chronic conditions, let's say Parkinson's, potentially the architecture of your sleep, potentially your some dreams that you may get maybe decades beforehand might indicate or I guess you could say might be warning you of something imminent that's about to come. Is that quite new, that research and what's your take on it?

So this this idea, particularly with Parkinson's disease and associated conditions, has been around for a little while because we have known for probably 15, 20 years that in certain degenerative conditions of the brain, there is what's termed a prodrome. So even before people exhibit the frank symptoms of conditions like Parkinson's disease, many years before, they may well show changes in terms of their smell. Constipation, for example, increased levels of anxiety. But what we have realized over the last 10 or 15 years as well is that many people, sometimes up to 30 years before they develop Parkinson's disease, will develop a specific type of sleep disorder, which is called REM sleep behaviour disorder.

So as the name suggests, it arises from REM sleep, that stage of sleep that we associate with dreaming, these dreams of a narrative structure. But normally in REM sleep, whilst our brain is very active, our muscles are completely paralysed. In fact, the only muscles that maintain some degree of movement are the muscles that control our eyes, which is why it's called REM sleep behavior disorder, and some of the muscles that help us breathe for obvious reasons. So what we often see in individuals who subsequently go on to develop Parkinson's disease or related conditions is that mechanism of paralysis doesn't work properly and they begin to act out their dreams. They begin to show, particularly in aggressive

dreams, some movements that are very much in keeping with them defending themselves or fighting off people. And so we are involved in a number of different studies at the moment whereby we are taking individuals with these kinds of conditions and trying to plug them into more detailed studies of their nervous system to characterise their movements, their thought processes, their handwriting, to try and gain some predictive power as to who is likely to develop Parkinson's disease in the next three or five years. So not everyone who has these particular sleep disorders is going to develop Parkinson's disease in the next three or five years. So not everyone who has these particular sleep disorders is going to develop Parkinson's,

but it's going to be a subset of them. Well, we used to think that for the majority of individuals, people who exhibited this condition, largely it was of no particular relevance. It was termed idiopathic, which is, as you know, the sort of medical term for, well, we don't really know. It doesn't seem to have any association. What we've now begun to appreciate is quite how high the risk of developing conditions like Parkinson's is. So if you develop this kind of phenomenon, particularly later on in life, then your likelihood of developing Parkinson's disease or conditions like it is very high indeed. So some studies have suggested rates of as high as 90% over 15 years. What we don't yet know is how quickly you are likely to develop these kinds of conditions. It's important

to say that people shouldn't panic if they develop these kinds of things because we know that there are other things that can also trigger dream enactment behavior disorder, like antidepressants, for example, and occasionally we do see it running in families. So it's not a given that if you start acting out your dreams later on in life, then you will necessarily develop Parkinson's disease. It's fascinating that if we think about us as humans and the purpose of sleep and the fact that certain indigenous tribes don't have a word for insomnia and so from what we can tell didn't really have an issue with not being able to sleep. What's the state of sleep deprivation today across let's, the UK or the US or whatever, you know, research you're familiar with?

And then I'd love to understand from your perspective, what are the common things going on in modern society that are possibly getting in the way. So we know that about 20 to 30 percent of adults in Western countries are not getting enough sleep. So that they have what's termed insufficient sleep syndrome, used to be called a behaviorally induced insufficient sleep syndrome, essentially meaning that they are sleep deprived. Now for those individuals the answer as to why they are sleep deprived is entirely driven by lifestyle. It's the fact that we're juggling too much, that we're socializing too much, we're working too long hours. It's important to stress that that cohort of individuals who is sleep deprived is

very different from those individuals who have insomnia. There is an intrinsic difference between sleep deprivation and insomnia. So do we sometimes use those words interchangeably, incorrectly? Yes, absolutely. Okay, so this is really interesting. So just to give you some really obvious illustrations of that is if somebody is sleep deprived, either not getting enough sleep for what they need, then they will typically be rather sleepy

during the day, they will drop off to sleep when given the opportunity. In contrast, individuals with insomnia, by and large, no matter how little sleep they've had at night, they will find it very difficult to sleep during the day, because the same thing that is preventing them from getting off to sleep at night is also present during the day. It's also important to stress that a lot of people with insomnia, when we objectively measure their sleep, their objective total sleep time, so the amount of minutes that they're sleeping at night is often not that dissimilar to entirely normal sleepers. It's about the subjective experience of sleep. And so it

goes back to what I said earlier, which is that the objective measures of sleep and the subjective experience of sleep are often vastly different. I occasionally see people who say I didn't sleep a wink at all on the night that we did the sleep study, but we record eight and a half hours of beautiful sleep on the basis of their brain waves. And also the health risks associated with chronic sleep deprivation and insomnia are also somewhat different. So these are two very different conditions. They're two very different states. And there's a little bit of overlap which we can get into. But how many people would you say out of a hundred, if 20 to 30% are struggling with chronic sleep deprivation,

what's the percentage who is struggling with insomnia? So about 10% of the adult population in Western countries have chronic insomnia. Chronic being defined as having regular issues with difficulty getting to sleep, staying asleep or unrefreshing sleep on a regular basis for more than three months. So can we say that based on what you just said, up to 40% of the population are seemingly having difficulty getting enough sleep, whether through chronic sleep deprivation or through

insomnia? Yeah, it's an awful lot. It's a lot. And as you'll know from sitting in your GP clinic, sleep often comes out as the highest complained about medical issue when people come to their GP. So something like 70% of people will mention their sleep in a GP consultation. So whichever way you cut it, sleep issues in the modern world

are a huge problem. Okay, so you mentioned, you know, chronic stress, working too much, not switching off enough, we're socializing loads, whatever it might be, there's all kinds of factors that I think a lot of people certainly listens to this podcast probably are aware of. What are some of the common misconceptions you find about sleep? Sleep is all the rage these days in the health and wellness worlds. So I think like most things, there's an upside and there's a downside. So the upside of all of this education on sleep over the last few years is I think that more people

are taking sleep seriously and realizing, oh wow, maybe I should not stay up till midnight, five nights a week. Maybe I should try and go to bed a bit earlier, et cetera, et cetera. The flip side of course is all this awareness on sleep is stressing the hell out of people who can't sleep, whether that's because they're young parents or whether because they've got

chronic insomnia. Yeah. So, look, you're absolutely right that people like me are a bit of a double-edged sword because, you know, it's a very fine balance to make sure that people have an appreciation of sleep and its importance for our general health, our physical, psychological, neurological health, but without scaring the hell out of people and giving them misconceptions about what they should expect. One of the commonest misconceptions is that a lot of people with insomnia worry terribly

about the consequences, the long-term health consequences of their insomnia worry terribly about the consequences, the long-term health consequences of their insomnia. And as I sort of already alluded to a little bit is that those kinds of health issues are really only relevant to a very small proportion of individuals with insomnia because most people with insomnia, their qualitative experience of sleep may be poor. They may feel that they are spending prolonged periods awake at night. But actually, if you measure their total sleep time overnight objectively, it's not that different. And for those individuals, the kind of consequences that we talk about, things like blood pressure issues, cardiovascular disease, stroke, do not seem to apply at all. There have been some really good studies that have come out of Penn State in the US that have suggested

that those long-term health consequences are not relevant for the majority of people with insomnia. Are you specifically talking about insomnia here as opposed to chronic sleep deprivation? I'm specifically talking about insomnia. Okay, could you just give us a list of maybe sleep disorders that come under the umbrella of insomnia? Just taking a quick break to give a shout out to AG1, one of the sponsors of today's show.

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Just wanted to take a moment to tell you about my first ever UK theatre tour taking place this March. So I've just finished two days rehearsing for the show with the entire tour team, the director, video tech, sound crew, tour manager, and I'm even more excited for these live shows than I was when I first announced the tour. Now if you enjoy listening to my podcast, I think you are going to love coming to this tour. Don't think of it like a book tour. Think of it as an immersive, transformative, fun evening where you will walk away with a personalized blueprint of

the things you need to work on in your own life. It's not just me on a stage talking to you. There will be lots of interactive moments and a few surprises. Now, I know that many of you listen to this podcast to learn things that will help you thrive. But I also know that at times it can feel hard. On this tour, you are going to be in a room with other people who are interested in the same things as you are, which will feel incredibly special and give you a massive boost. These events are going to be fun, inspirational, educational and hopefully will be the springboard you need to take action as we move out of winter and get into spring. There are 14 shows all around the UK. The two warm-up dates in Wilmslow and the London

Lyceum date has just sold out. So don't delay if you plan on picking up tickets. All details can be seen at drchattygy.com forward slash events. So get your friends together, make a night of it, and I hope to say, look, insomnia essentially describes the fact that when you are tired and you want to sleep, you either can't sleep or your experience of sleep is unrefreshing. Now, that's a very broad definition and really doesn't help that much because there are lots of other conditions that can cause a very similar clinical picture. You know, anything that disrupts your sleep, be that drugs or sleep apnea or neurological disorders can give rise to

that. But in the absence of features to suggest that you've got one of these conditions and that you haven't got a drug that is causing your sleep to be disturbed, it remains a bit of a bucket term. But it is very distinct from sleep deprivation because people with sleep deprivation, when they are in bed and they want to sleep, they can sleep. It's just that they're not spending enough time in bed. And so they are sleep deprived and are sleepy as a result. So, very, very different. So when I'm talking about these kinds of health issues and misconceptions about it, I'm specifically talking about insomnia where people feel that they have difficulty getting off to sleep

or staying asleep or that they feel that they don't achieve a very deep sleep. Those individuals, the majority of them will not be at risk of some of these issues that have been highlighted in social media. Why do you think that's the case? Because if it's just to do with sleep and how much sleep we're getting and the quality of that sleep, one might think that whether the cause of that sleep deprivation is chronic sleep deprivation or insomnia, you would think that the health implications are going to be the same. So why do you think it's different

if it's one of these insomnia conditions? Well, I think there's two potential explanations for that. The first is that, you know, again, and I'm trying not to sound repetitive, but the fact is that we are not very good witnesses to our sleep. And so a lot of people with insomnia, actually, they're getting much more sleep than they think they're getting, okay? There is something also really rather fascinating in that we know that, you know, we talked a little bit about the brain being able to exist in different stages of sleep and wake at the same time. And there is some evidence that actually, you know, for example, there's

this entity called paradoxical insomnia, which is individuals who actually feel that they've slept very little, but when we record their sleep, they're sleeping huge amounts. Okay. Now, you know, that we used to consider that as being psychological, but actually there is quite good data now to suggest that actually what's happening is that whilst the majority of the brain is asleep, the parts of the brain that are responsible for consciousness, for awareness are not going into quite as much deep sleep. So it is likely that for people who have insomnia, some parts of the brain, or indeed the majority of the brain, is achieving reasonable sleep. It's just that certain parts

of the brain may not necessarily be achieving as deep sleep as you would like. So that's one reason. We also know that the chemical effects in terms of hormones is different for people who've got behavioral sleep restriction, who are sleep deprived versus those individuals with insomnia. There is undoubtedly some overlap. So those individuals who've got true insomnia with very, very short sleep times do seem to have some risk associated with them.

But for the majority of people, that's not the case. Okay, so is the take home, for some of us at least, that if we are chronically sleep deprived because of the choices we are making in our life, maybe I should rephrase choices because many people feel that they don't have a choice and that they're, you know, they've got to work two jobs, they're stressed out, they've got too many things to do,

and what often gets compressed, it's that sleep opportunity time. But are you essentially saying that if it's not insomnia, right? So if it's to do with the way you're living your life and you're not getting enough sleep for whatever reason, it's likely that chronic sleep deprivation over a number of years is going to potentially lead to all kinds of negative health outcomes. Yeah. And many of the things that you see in your GP practice. Well, so what you say though about objective data versus our subjective experience, that's

really, really interesting. So let's take one of those patients, right? Who has got chronic insomnia and they end up at your clinic and you bring them into the sleep lab and then you show them the next day, hey, listen, you don't think that you're sleeping well, but let me show you, look how good your sleep is. What is their usual response to that? Well, I think it depends on the underlying cause. There are some individuals who point blank accuse me of having switched their sleep study for somebody else's, who simply cannot

understand that that is the case. And occasionally we do see patients who have got profound mental health issues, conditions like psychosis, in whom that sort of experience of sleep is part and parcel of their psychosis. I think that a lot of people are really open to the view. And I think particularly now that we have some sort of biological explanation as to how these phenomena may arise, it can be very helpful. Now, it doesn't detract from the fact that that doesn't suddenly cause their symptoms to evaporate. Their symptoms

are very real. But it opens the possibility of actually trying to improve their sleep. Because first of all, one can at least stand back and say, look, I don't think you've got as much reason to be worried about the long term consequences of your sleep patterns as you originally thought. You can imagine if you feel if your experience of sleep at night is that you haven't slept a single minute, then people convince themselves of all sorts of things. So to be able to say to somebody actually, you know what, yes, your experience of sleep is poor, but actually your objective sleep is not that bad in itself can be sometimes rather helpful.

But it also raises the possibility of using some techniques, not necessarily drug-based techniques but also some non-drug-based techniques to try and improve their subjective quality of sleep. Given that our experience of being human is fundamentally a subjective experience, could it be argued that all that really matters is how we feel after we've slept? I'm not denying that there are physiological implications if we're not sleeping enough. But for example, if you

are biologically, measurably getting enough sleep, but you don't think you are, that's going to have a certain consequence on your experience of day to day life. Whereas if it's the other way around and you are not biologically getting enough sleep, but you think that you're rocking it and actually your sleep is fantastic and you can do all the things that you want to do. Like I think I know which one I'd rather have. Yeah. And I think that this is a, you know, one of the difficulties in sleep medicine. So there are some people who get very fixated on objective results. There are other people who say, well, the objective results don't

matter at all, that it's the subjective experience. I think the honest answer is it's somewhere in between. And so, which is one of the reasons why I think that, you know, whenever you bring in somebody for a sleep study, it's important to interpret that sleep study in the context of what it is the individual sitting in front of you is telling you. It's no use being led purely by the sleep study. It's no use being purely led by what the you is telling you. It's no use being led purely by the sleep study. It's no use being purely led by what the individual is telling you, although sometimes actually it's probably the right thing to do. And that is part, as you know, part of the art and the science of medicine

is trying to get a holistic view of the person sitting in front of you. And of course that applies beyond sleep medicine. Treat the patient, not the test results. Yeah. Right? So that's ultimately… That applies in sleep medicine as well. And you know, sometimes the test results can be wildly inaccurate because, for example,

if I think that somebody may have narcolepsy, which is a neurological disorder that causes them to be profoundly sleepy, and without asking them any questions, bring them into a sleep lab and do the test, it'll come back positive in about 2% to 3% of individuals. Whereas narcolepsy is a very rare condition, it only affects about one in 2,000, one in 3,000 individuals. The rest of those individuals are sleep deprived. And so, you know, you need to, before you do a test on somebody,

you need to understand what it is you're testing for and what the situation is that you're testing in. Sleep laboratories fascinate me for a number of reasons. One of the things I've been thinking a lot about recently is, which I'm sure you guys are on top of in your fields, but this idea that you're trying to assess what is happening with a patient in the context of their everyday lives, but you're not measuring them in their home environment, in their beds, in their bedroom, in their house. So what is the current thinking as to how applicable and how relevant the test results

in a laboratory are to what's going on in a patient's house? Yeah. It's important to stress that even if you do the sleep study in somebody's house, the fact is that you're covering them in wires, you've got a video camera set up in their bedroom, that is not going to replicate a normal night's sleep either. But also, the people's response to being in that situation tells you quite a lot about what the underlying mechanisms are for their sleep disturbance. What I mean by that is, look, for people who've got very severe sleep apnea,

whether or not they're covered in wires, whether or not they're in a home environment or, you know, within the sleep lab, they will not have that much of an impact of being studied. If somebody's got insomnia and you bring them into a foreign environment, you need to cover them in wires, then the likelihood is that they're going to sleep very poorly indeed. And so it's that response that also gives us some further information. It's important to stress additionally that actually for most people with insomnia, we don't do sleep studies because it's unhelpful. You know, we often record a very poor night's sleep and sleep studies in the context of studying

insomnia have a very specific role, which is if we think that there might be something else going on with their sleep, then it's to exclude those other possibilities. And for a few selected cases, it's about saying, well, look, actually, your situation is that you've got this condition like paradoxical insomnia, which is helpful in terms of moving things on. But the vast majority of individuals with very clear cut insomnia, a sleep study is unnecessary. Yeah. And, you know, the other aspect of all of this is, look, you know, we're recording a single night, all of our sleep varies from night to night. And so we're getting a snapshot.

And all of these factors need to be taken into account when you're interpreting the results of a sleep study. Again, you have to reflect on what it is the person is telling you, rather than simply focusing on the sleep study as being the absolute gold standard way of understanding everything about one person's sleep. Is that where perhaps sleep trackers can come in? There's pros and cons, which we can talk about, but one of the benefits I would imagine is

that a sleep tracker, one of these modern high-tech health wearables, is typically worn by a patient in their own house, in their environments. They are minimally invasive. There's not all these electrodes on their brain. So, I guess one of the upsides is that you're getting maybe a better and more accurate reflection of what is typically happening. Yes, absolutely. You're getting what we term longitudinal data. So you're getting multiple bits of information across days, weeks, months or years. There are a number of specific questions about sleep tracking technology. The first is, you know, how reliable is it? And we, you know, obviously the technology is changing all the time. And so this is a changing playing field. But certainly there are significant concerns about

the accuracy of certain aspects of what sleep trackers are telling us. The other issue is that they, for those that have been validated, that have been sort of compared to gold standard ways of monitoring sleep, they usually have been validated in normal individuals who sleep normally. So if you have an issue with your sleep, be that insomnia, be that sleep apnea, be that restless leg syndrome, then the validity of what the sleep tracker

is telling you is uncertain. So look, there are some distinct advantages, but the question that you have to ask yourself is why am I wearing that sleep tracker in the first place? Because if you're wearing that sleep tracker because you've got insomnia, because you're already concerned about the fact that you can't sleep, then I think wearing a sleep tracker is potentially very bad for your sleep rather than good for your sleep. Towards the end of your book on sleep, you mentioned that the two commonest questions

you get in your clinic are, how do I know if I'm getting enough sleep and should I get a sleep tracker? So let's tackle both of those head on. If your patients are thinking that, I imagine most of the listeners, or many of the listeners are also thinking that. So how does someone know if they're getting enough sleep?

Yeah. So there is no magic number. You know, we kind of typically say that on a population level, somewhere between seven and eight and a half hours is optimal. But each of us have different sleep requirements and our sleep requirements depend upon our age, our genetics, and also whether we've got anything else that's disrupting our sleep. So the key question you need to be asking yourself is, am I going to bed roughly at the same time and waking up at roughly at the same time every day? Am I lying in for more than a couple of hours at the weekend? Because that probably suggests that you're not getting enough sleep during the week. Am I waking up feeling refreshed and able to maintain wakefulness throughout the day? And am I then ready for bed at my routine time? If all of those answers are yes, then you're getting enough sleep for you generally.

Yeah. You mentioned that I'm able to maintain wakefulness throughout the day. maintain wakefulness throughout the day. Many cultures around the world, of course, choose to nap. Okay. So how does the need or the desire for napping fit into that question? Because if you choose to have a nap, it may be that that's what you're habituated to doing. It may be that you don't necessarily need to have one, but you're choosing to. So how might someone who naps answer that question? So I think you mentioned this term, what you're habituated to. So this is about routine. So if your routine is, look, we know that our circadian rhythm has this dip after lunch

anyway where we're more likely to feel a little sleepy. And if that is part and parcel of your regular life, then there's nothing wrong with that. I think, in fact, there is some good evidence that a siesta is quite good for your afternoon blood pressure, for example, that it sharpens you up a little bit. I guess, you know, again, it comes back to this view of routine and whether or not your patterns

are stable or not. Interestingly, you know, in Spain, which has, I think the siesta culture is dying out a little bit, if you add up their total sleep time, they are some of the shortest sleepers in the whole of Europe. Really? So even with that siesta,

they're not necessarily catching up to the Germans or the British in terms of how much sleep that they're getting. The life tends to be a bit more nocturnal because at night it's cooler and they can get on with their day-to-day activities. But I suspect that that sort of nocturnal culture has been driven a little bit too much and has resulted in people being sleep deprived. Yeah. Okay. So those questions are really helpful. So we can all ask ourselves those questions to determine, are we getting enough sleep? And what I love about that is it's highly individual.

It doesn't require us to go, am I hitting eight hours or 7.5, whatever it might be, which of course, you know, we can't say that there's one number for each and every single person. In terms of that second question that you commonly get asked about trackers and wearables. You've touched on some of the ideas already about the potential benefits when it's in someone's house. You've talked about accuracy.

Is it fair to say that you are seeing a lot of patients who have chronic insomnia, who their inability to sleep is playing havoc in their life. And so I would guess that sleep trackers in that population might not be the best thing. Yeah. I think the question to ask oneself is when you're poised to click on the link for the Whopper or the Apple Watch or whatever it is that you're wanting to purchase is, why am I buying this? Okay, if I'm buying it because I'm anxious about my sleep and I have difficulty getting off to sleep, then I would argue that to click that button is the wrong decision for you. Because what tends to happen is that if you are

already worried about your sleep, if you're already worried about your insomnia, and you get a piece of kit that forces you to focus even more on your sleep, that may give you data that worries you, regardless of how relevant that data is, then actually that might make your sleep even worse. If you're one of those individuals who generally you kind of you're one of these individuals who likes measuring their life, you don't have an issue with sleep, you want to try and understand the correlation between how much of an opportunity you give yourself to sleep and other parameters, then I don't think there's anything wrong with it. Would I do it myself? Probably not, because I'm more interested in my own subjective experience of sleep. But I don't think it's harmful. And for some

individuals it can be very beneficial, because if they very clearly realize that, okay, on the nights I sleep six hours, you know, I'm functioning like this, on the night I sleep eight hours, I'm functioning like this, then it'd be quite useful in terms of causing them to focus a little bit more about giving them the opportunity to sleep more. Yeah. I love that perspective. I mean, my view is that these things are just tools and it's our relationship with the tool that ultimately determines its impact on us. Yeah. It's also about something else, which is about, you know, once you have the data, what do you do about it? And so unless there is a clear outcome that allows you to improve your situation, you want to have to wonder about why one is measuring this.

Yeah, I think all these things as they come into society, they shouldn't be blanket things that we all suddenly jump into. I think they can be really problematic at the same time, they can be really helpful. So my own, I guess, journey with sleep trackers was, I don't know how many years ago now, I did buy an aura ring, probably when they first came out, six, seven, maybe eight years. I can't remember what it was now. And I'd wear it for a while. And after a while, I thought I've kind of learned what this thing is teaching me. Two big things I learned back then were any alcohol

in the evening seemed to have quite a significant impact on the quality of my sleep, which I could probably have told you anyway without that. That was what I was gonna ask. I also learned for me that if I could keep my dinner time away maybe by two or three hours from my go to sleep time, the quality of my sleep would improve. Okay. Again, which I could tune into and feel.

So I stopped wearing it. And so I just thought, okay, I've learned what it is. I've learned two powerful things, I think, which have helped me change my behavior. I don't need it anymore. But over the last few months, and probably this was prompted, I spoke to Kristin Holmes, who's the, I think she's the chief science officer at Whoop. Had a great conversation with her on this podcast. And I thought at

the end of it, you know what? I'm just going to try the whoop bands, but I'm a very different person from four or five years ago. I can be quite detached now from data. And so I feel I've got a very healthy relationship with it. I feel that's been very interesting for me. And I'll tell you why. I don't think it is for everyone necessarily, but I don't really look at the sleep stages on it. What I find interesting is the amount of time, at least it's reporting I've slept for, but I don't want to get reliant or dependent on any wearable. So I use it as a way of tuning into myself. So each morning, if I choose to look and I don't always, I try and guess what is my HRV? What was my

readiness score? So I'm trying to like, I'll do a meditation and I'll sort of go, okay, how do I feel today? You know, what is this? And I find I'm getting more and more accurate with my interpretation of what's going on. So to cut a long story short, in essence, I believe that for me, it's helped me tune into myself more. So it's given me a bit of objective data and I'm comparing that with how I feel. But again, I don't look every morning. And if I see a poor sleep score,

it's not going to negatively affect me in the day. I don't know your take on that. So look, I think what you're saying is that not everybody is the same. Absolutely. And that's the case throughout medicine, throughout society. And so, this is why I'm always cautious about

the one rule for everyone approach. It's just not productive. We are all different. We have different needs. We have different personalities. We have different preferences. For some people, there are tools out there that if they are used properly and are interpreted in the correct context can be very, very useful indeed. There are other individuals out there for whom these bits of kit, these tools, are absolutely destructive to their sleep. And it's knowing where you are and what your motivations for using these kinds of technology that's important. Matthew Kemp Yeah, I would say even in my own family,

my wife and I have completely different perspectives on this. I don't think it would suit her, which I think it's suiting me. What's interesting, Guy, if I think about the two books of yours that I've read, The Secret War of Sleep and the new one, Seven Deadly Sins, which I'm making my way through. It's interesting for me to know how you got from sleep to writing about the seven deadly sins. So could you just describe your thinking, basically what led you to this newest book? Well, I think there's two things to say is basically all the stuff that I've written

takes the extremes of the human experience, takes individuals who have severe neurological problems and try and put them in the context of what it means for all of us. And as well as being a sleep physician, I'm also a neurologist. I run a weekly epilepsy clinic, I do general neurology clinics, and I see a lot of individuals

in the context of my clinical work in whom their behavior has been changed by neurological disease or sometimes psychiatric disease. And so really this is an extension of the clinical work that I do. So about 50% of the time I'm sitting in the sleep clinic, about 50% of the time I'm sitting in a neurology clinic. And this is the other side of my clinical practice. Yeah. I've always loved to examine the extremes of the human condition, the human experience, to see what can we learn from that extreme case and then apply. I was reading the chapter on slothfulness

yesterday and this idea that you put forward there about fatigue and, you know, being slothful is that kind of extreme case, isn't it? Where you're not going to do anything, you're tired, you sort of maybe come across as being lazy or whatever we might say about you. But you make this very compelling case that these things actually serve a role. They're there for a reason. Can you talk about that a little bit? Vivo Barefoot are one of the sponsors of today's show. Now, I am a huge fan of Vivo Barefoot shoes and have been wearing them for over a decade now, well before they started supporting this podcast. I've also been recommending them to patients for years because I've seen

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Yeah, you know, when it comes to to sloth, it can be defined in many different ways, but essentially, you know, our lives, an important function of humanity is to do things efficiently. You know, we don't want to be running around like headless chickens for no good reason. So what our brains are constantly doing subconsciously is asking one specific question, which is, is it worth it? Okay, is the energy that I'm going to expend in the pursuit of this reward, and you can interpret reward in a range of ways, is it worth expending that energy? And that obviously relies on a range of other things. It relies upon how you measure expenditure of energy. It relies upon how you measure reward, the size of that reward and the likelihood that you're going to get that reward. And it also then brings into

the frame emotions, because often our emotions define how we interpret reward. And that serves a really important evolutionary basis, because it would have been evolutionarily very bad for us to expend energy without getting anything for that energy expenditure. So obviously, that was when we were evolving in history. But it's still applicable today. So we want to try and preserve energy when we need it. A good example of that is when most people had COVID or had flu, that profound fatigue

that we all experienced when we were ill actually serves a really important role. In fact, there's a group of cells within our brains that actually mediate fatigue, that mediate all those changes in our behaviour when we have infection, with the ultimate goal of trying to divert energy that we would otherwise be expending to try and aid recuperation, to try and aid our immune system, to fight that infection, to try and aid recovery. So the body is creating fatigue for a reason. Exactly. Exactly. And so, you know, we all have, you know, as with Sloth, in fact, all the seven deadly sins and I use the term sins in inverted commas, these all have an evolutionary purpose

when they are present in the right situation, in the right context. It's when they are increased in intensity or inappropriate to that situation that they create problems. But Sloth, as with all the other sins, has a very important role in all of us. It reminds me a little bit of what Daniel Lieberman talks about in his book, Excercised, which is this idea that we haven't evolved to exercise. It's a very foreign and modern concept. You went to your hunter gatherer ancestors and tried to explain that you would literally go onto a treadmill and run 10 miles. And at the end of those 10 miles, you wouldn't

have actually got anywhere. You'd still be in the same spot. It'd be the most craziest thing in the world. Why would you waste all that energy, right? It's a similar kind of theme, right? It's exactly the same. So, you know, similarly, you know, when it comes to our drive to eat, you know, of course, from an evolutionary perspective, it makes total sense to eat when calories are available. You know, because what you want to do is you want to, particularly in a calorie poor environment, you want to take advantage of any calories that are available to you. In modern society, where those evolutionary imperatives are lessened because of the environment that we inhabit, that has resulted in really quite poor health consequences.

It's absolutely fascinating because the link was between sleep, of course, and sloth. You know, when you haven't got enough sleep, you're tired, right? So are you physically tired? Are you mentally tired, right? So are you physically tired? Are you mentally tired? I mean, after reading that chapter, it's quite clear that fatigue, we don't really fully understand fatigue, where fatigue comes from.

It reminded me a little bit of, if you had a professor, Tim Noakes, the exercise scientist, and he came with, I think, the central governor theory many years ago about this idea that the brain creates the fatigue. Let's say you're in an endurance race and you think you're tired. Well, it's not that necessarily you've run out of energy in your body and your muscles. The brain might be creating that for a particular reason.

And that is, you know, we can actually intervene with that. So for example, when it comes to physical fatigue, you know, people always assume, oh, it's the muscles that are telling us, oh, we've exerted ourselves a lot, therefore the muscles are tired. But actually, you know, the evidence points to physical fatigue as well as cognitive fatigue and mental fatigue and all these other types of fatigue as originating from the brain. If you give somebody a zap of a strong magnetic field over a particular part of their brain, which is the bit of the brain that communicates between the movement part of the brain and the sensation part of the brain, you can actually dramatically reduce fatigue because those

signals are not coming from our muscles, they're coming from our brains themselves. What about this idea that you could feel tired and put on one of your favourite upbeat tracks of music and in three minutes you can feel completely different and be dancing around your kitchen. Yeah. Right? What's changed? Well, I talked a little bit about the emotional inputs to our measurement of exertion. And there are important emotional factors that drive these mechanisms that ask that

question, is it worth it? So you can see that, for example, in certain specific examples of what's termed hysterical power. So these are individuals who perform some amazing feats of strength when their life is threatened or the lives of their loved ones are threatened. You know, things that they would never in normal everyday life be able to do. Because it's really important from an emotional perspective when you are in significant fear or you are in a heightened state of anger for that equation about energy versus reward or energy versus the benefit to be swayed quite significantly when you're

at peril, when your loved ones are at peril. And so it's not at all surprising that if you manipulate your emotional state, that is going to swing the dial on where that balance about is it worth it is. Yeah. It's almost as if we've all got 20, 30, 40 percent or whatever it might be in reserve at all times. We just don't know. But when the situation is right, when the emotion is right, when the situation calls for it, the brain can switch it on. It was something we've got this energy or this superhuman power that you talk about. I mean, some of those cases were remarkable. Was it like, was it someone lifting up a truck?

Yeah, a young boy lifting up a car off a neighbor on whom the car had collapsed or a woman defending her children from a huge grizzly bear, for example. But there are lots of these kinds of examples. And we see, when we look at Olympic athletes who are listening to aggression-inducing music on the start line in order to fire themselves up, this is part and parcel of what people do. They manipulate their emotional state. What's the take home from that for us? So I think it's to to understand, first of all, that fatigue and other aspects of sloth have an underlying basis in the way that our brains are organised, that they serve a useful purpose for some individuals. But it's also about understanding that this is

not a question of morality, and I think that this extends throughout the whole book. This is not a question of lack of moral fibre or inadequacy or anything like that. That this is part and parcel of who we are as human beings. To connect what we're just saying about fatigue back to sleep for a minute, throughout this conversation we're talking or we have been talking about this idea that many of us are struggling with sleep these days. We're not getting enough sleep, whether that's because of chronic sleep deprivation or insomnia. And I'm trying to have that idea sit alongside this idea

that actually we've probably got a lot more energy within us than we think at any one moment in time. And it's our brain that sets the dial on our energy levels. It's asking the question, is it worth it? On the face of those two things could be opposing in the sense that it's one of the reasons that we're sleep deprived because we can override fatigue.

We can change our emotional state every evening by putting on Netflix or if we get a bit bored, let's say, I don't know, 200 years ago, no light in the evening, no stimulating documentaries and whatever it might be to watch. So you're going to feel tired because actually maybe there's a boredom, a tedium that sets in. whereas now you can actually bypass that. You can go to a new novelty with the new show or the new trailer. Do you know what I mean? It's almost as if that's working against us now

where we can override that natural fatigue and that's making us even more sleep deprived. I think there's a lot of truth in what you say. You know, essentially a new reward is going to be more fulfilling than an old reward. And we have so much novelty in our lives that, of course, you know, watching a new Netflix movie is going to shift the dial in terms of the decision making that we undertake. There is one other, I think, important thing to point out, which is that sleepiness and fatigue are, you know, rather distinct. There is an overlap there, but they are essentially two different

features. So sleepiness is the tendency to doze off or fall asleep. Fatigue is the asleep. Fatigue is the lack of energy or the easily diminishable energy to undertake cognitive or physical tasks. And importantly, fatigue is generally speaking not improved by sleep. So there is a big distinction between the tiredness that somebody who has a fatigue syndrome, be that in the context of a physical condition, a mental health condition, a whole range of things and somebody who is sleepy. So they're not the same entities. They may interact and a lot of people, for example, who have fatigue will sleep very poorly. But, and poor sleep will make their fatigue worse, but they're not the same thing. Okay, super interesting. In terms of practical things that people can do

to help improve their sleep, as I mentioned to you just before we started recording, I've spoken at length before to Professor Matthew Walker and Professor Russell Foster about sleep and circadian biology. One of the things that really interests me about you is that in contrast to Matthew and Russell, you see patients.

So it's not just research, it's like hands-on with patients who are really struggling, which is always interesting to me is what sort of experience that gives you and therefore the insights that you have to share. You write about the profound benefits of CBT-I. I think particularly for people with chronic insomnia, first of all, can you explain what CBT-I is, who it's useful for, and what the goal of a treatment like that is. Yeah. So CBTI is a technique, a non-drug-based technique, that aims to improve sleep quality and treat insomnia. It was originally designed by a colleague called Colin Espy,

who's the professor of psychology in Oxford now. And it's a structured program that aids people to retrain their brain to associate bed with sleep and to associate bed with a full night's sleep and getting deeper sleep. So it has a number of different components to it. Some of it is about relaxation at night. Some of it is about making sure that you associate your sleeping environment with nothing but bed. Other aspects of it are related to, for example, trying to increase the pressure on your brain to sleep at an appropriate time.

Essentially what all of this aims to do is to reduce the amount of time it takes you to get off to sleep, to increase the amount of time in bed that you are asleep, and to increase the depth, both objectively and importantly subjectively, the quality of your sleep. And it does so very successfully. We know that about 80 odd percent of individuals get a significant improvement from this non-drug-based treatment alone. It can be helpful for the

vast majority of people with chronic insomnia. It can also be helpful in terms of trying to get people off sleeping tablets if they've been on sleeping tablets for a prolonged period of time. And unlike sleeping tablets, which if you don't take them, actually your sleep will probably get worse than it was before for a short time anyway, but if you don't take the tablets, your sleep is going to return to baseline. With CBTI, it provides an opportunity for a long-term improvement in your sleep beyond simply the treatment protocol that you're doing. So CBTI has very much become the first line gold standard treatment for anybody with

chronic insomnia. Does it help people with chronic sleep deprivation? No, the only thing that helps people with chronic sleep deprivation, I mean it probably would but it's not required because what people with chronic sleep deprivation need is to, for somebody to say to them actually rather than spending you know five hours a night in bed you need to be spending seven hours a night in bed. If they did that, then they would have no problem sleeping seven hours. So they don't need it. It can make them more aware of some of the aspects of surrounding sleep behavior, but it's not necessary to treat people with chronic sleep deprivation.

But they can learn aspects of it, right? So one of the things that you write about is this idea that it's about reconditioning someone's associations, right? So if they associate their bedroom and their bed with being a place of not being able to sleep and frustration and anxiety, you go through a process of trying to reshape that. I think the take home, certainly the thing I've spoken to patients about many times over the years, this is the idea that the brain is an associative organ. It associates certain behaviors in certain environments. And I understand that some people can do these things and fall asleep, apparently with no

problem. If you are struggling with your sleep and you're routinely doing work emails on your laptop in bed, I think a take home without having to formally do CBTI is, oh, maybe I should maybe do the work emails in my kitchen or my office and make sure I'm not bringing that into the bedroom. That's absolutely correct. This morning I was seeing somebody who was spending

two or three hours a night awake in the middle of the night in bed. And I said to them, well, this is a problem for you because the more time you spend lying awake at night in bed, the stronger the association in your own mind between bed and being awake rather than bed and being asleep. And what a lot of people with insomnia do is they spend more time in bed as a sort of adaptation to try and give them more opportunity to sleep. Whereas actually that's quite counterintuitive because what you want to try and do is you're essentially trying to retrain the brain to associate bed with sleep and nothing else. Certainly not doing your emails or watching Netflix or whatever else it is you're doing

while you're awake in the night. You're trying to associate, build that very strong association between bed and sleep. And you know, this is part and parcel of what CBTI involves. Yeah. Stress and its relationship with sleep is quite interesting, isn't it? There's a case in the secret world of sleep where you write about CBTI. I think you talk about one of your patients, you've given her the name Claire in the book, but what was really interesting, my recollection of Claire is that she was in her early 50s. She had given it work for a few years to bring up her children and then she was returning

to work. There was stress, the pressure she was putting on herself in her 50s to prove herself. And then CBT really, really worked super well. And then she stopped doing it or stopped engaging with all the aspects and her sleep started to deteriorate. That was fascinating but what was really interesting to me is that she said to you that this is because it was a loss of discipline with a sleep program. You wrote that you were not so convinced and this is what you said and I underline it because I thought it was so interesting. I think this was part of her tendency to have incredibly high expectations of herself, to take responsibility for everything around her and her reluctance to accept that she

does not have control over everything in her life. Guy, I reckon there's going to be a lot of people listening right now who would have heard those words and thought, wow, that applies to me. So I wonder if you could use that as a way of talking about, you know, internal pressure, stress, expectations, and how that plays into our ability to sleep or certainly fall asleep. Yeah. So, you know, again, it comes down to this view that all

of us are a little bit different. And we know that how people, their cognitive processes around sleep are intimately tied into their personality. You know, if you are one of these individuals who likes to control every aspect of their lives, likes to be in control constantly. And obviously sleep is one of those areas that you can't actively control quite so easily as you can, you know, how long your runners gone on for or, you know, what you're doing at work. The Berlin wall gate, you can't go with the exact key and go, if the harder I push and

the quicker I turn it, it's going to open it. That ain't going to happen. The harder you push, the harder it pushes back. And so, you know, for individuals who are of that sort of mindset, actually, it can be very destabilizing when one realizes that this is not something that you can strongly, actively control. The other aspect to this is that, you know, we're very good at giving patients very clear cut advice. You must do this, you must do that, you must not do that. But of course, life is not like that. For most of us, we have a life that gets in the way of sleep.

And I'm not suggesting that we should view it in that sense. But, you know, no day is identical. But for some individuals who are very, very focused on their sleep and they're very focused on the rules surrounding sleep, if they don't achieve those rules, it can be very destabilizing and create anxiety surrounding sleep. And so it can have negative consequences. Now, many people are not like that, but some are. And I think that this again, illustrates the fact that,

different people need different solutions to their sleep. For me, I would say, yes, I'm particular on certain things like I won't have any caffeine afternoon. I know for me that makes a big difference. If I probably won't have it after 10 a.m. personally for me. I would say, you know, I love this idea of keystone habits. You know, what is that key habit each day that you're going to do that will naturally mean other habits start to take place, other positive ones that you want.

We can think about that in terms of, is there something we can do each morning, for example, that means we're naturally going to make better decisions throughout the day. For some people, that's a morning workout. They start to eat better. They do other, you know, positive actions in the day if they get that done. If we flip it and think about it in the evening, I think for me, one of the things that I realized a few years ago is really 60 to 90 minutes before bed, if I can switch off my laptop and no longer be mentally engaging with work, that seems to be a one-time decision that irrespective of what I do after that seems to have a pretty phenomenal domino effects for me.

You know, and again, if you think about it from in relation to what you've been talking about throughout this conversation, the more I say that to myself, sleep well, reinforce that belief that that's important for me, it does become that self fulfilling prophecy as well, right? Yeah, yeah. And I guess the key thing is, for Claire, I would imagine, I'm not saying that this is the case for Claire, but for somebody like Claire, it might be that they say to themselves, well, I need to switch off my laptop 90 minutes before I go to bed. And then one day an email comes through at, you know, eight, you know, 91 minutes before bed and they have to stay on the laptop for another 15 minutes.

The danger if you are of that particular personality type is as soon as you, you know, go from 90 minutes to 80 minutes before bed, then you get yourself in a panic because you've lost control. And, you know, but, but, you know, ultimately this is about working out what works for you, you know, as an individual. And again, comes back to this view that there is no one rule applicable for everyone. You started in sleep medicine about two decades ago. ago, the public awareness, not only the public, the medical professionals awareness about the importance of sleep has dramatically changed over the past two decades. Generally a good thing?

Undoubtedly, I think. Look, you know, when you and I were at medical school, I certainly didn't get any teaching at all about sleep. It was only when I did an intercalated degree that I even heard sleep mentioned within the same breath as medicine. And you know, a lot of people have, I think, suffered as a result of the medical profession generally being quite uninformed about sleep. Now that's changed tremendously. And I think that that's had a huge impact. I think that we, an increased understanding of sleep issues, how to address those sleep issues has resulted in a dramatic improvement in the quality of life for many, many individuals

and hopefully also in the long-term health of those individuals. Of course, you know, it does have its downsides, because I think that as people have become more focused on sleep, there has perhaps been a little bit more misunderstanding and misinformation about certain aspects of sleep, but I think overall, it's a very positive shift. Yeah. In terms of practical tips for people, I'm sure people may have heard some of these

before, but with all of your clinical experience, what would you say some of those top practical things for people to think about when it comes to improving their sleep, if their sleep needs improving. Yeah. So, look, I think the starting point should always be, what do I understand about my sleep, my sleep quality and my sleep requirement to try and work out whether or not you are one of these individuals who wants to sleep more but is unable to, because they can't drop off to sleep, or whether you're one of these individuals who can always

sleep when they want to, it's just that they're not getting quite enough of it. I think that should be the starting point. Or of course, you may have no sleep issues whatsoever. If you have no sleep issues whatsoever, I would suggest you go away and stick your finger in your ears and not listen to another word that I'm saying, because long may that last. Yeah. Yeah. If you are an individual who is desperate for more sleep, but is unable to get it because they can't fall asleep, then I think that's the time to go and speak to somebody, go and speak to your GP, see whether or not there's anything that can be done in order to try and fix your sleep issues. If you're somebody who knows you're not getting enough sleep for yourself, because you know

that you can drop off whenever you want, but you still feel sleepy during the day, then you should probably just give yourself a break and actually allow yourself a little bit more time in bed to try and get a little bit more sleep. How big an issue do you think caffeine is in the modern world? I think increasingly people are aware of the impact that caffeine has and the fact that it can hang around for a lot longer than we think it can, depending on how much you drink. I think that you know of course for some people for about 10% of people they're completely insensitive to the effects of caffeine when it comes to their sleep. You know we'll all have met

people who say well I can drink a double espresso before bed and it makes no difference to whether or not I can sleep. Do you think that's true? I think there are some people who have genetic variants that make them insensitive to the effects of caffeine. I think last time Matthew Walker came on this podcast from Recollection, he said to me that even if you think you can have a double espresso just before beds, in most cases, although you may be falling asleep, it looks as though when we measure your sleep, that it isn't quite the same depth.

So, I think that's the case for about 90% of individuals, that it has some impact on their sleep. But there are a small group of individuals in whom it doesn't seem to have that much of an effect. But, you know, certainly I think that by the time people have come to my clinic, they will invariably have cut out all caffeine. But I think that by the time people have come to my clinic, they will invariably have cut out all caffeine. But I think certainly if you are having intermittent problems with your sleep and you're drinking coffee after lunchtime, then for God's sake, just try cutting out caffeine after lunchtime. It's a no brainer really.

On the train down to London today, I was thinking about your work, Guy, and this idea that permeates a lot of your work that who we are, whether it's our thoughts, our emotions, our mood, whatever it might be, is a reflection of the state of our brain. And then by that token, you know, the sleep deprived brain is a very different brain to a non-sleep deprived brain. So we know that when you are sleep deprived, your creativity goes down, your empathy goes down, your appetite often goes up, you know, your mood can go down, all these kind of things happen. And so then if we superimpose those statistics that you shared before, that maybe up to 40% of us are not getting enough sleep for a variety of different reasons, and who we are as an individual is hugely influenced by the amount of sleep that we got or did not get.

And then you think about the modern world where many people would say, at least online, we're very divided. People are very reactive. They're taking offense to everything. They're sort of quite combative, it's hard to not make the case that, wait a minute, if we could get everyone sleeping well in society, okay? And there's a big smile on your face for those listening on audio when you heard that. If we could, we're the magic ones. You kind of think what might the implications be,

not just for our health, our happiness, social cohesion, like our ability to progress forward in harmony? It's quite profound, isn't it? So what you're saying is that sleep doctors can change the world. Exactly what I'm saying. I entirely agree with you on that. No. So in terms of its relative relationship to all of these factors, it's probably small.

But given that it's so common, it makes perfect sense that actually, look, you know, we may not change the world. We may not suddenly all think Kumbaya around a campfire. But I think you're a bit more optimistic than I am. But certainly, look, there is the power by optimizing sleep in wider society. There may be some significant benefits for wider society, not just the individual. Yeah. If sleep deprivation is that common, it's hard for me not to make that leap. Many of us know, maybe some of your patients don't know, but I sure as hell know that the world looks very different after a beautiful night's sleep

compared to a broken night's sleep. I mean, you feel different, your experience of the world is different, how you interact with people is different. The other wild thoughts experiments I had on the train down this morning was I was thinking about caffeine. And yes, caffeine hangs around a lot longer than many of us think, which is why for me, for example, I generally don't

drink coffee after 10 AM, but then I go to bed pretty early as well. I was thinking when we were kids, there were not this many coffee shops in society. What does the coffee shops on every corner of every town and village and every airport say about the state of society? And then my thought experiment was how many sleep problems we might have in society if caffeine didn't exist? Could caffeine be having a societal impact on a wider scale? Well, yes, so could alcohol, so could nicotine. You know, all of these substances, I guess the slight difference between caffeine and drugs like alcohol and nicotine and other recreational drugs is that it has some useful benefits

as well. Should we be consuming less caffeine generally? Well, I think that if you are having issues with your sleep and you're drinking caffeine late into the afternoon, the answer to that is probably yes. Since you started studying sleep medicine, have you modified your own caffeine intake? Well, I'm very well aware of the impact of caffeine on my sleep, and I tend not to consume any caffeine after lunch.

Because I know that if I have coffee after lunch, it may well have an impact on my nighttime sleep. Since COVID, many children now are being given their homework on screens in the evenings. What's your take on the potential implications of that? So I think that, you know, historically what we've always said is, well, the exposure to blue light in the evening, and a lot of gadgets are very rich in blue light, can result in insomnia. Actually, more recent work has suggested that the impact of blue light in the evenings is not directly relevant to the night ahead, although there are some other factors at

play, but actually regular exposure to blue light in the evenings can push your circadian rhythm back. It can cause what we term a delayed sleep phase, so it can make you want to go to bed later and wake up later. And so, you know, particularly for young kids and especially teenagers who have a tendency to want to go to bed late and wake up late anyway, that kind of change in their circadian rhythm is part and parcel of development. Regular blue light late in the evening can actually accentuate that. And so it can have some really negative consequences because you imagine that if you're a teenager and you're

having to get up at 6.30 or 7 a.mam where your body clock is telling you actually I want to be getting up at 9 or 10 and you can't sleep until late into the night because your circadian rhythm has shifted, then you're going to end up very sleep deprived with the resultant consequences. Yeah, I mean I do have concerns over homework on screens in the evening for a variety of reasons, one of them being the impact on circadian biology. And I, again, I'm not blaming teachers. I think teachers are all trying to do the best that they can. But I think there are some real unintended consequences of giving large volumes of homework to children in the evening on screens.

But I think there's a second aspect to that, which is those screens can also be used for other reasons. And if you are inducing children to be on some sort of electronic gadget late into the night, then it's not just the homework that they're doing. It's also, you know, watching Netflix or, or, you know, on social media, none of which is particularly conducive to sleep. Yeah. And the truth is how many adults have gone onto their laptop to do one thing and just did that one thing. I think many have struggled to modulate that. So yeah, something to, I want to keep talking about on this podcast to raise awareness. Many teachers listen. It's just a case of, hey, maybe we need to think about other ways or, maybe not giving a screen for homework in the evenings.

about other ways or, you know, maybe not giving a screen for homework in the evenings. Okay, so Guy, I had a question for you to do with me. And I've got a few ideas, but given you are such a renowned sleep expert, I thought I'd put it to you. Okay, so... I'm feeling the pressure now. Feeling the pressure, okay, all right. My current body clock is set up something like this, okay? So I will usually be asleep by 8.30, 8.45 p.m., okay? Pretty early. And I'm usually awake by 4.30 to 5.00 AM. Okay, now my life is great when I'm sort of like that and I have the regularity around that

for a variety of reasons. I love going to bed early, I love waking up early and having that time to myself in the morning before the rest of my family gets up. In March of this year, I'm doing a national theatre tour around the UK. It's every weekend for five weekends. I'm not doing it all in one go because I don't want to be away from my family that much, but I'll be coming home in the week. But I'm going to be on

stage in front of a couple of thousand people each night, probably between 7.30 PM and I would guess 9.30, 9.45 PM, I'm not going to suddenly finish and be nicely relaxed and ready for bed. So a theoretical question, I know you usually see sleep disorders, so I don't have an issue with sleeping, but I, over the next few weeks, I'm going to try and shift my circadian rhythm to make

it more amenable to when I'm on tour. So far so good? Yeah. Okay. So, what sorts of things would you recommend I think about doing in the lead up to my tour? Because this kind of circadian rhythm is not going to be that sustainable for me when I'm on the road. Yeah. So there are a number of different factors that influence our circadian clock. And they're

given the German term Zeitgeist, time givers. The most potent of these are melatonin and light, you know, because essentially our circadian rhythm is largely in nature governed by the sun. Essentially, what you are wanting to do is you're trying to delay your circadian rhythm. You have something called an advanced sleep phase. So you are, you know, you're a morning lark, but you're also in bed very early as well. And so what you are aiming to achieve is for this period of time is to delay your sleep phase. You're trying to push it back. A bit like going to a new time zone.

You're trying to correct jet lag for a little while. Now, when it comes to giving people melatonin, it can be rather difficult because melatonin, the timing of when you take melatonin according to your own internal body clock can make the shift in your circadian rhythm vastly different. And so essentially what you want to be trying to do in order to delay your sleep phase is take melatonin in the morning, which is generally not a good idea because it can sedate you a little bit. But one of the things that you could consider doing is actually trying to delay your sleep phase

by exposing yourself to bright light in the evenings. In the same way as, you know, your concerns about children doing homework on gadgets. What you're trying to do is you're trying to push your circadian rhythm back in the same way as you're definitely not trying to do to your kids. And so actually using something like a sun lamp or there are some glasses that you can use that generate really quite intense light that simulates sunlight in the evenings would probably be the single most useful thing you could do to delay your sleep phase a little for the duration of your book tour. Okay, so would and let's say I'm starting on the 1st of March, which is something similar to what

I am doing. I can't remember the exact date. When would you recommend in February I start to go about that process? So there is a limit to how quickly our circadian clock can shift and it's usually about one hour per 24 hour cycle. So you know if you're trying to delay your sleep phase by two hours, I think two hours would be enough. Two hours. So probably within a week or so, you could probably shift it back a little bit with regular exposure to very bright light in the evenings. Okay. So bright light exposure in the evenings to help me push my circadian rhythm back, which is pretty much what I was planning on doing.

I was also going to try and delay my caffeine in the morning from the current time of like 530am, probably trying to push that. I mean, my hope would be that by having that bright light exposure in the evening, I'm going to fall asleep later and hopefully wake up later. So everything will start to shift. Anything else you'd recommend? Yeah. So all the other activities. So we know that, as I said, melatonin and light are the strongest psych abers. But we know that when we exercise, when we eat, when we drink, when we open our bowels, all of these aspects do have subtle influences on our circadian rhythm. So really trying to think about not just shifting your wake-up time, not just shifting your caffeine, but also shifting when you exercise, when you eat for that period of time is all going to help a little.

Yeah, for example, I know that any form of moderate to intense exercise done after 5 p.m. plays havoc with my sleep currently, because I can't down regulate enough in time for bedtime. But you can flip that and use it absolutely for my favor, you know, at 5 p.m. before I'm on that evening. I could do an intense workout, for example, which is also going to help me not fall a seat for some time. And again, I'm bringing this up because I think it's relevant to people who maybe do shift work, for example. Although I'll be back home Monday to Thursday on those five weeks, I'm not planning to shift back to 8.30 PM, sleep time, 4.30 AM, wait time.

My goal would be to try and shift that and keep it for the entirety of March. Well, I think that's very wise because I think trying to shift back and forward for a couple of days is actually quite a big ask. Yeah. So I think if you're going to do it, you should try and do it for that whole month. Yeah. Well, that'd be a fun experiment and see what happens. You'll have to let me know. Yeah, I will. I'll let you know how that goes. Okay, Guy, listen, there's so much stuff in your books that we could talk about. Like, it's really interesting for me to observe how you write and what you write about. And these seemingly disparate topics are actually quite beautifully connected.

It's the human experience, right? It's how our biology impacts our behaviors on so many different levels. What would you say is the kind of common theme that sits together throughout all of your books? So, you know, what I've tried to do throughout my books is to relate how this lump of fatty tissue, which is the object of fascination for neurologists and neuroscientists, really defines every aspect of our being. It defines how we behave, how we experience the world, how we understand it, how we move through it, how we sleep through it.

You know, all of this originates within the brain itself. And through looking through what happens when it goes wrong, it also tells us how it works when it goes right as well. Yeah, I love that. And for someone, Guy, who's listened to our conversation, who does struggle with sleep, and he thinks actually, you know what? I need to do something about this.

What would you say to them? Well, I think the first thing to do is to educate yourself a little, because as we already discussed, the understanding amongst the medical profession is highly variable when it comes to sleep. I'm really pleased to have noted a massive shift in terms of how much doctors know about sleep. So I think the starting point should be educating yourself, but also going to speak to your GP.

Yeah, okay. Well, Guy, thank you for all the wonderful work you do treating patients in your clinic, writing these wonderful books, and that's coming on the show. Thanks a lot for having me. Really hope you enjoyed that conversation. Do think about one thing that you can take away and apply into your own life. And also have a think about one thing that you can take away and apply into your own life. And also have a think about one thing from this conversation that you can teach to somebody else. Remember when you teach someone, it not only helps them, it also helps you learn and retain the information. Now before you go, just wanted to let you know about Friday 5.

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