The Sleep Doctor: Why You Feel Tired All the Time (Even If You Sleep 8 Hours) — Dr. Guy Leschziner

0:00We are told that we should be sleeping between 7 and 8 and a half hours. That's the sort of sweet spot, but it's much more complicated than that. Dr. Guy Leschner is a professor at King's College London and a world-leading consultant neurologist who previously led one of Europe's largest sleep units for over a decade. He also runs specialist sleep disorder and epilepsy clinics across the UK and is an established author. Why do we dream? And when does dreaming occur? Are there any studies that confirm that the keto diet can help you sleep better? Whenever you talk about significant dietary manipulation, you need to look at...

0:35I've heard many times the phrase, I need to sleep on it. Before you go to sleep, you have these worries. You wake up and magically, they're not totally gone, but they are toned down, watered down. Is this because the emotional side of our brain gets reset? So it's termed by some researchers as overnight therapy. Yeah. Small areas of our cerebral cortex are dipping into sleep right now while we're talking. Lucid dreaming is a normal phenomenon. In fact, there are some people who say that they've trained themselves to lucid dream. Can you? The typical phenomenon that I see quite regularly that is perhaps most applicable to the people listening or watching this is...

1:21What is modern society doing to our sleep? I think there are a number of potential factors. So the first is...

1:35Dr. Guy, good morning. Morning. At your request, I'm going to call you Guy. Yeah. So you are a well-reputed neurologist, which specializes in sleeping disorders. can you please share with me what are your credentials that allow you to speak as an expert in this subject matter? Yeah, so I for the last decade or so until recently headed up the sleep disorder centre at Guy's Hospital which is one of the largest sleep disorder centres in the UK. My background is I trained in general neurology, did a PhD in genetics and epilepsy and then very early on in my training I started being exposed to individuals with sleep disorders.

2:18I was very lucky in that one of my predecessors had come back from the United States in the early 90s and had been one of the first people to really specialise in sleep medicine and so for the last almost 20 years or so I've been seeing individuals with sleep disorders. I've written textbooks, I've published widely in the sleep world. I've written a book called The Nocturnal Brain, which is trying to explain sleep disorders for lay individuals, detailing some of the weird and wonderful cases that I've seen over the years. And so I'm still very much immersed in the world of sleep medicine and have been for decades.

2:58Interesting. Why did you dive into sleeping disorders? because if I basically take a law analogy, you study law, it's a general practice, and then I'm assuming that you specialize in a particular practice. If you study neurology, you could have gone into so many different other streams. Why sleeping? So I think the first thing to say is I still do other stuff as well. So I do general neurology. I also run weekly epilepsy clinics. You know, epilepsy and sleep disorders sit very comfortably together. for a number of reasons. The first is that the same tools, the same technology is used to study the brain from an epilepsy perspective as it's used in sleep disorders.

3:44The second is that when it comes to individuals with sleep disorders, a lot of the time what we're asking is, why is this person doing odd things at night? Could it be epilepsy? Could it be something else? And finally, of course, sleep disorders affect every aspect of neurology, not just actually more broadly, every aspect of our physical health, but particularly across all other neurological specialties when it comes to headache, when it comes to seizures, when it comes to neurodegenerative disease. And so sleep and the study of it is applicable to every aspect of neurology. I was kind of fortunate because as well as being in a hospital when I was training, whereby somebody had some sleep expertise.

4:31When we went through medical school, and until very recently, actually, this was the case, there was no teaching whatsoever on sleep disorder. Sleep didn't figure on the curriculum at all. But I did something called an intercalated degree. So when you study medicine in the UK, a lot of people do an additional year in order to take a degree in a particular area. And I did a intercalated degree in neuroscience. And I remember very distinctly, one of the first bits of work that we were asked to do was to research and write an essay on why we dream. And until that point, you know, actually, I'd given very little thought to sleep, but I became fascinated by really how little was known about sleep, yet we do this eight hours a day.

5:18And that was really the first bit of a carrot in order to make me explore sleep a little bit more widely. So this means that it is safe to say that you're one of the pioneering researchers in this area? Well, I think I'm certainly one of the individuals in the UK and in the world who sees the most patients with sleep issues, and I do some research on the side. Interesting. I have a lot of friends that they suffer from sleeping disorders. At least they think they do. They self-diagnose themselves. I think this is something that is happening more frequently in this day and age. and I've always wondered because some of these friends they have fairly similar backgrounds they're from the same country and they work in similar jobs I would assume they have similar stress levels so I was wondering what are the main root causes for sleep disorders are they mostly genetics based lifestyle based so basically nurture versus nature yeah I think all of that is applicable.

6:28So we know that a lot of what defines how we sleep is genetic. So when it comes to the timings at which we sleep, when it comes to our sleep requirement, when it comes to certain sleep disorders, but also undoubtedly there is a very strong environmental influence. So, you know, when we talk about how modern society has changed and the fact that there are certain aspects of modern society that I think are quite conducive to insomnia when it comes to weight gain, which is a really important issue when it comes to conditions like obstructive sleep apnea. And we also know that there is a very strong interaction between genetics and environment.

7:14So for example, when it comes to certain neurological disorders, like there's a condition called restless leg syndrome, we know that that often runs in families, but it's also affected by our kidney function, whether we're pregnant, what our iron levels are like. So it's a case of a cumulative effect that achieves a particular threshold to developing the symptoms of a particular condition. Let's take the case of modern society. So I've read in one of your studies that most tribes in Africa or in Latin America, they barely suffer from insomnia. What is modern society doing to our sleep? I think there are a number of potential factors.

7:59So the first is, look, we don't live in a pre-industrial society anymore. We have light at times where light would not normally be available. And I think that the influence of light on our circadian rhythms is very well understood. Can you please explain to us? So our circadian rhythm is our internal body clock. And it defines what time we start to feel sleepy, what time we drift off to sleep, what time we wake up, but also other aspects of our health. So what time we want to eat, what time we want to open our bowels, you know, when we feel most cognitively impaired or unimpaired. And so this biological clock is focused on a very small part of the brain called the suprachiasmatic nucleus that's the master clock that influences all the other clocks in our body and you know all our organs have their own clocks but they are coordinated by this master clock and light is a very important factor in terms of defining our circadian rhythm our internal clock so for example if we expose ourselves to bright lights in the evening particularly light that is rich in the blue part of the spectrum, then that can fundamentally shift our internal clock back, making it more difficult for us to go to sleep and wanting to go to sleep later and waking up later.

9:23And now, of course, in modern society, that is made much worse by the fact that we're often using gadgets in the bedroom late at night, we're on our laptops, we're on our tablets, on our phones, which all produce blue light and can result in that, what we term a phase shift, a shift in the in the body clock. So that's one, you know, very good example. The other issues are surrounding what we spend our lives doing. So our lives are much more fast paced. They're probably stressful in a very different way. Look, life has always been stressful. And it would be idiotic to say that, you know, 200 years ago, life was not stressful for individuals.

10:01But the fact is that, you know, we barely switch off these days during the day. And that undoubtedly has some psychological effects on our levels of what we would term arousal. So levels of how excited we are, how much adrenaline is circulating in our systems, which also has an important effect on our ability to sleep. And then there are a number of different factors. So I've already talked about weight gain. We live in an obesogenic society. We as a society in Western countries are putting on weight, and that has fundamental impact on the quality of our sleep. There's also the fact that probably now we, as a wealthier society, more of us are drinking more regularly alcohol.

10:44I know that there have been some shifts recently, but we know that everything that we put in our bodies can also affect our sleep as well. So if I were to summarize this, the blue light levels have increased, stress levels have increased and also obesity levels. So is it safe to assume that if I shift the direction of my life towards utilizing less technology, i.e. meaning getting less blue light, reducing my levels of stress, so perhaps having less stimuli around me, like switching off my phone at specific time frames and so on, not being as committed socially, and then having a healthy diet, would these three things go a long way towards improving my sleep?

11:28Potentially, yes. So it's important to say that there is no one solution that works for everyone. You may be one of those individuals who can sleep regardless of how much stress you've got in your life, regardless of how much TV you're watching in bed or how many emails you're answering in bed. And for individuals like that, who we describe as having low sleep reactivity, so reactivity is a psychological phenomenon that means that your sleep is more liable to disruption by external factors. Some people have got very low sleep reactivity and can sleep like a baby regardless of what's going on in their lives, regardless of how much coffee they've drunk, regardless of how much stress they've got.

12:09But if you are one of those individuals who has high sleep reactivity, so you know that these factors influence the quality of your sleep, then obviously by changing those factors in your life, then that is likely to result in a net improvement in your overnight sleep. And how can you identify as an individual, which of these factors is the one affecting you? So I think the first question to ask yourself is, am I sleeping well? You know, am I able to sleep when I want to? Am I able to wake up when I want to? Am I waking up feeling refreshed? And am I able to stay awake during the day and feel like I'm functioning well?

12:47Is that the definition of a good sleep? Yeah. So I think that there is, in part this is driven by the fact that we are metricizing our lives we're measuring everything and we're using sleep trackers and we're using in particular using sleep trackers to try and measure our sleep and get some measure of how refreshed we are but ultimately you know sleep is a subjective experience and the other thing to say is that everybody is different so we focus on the fact that we are told that we should be sleeping between seven and eight and a half hours. That's the sort of sweet spot for sleep duration. But it's much more complicated than that.

13:28You know, coming back to your comments on genetics, we know that our genetics have a very strong influence on how much sleep we actually need. So there are some families that I've seen who only sleep four hours a night and don't require any more than that. They function entirely normally and that's been linked recently to one particular gene. Now that's quite a rare gene and the fact is that probably if you are sleeping four hours a night that's much too short for you unless you are one of these few and far between individuals who carry that gene. So we know that our genetics is important but it's also a function of what age we're at because our sleep requirement changes throughout our lives.

14:11You know, we need much more sleep when we're children. We still need quite a lot of sleep when we're adolescents. And then as we get older, our sleep requirement drops. But it's also a function of the quality of our sleep. So do we have a sleep disorder? Is our sleep being disrupted by something? And so all of these factors define how much sleep we need. And so rather than fixating, and yes, seven to eight and a half hours is what the average person needs but you can fall outside of that margin and still be normal and I guess the real question is whether or not you are going to bed at the same time roughly every day you're waking up at the same time roughly every day when you want to sleep you can when you wake up you feel refreshed and that you're able to stay awake without difficulties during the day let's take the example of my girlfriend so I would according to your methodology to assess on whether a person sleeps good or bad I would say she's not a good sleeper she can't go to sleep very quickly takes her a long time and she wakes up multiple times and at night I think sometimes it's related to her breathing because she can't breathe efficiently from her nose but there may be other other issues so for someone like her like she wakes up and she's sometimes tired and when she goes to bed sometimes she dreads the already envisioning her bed, which for me is the opposite.

15:42I feel as my bed is this comfort, safe space for me to feel refreshed. But she has a completely different definition or understanding of what her bed represents. How can she individually, without seeking professional advice, identify what is impacting her sleep? Yeah, so, I mean, it's always difficult to do a virtual consultation without the patient in the room. But it sounds to me like that she has developed some negative associations between bed and sleep. And this is a very common issue for individuals who have a tendency towards insomnia. So what we understand in insomnia occurs is that there are some psychological changes that influence that association between bed and sleep and what should be a positive association as it is in your case is replaced by a negative association so sleep becomes a or the bedroom becomes a place of stress a place of frustration a place of irritation and that and now some of that is very easy to determine because we are aware of those associations but we also know that what is important in insomnia is some unconscious associations as well.

17:01So you may recall from your school days, the story of Pavlov and his dogs. So Pavlov was a famous neuroscientist who trained his dogs to associate a bell ringing. Conditioning. Yeah, it's a conditioned response. And we also exhibit lots of conditioned responses. So we may not be that hungry and we come into a restaurant and we see a beautifully laid out table and we start to feel hungry because we associate what we're seeing, what's in our environment with eating so i feel responsible now because i'm part of of the bed equation with her so if she's dreading it i'm part of well you're you are associated with negative outcomes clearly um the the uh and and so it becomes a bit of a self-fulfilling prophecy so if your brain already expects the fact that when you go into the environment the bedroom for her the bedroom the furniture in the bedroom, the duvet, everything within that room is associated with difficulty sleeping rather than going to sleep.

18:02And so a lot of the focus on insomnia is about trying to break that negative association, rebuild positive associations. Now, of course, it may be possible that she has some problem with her breathing at night, but I don't think that would be likely to cause her difficulty getting off to sleep in the first instance. Sometimes sleep apnea or other forms of sleep disorder breathing can coexist with insomnia.

18:36What is sleep apnea? So obstructive sleep apnea is a condition whereby when we go off to sleep, all our muscles relax, particularly in dreaming sleep, in REM sleep, our muscles really completely lose any tone or tension. And there are lots of muscles that sit at the back of our throat in our airway. And when we are asleep, and sometimes this is worse when we're flat on our back, the airway becomes a little bit narrowed. It becomes a little bit less rigid, more floppy. And so when we take a deep breath in, the airway walls vibrate and that's responsible for snoring. But sometimes if the airway is narrow enough or is being compressed in some way, then it can collapse down and partially or completely obstruct.

19:22And what happens with those obstructive events is that the brain then says, oh, something is going wrong here. My oxygen levels are dropping. I'm having difficulty breathing. And you partially wake up. And actually, for most people, they're not aware of those brief awakenings or arousals and as you wake up then the airway the tension returns to the muscles the airway opens again and you start breathing again and sometimes that pattern can persist throughout the night that can give rise if you think about it to disruption of your sleep you know 10 sometimes even up to 100 times an hour and so can result in difficulty staying asleep at night but also feeling very exhausted and sleepy during the day interesting so the problem is in the throat.

20:04So the problem is a biological issue, a structural issue in the back of the throat that is actually very common. And, you know, we associate obstructive sleep apnea with people who have put on significant weight, but we know that there are plenty of people out there who are very thin and because of the shape of their airway, and this comes back to genetics again, because our genetics influences our facial anatomy, our throat anatomy can give rise to obstructive sleep apnea as well. I feel like we live in a day and age in which we love to self-diagnose ourselves. And right now, I think with AI, with tools like ChatGPT is becoming even more exaggerated.

20:44Yeah. When would you say is the right moment to seek professional advice? Well, I think that if you think that you may have a condition that is caused by a biological problem, that's the time to seek advice. If you have tried basic things so you think that you've got insomnia and you've tried very basic things to try and help yourself and that's not worked that's the time to seek advice. Now it's complicated by the fact because when we started I said well you know as medical students we had no education on sleep disorders at all and I think that the level of knowledge amongst the medical profession about sleep disorders is highly variable.

21:26It's getting a lot better. And I think that most GPs, particularly in this country, do have an understanding of sleep disorders. So I think that if you've tried some basic interventions and it hasn't helped and you're suffering during the day, then I think the first port of call is not to consult ChatGPT, but to go and see your doctor. Okay. In one of your studies, you mentioned that different parts of the brain sleep or rest at different moments. Can you explain further? Well, I think you and I, while we're sitting here, there is good evidence that actually small areas of our cerebral cortex are dipping into sleep.

22:16Right now. Right now, while we're talking. So there is this concept of what we term local sleep, that our cerebral cortex, which is the outer lining of our brains, constantly has little islands of sleep. And those islands get more spread, and the periods of sleep get longer the more sleep-deprived, the more tired we are. And it's likely that that is responsible for why, when we're particularly sleep-deprived, when we are tired, our cognitive function deteriorates. So there is this concept of local sleep whilst we're awake but there's also this concept of local sleep whilst we're asleep so that rather than the brain sleeping as an entirety that different areas of the brain can exist in different stages of sleep or wake simultaneously and we know that this happens for example in sleepwalking so in individuals who are doing really quite complex things at night arising from very deep sleep that actually if we study their brains either electrically or using scanning techniques that measure metabolic activity that whilst certain areas of their brain remain in very deep sleep other areas of the brain seem to enter into a waking state and when you look at the pattern of those changes it correlates very nicely with what people are doing so in sleepwalking for example the areas of the brain that seem to demonstrate waking behavior are the areas of the brain responsible for movement and for vision and also for emotion which is why a lot of sleepwalking events or confusion or arousals are associated with strong emotional content and that's what night terrors are.

24:07Whereas the parts of the brain that exhibit ongoing, very deep sleep are areas of the brain called the hippocampus, which is responsible for memory, which is why a lot of people don't remember these events. But also importantly, an area of the brain called the frontal lobes. And the frontal lobes are where we do our rational thinking, our planning, our reasoning, which is why we're perhaps doing inappropriate things at night during these events. But even beyond sleepwalking, we know that a lot of the experiences that many normal individuals have are related to the fact that we don't sleep with the whole of our brain all the time.

24:43So when it comes to things like sleep paralysis, which is a normal phenomenon, it's something that about a third of students will experience, where occasionally when you wake up, you feel wide awake, but you feel completely paralyzed for a few moments. Or what we term hypnagogic hallucinations so sometimes people as they drift off to sleep or wake up will see things or hear things in the room these are all as a result of the fact that actually our brains are existing in different stages of sleep simultaneously going particularly discussing particularly about sleepwalkers um so we now have an understanding of what's happening different parts of their brain are sleeping but some other parts are awake in particular our motor skills division and they are fueled or sourced by strong emotional charges does this mean that perhaps our limbic system is also awake yeah so the the limbic system is this this area of the brain that is often responsible for emotional processing and we see increased activity within the the limbic system during particularly sleepwalking events that have a very strong emotional narrative to them.

26:01I mean, this issue of being in different stages of sleep or wake at the same time actually is really important in another context. We talked to, I mentioned before that sleep is a subjective experience. One of the situations that we often find is that with people with insomnia who say, well, look, I sleep really badly. I get very little sleep at night. When we actually measure their sleep, what we see is they're actually sleeping pretty well. They are not necessarily sleeping that much less than an individual who doesn't complain of insomnia. And we used to think of that, and that's termed paradoxical insomnia.

26:41So it does affect some people, although most people with insomnia will have a degree of discordance between objective measures of sleep and subjective measures of sleep. It used to be thought of that that was entirely a psychological phenomenon, but actually there is some preliminary data to suggest that that too, that experience of being awake when you're actually asleep, is actually related to the fact that there are areas of the brain that are responsible for awareness or consciousness that don't enter into as deep sleep as the rest of the brain. And so whilst you are sleeping, that bit of the brain that's responsible for being aware of what's going on, or at least understanding the passage of time, may not be entering into such deep sleep.

27:24Is it meaningful in a way what we do when we are sleepwalking? So is that telling you something about that person's personality? I don't think so. Look, this is very much a neurological disorder. It doesn't necessarily tell you much about somebody's psychological status or their underlying personality. Essentially, you know, the way to think about what we do in sleepwalking is that this is a result of a dysfunctional brain at that moment. So in the same way as people doing very odd things when they have very low blood sugars. So, for example, if you're diabetic and you inject yourself with too much insulin, or if you've had a major head injury, or if you have just had a seizure, all of these represent either a transient or a permanent state where your brain is not working properly.

28:22And that's the same in sleepwalking. Now, that's not to say that your psychological status may not influence whether or not you are having these events, because we know that if people are highly anxious or depressed or have other mental health issues, their sleep is going to be a bit more broken. And that's going to influence the likelihood of you having sleepwalking events. It may also influence the content of those. So, for example, we see people who get up at night and eat in their sleep, something called sleep-related eating disorder. And we know that that seems to arise more frequently in individuals who have eating disorders during the day.

29:03But as a general rule, if you are a sleepwalker and you're doing very odd things at night, that does not generally give you any illustration as to your underlying character or personality or moral value. you said that sleepwalker has a disorder for me when i hear the word disorder there's like a red light red flag in my head that just pops up and i immediately want to solve it so if for example i see that my partner is a sleepwalker is that a sign for me to seek help because that needs to be solved well i think that that look lots of people sleepwalk for lots of people that's not a problem. So the issue is, are you putting yourself at risk?

29:49Are you putting somebody else at risk by sleepwalking? Is it particularly embarrassing? Is it affecting how you feel during the day? And, you know, if none of those apply, then you may prefer just to say, well, look, I'm just going to try and improve my sleep a little bit and see what the impact is. But I think particularly if you're putting yourself or somebody else at risk, it's definitely worth trying to solve it. What about sleep talking? So sleep talking is essentially a very mild version of sleepwalking. So we know that sleep talking often arises from those deep stages of sleep and is, you know, it's pretty common.

30:27There are other situations in which people can talk in their sleep. So one of the areas that is a very hot topic at the moment is a condition called REM sleep behavior disorder. So unlike sleepwalking and classic sleep talking, which arise from deep non-REM sleep, REM sleep behavior disorder, as the name suggests, arises from REM sleep, from dreaming sleep. And normally we're completely paralyzed in dreaming sleep. The only muscles that work are the muscles that control our eyes and the muscles that allow us to breathe for obvious reasons. But in some individuals, that mechanism of paralysis which is part and parcel of normal REM sleep, doesn't work properly.

31:10And so people will sometimes act out their dreams. And so sleep talking or sleep shouting can occur in REM sleep behaviour disorder. Now the reason why that's important is because REM sleep behaviour disorder is associated with what's termed the prodrome, the precursor to some neurodegenerative disorders. And particularly if it starts late on in life, if it may be an indication that there might be a degenerative process going on in the brain. Can you please describe to me the difference in between REM sleep and non-REM sleep? And when do they occur? So if we look at it from on the sort of macro level, we divide sleep into REM sleep and non-REM sleep.

31:54Non-REM sleep... So those are the two stages of our sleep. Well, we then subdivide non-REM into other divisions. divisions, but those are the two major stages. Non-REM sleep, when we study it electrically, when we study it metabolically, we see that the brain slows down. So for example, when we have electrodes attached to the scalp, in wakefulness, we have very small, very high frequency rhythms. As we drift into the deeper stages of non-REM sleep, we see the electrical activity slowing down, those waves reduce in frequency, they become more synchronized. And essentially, this is the brain quietening down.

32:40Whereas REM sleep is very different. If we look at the, and what is happening within the brain in REM sleep, it actually looks remarkably like wake. So the rhythms speed up again, they become smaller amplitude, our muscles become paralyzed. So it's almost like we are awake but cut off from the external world and so we cycle between non-REM and REM sleep roughly four or five times a night about once every 90 minutes and we as we progress through the night in the latter half of the night we have much more REM sleep than than we do in the in the first half of the night and when we look at the divisions of non-REM sleep in the first half the night we do a lot more of the deep non-REM sleep and in the latter half the night non-REM sleep often becomes lighter.

33:32So we would expect for most people to go into their first stage of REM sleep within about an hour to 90 minutes of dropping off to sleep and then to recur every 90 minutes or so. And when does dreaming occur? Well we used to describe REM sleep as dreaming sleep In fact, to some extent, we still do. But actually, we know that dreaming occurs both in REM and non-REM sleep. Typically, the dreams of a narrative structure, you know, those stories evolving in our minds, occur in REM sleep. But actually, in non-REM sleep, if people remember their dreams, they're often much more basic. They're often little vignettes.

34:10They often have a brief moment of emotion or a visual flash rather than these stories evolving. Why do we dream? Well, I think it's a very good question. I think that if we, as I've already said, I think we need to distinguish REM sleep from REM dreaming from non-REM dreaming. And so when we talk about why we dream, we're typically asking, well, what is the function of REM sleep? And the likelihood is that as with sleep in general, there is more than one function to these processes that go on within our bodies. There are a number of potential theories, and they remain theories. But we know that that cycle between non-REM and REM is important for memory consolidation, for learning.

35:06And so what we think is happening is that there is some reorganization going on in terms of information and how it's stored within the brain. It's also likely to be important for the regulation of our emotions. So in particular, there is a theory that says that one of the functions of REM sleep is to take our memories that are associated with strong emotions and to gradually reduce the emotional content of those memories. So it's termed by some researchers as overnight therapy. And there are some theories that are based upon observations in people with post-traumatic stress disorder, which is that a lot of people with post-traumatic stress disorder often have very recurrent nightmares that relate to their original trauma.

35:55But because they're waking up with the very strong emotional content of those nightmares, that process is never completed. And so the emotional cleansing that is required never occurs. my own um view is that one of the likely functions of REM sleep is that it REM sleep because we our brains are active but we're shut off from the outside world it's basically as if we're offline from from the environment but we're attending to our own brains and so that gives us a an opportunity to integrate the experiences that we've had over the last day over the last week and so on into how we understand the world.

36:38And there are some important issues surrounding that because we know that our brains, in terms of how we understand reality, are working as prediction machines. So it's not simply the case that we, you know, our brain reconstructs our environment based upon what we see, what we hear, what we experience on a minute-by-minute basis. And actually what our brain is constantly doing is taking information from our eyes and ears and all our other sensors and is saying, does this meet with my expectation of the world, how I understand the world to work? And it's when there is discordance between what our sensors are telling us and what we expect that we then adjust our expectation of the world.

37:20And that's really a shortcut because we don't have the data power, we don't have the bandwidth to recreate our world on a second-by-second basis. and so we need an internal model of how we expect the world to appear to sound to function and that adjustment depending on what we've learned is probably happening during REM sleep is safe to say at least i've always assumed this throughout my life and maybe i was wrong all along but is it safe to say that if i dreamed last night i had a good night's sleep um no not at all so almost 30 years so um the the experience of dreaming is typically associated with waking from REM sleep and so there are some individuals who kind of wake from REM sleep and feel very refreshed it doesn't particularly signify anything but there are some individuals who actually dream very vividly every night and they find that incredibly disrupting to their sleep they wake up feeling completely unrefreshed and it may indicate that actually something is disrupting your REM sleep so there's no real correlation between whether or not you remember your dream and how good quality your sleep was and what about lucid dreams dreams in which you are aware that you're dreaming is that real yeah absolutely so um lucid dreaming is a normal phenomenon okay so so you don't need to have a disorder in order to lucid dream and in fact there are some people who say that they've trained themselves to lucid dream can you there are some things that can be done to try and enable you to lucid dream now it used to be thought of as a bit of pseudoscience but actually there have been some remarkable studies done which demonstrate that lucid dreaming is a very real phenomenon.

39:19So there was a famous study done a few years ago in Germany whereby they got lucid dreamers into something called a functional MRI scanner. And they asked them to, in that scanner, to lie awake and to clench their left hand and then clench their right hand and alternate. And what they could see was that the areas of the brain that were involved in generating those motor functions lit up. They then got them to lie in the scanner while still awake and asked them to imagine that they were clenching their left and right hand. And again, they showed similar patterns of activation. But these individuals were all lucid dreamers.

39:55And they asked them to go into the scanner and they monitored their sleep. And when they were in REM sleep, they said, well, you know, you're a lucid dreamer. I want you to, in your dream, imagine that you're clenching your left hand and then clenching your right hand and alternating. And sure enough, they showed that similar areas of the brain were activated. So very clearly demonstrating that this has a basis in reality, a basis in neuroscience. The thinking parts like the frontal lobes? The parts of the brain that are responsible for generating movement. So lucid dreaming is a very real phenomenon.

40:27It also occurs in individuals with certain neurological disorders like narcolepsy. So narcolepsy is a relatively rare disorder that results from an immune attack on a particular part of the brain that regulates dreaming sleep. And so individuals with narcolepsy, they often are very excessively sleepy during the day and they have some other features of disrupted REM sleep. But a lot of people with narcolepsy do report lucid dreaming and that's probably related to the fact that their REM sleep is slightly unstable. what about nightmares in my experience i know that i'm getting them if i've eaten too much at dinner that's all i know but then i get a nightmare so you know nightmares are really defined as dreams with an unpleasant emotional content and of course it's normal to experience nightmares every so often anything that again destabilizes your sleep in particularly your REM sleep is likely to have an impact.

41:34But we know that nightmares often, not invariably, but often go hand in hand with stress or anxiety or depression. And so, you know, it's undoubtedly the case that your dream narrative is affected by your psychological status, but it can also be affected by what else is going on in your body. I've heard many times the phrase, I need to sleep on it and then basically you before you go to sleep you have these worries then you go to sleep and you wake up and magically they're not totally gone but they are toned down they're watered down is this because in our REM sleep our limbic system our amygdala so our emotional the emotional side of our brain gets reset?

42:24Yeah, I mean, I think that this is what I was saying before about, about one of the functions of dreaming, which is that it's a form of overnight therapy. So there is a downgrading of emotions during REM sleep. And certainly REM sleep is the stage of sleep that's most associated with abnormalities of emotional regulation, that one of the functions of REM sleep is to regulate those areas of the brain that are responsible for our emotions. Interesting. So as an entrepreneur, I take various decisions throughout the day. Obviously, all of us as humans, some of them are personal, some others are professional.

43:08Those decisions throughout the day, they're building up different emotional charges that I think towards the end of the day, aside also from being more tired, they impact my decision making is it safe to assume that we should be making the best and most high caliber decisions in the early stages of our day um i think what's certainly the case is that you should not be making those sort of emotionally charged decisions when you're sleep deprived yeah um because uh you know for for a number of reasons so um first of all we talked about local sleep in in wakefulness and the fact that different parts of the brain can exhibit sleeping activity during apparent full wakefulness, and that the more sleep-deprived we are, the more our cognitive function is impaired.

43:59There's also issues of emotional regulation with sleep deprivation. Long-term, we also know that one of the functions of sleep, particularly deep non-REM sleep, is to cleanse the brain of certain proteins, certain substances that build up during the course of the day and it's out of this knowledge that there is viewed this strong association between sleep deprivation and conditions like alzheimer's disease because those proteins those metabolites are not being cleansed properly and so on a number of levels having good quality sleep is important for your overall neurological function but also your cognitive processes and so making these kinds of decisions when you are very sleep deprived is a really bad idea.

44:50I want to revisit one of the topics we've mentioned, which are the tracking devices. I think we live in a day and age in which we are constantly seeking to track the performance on various different aspects of our lives. My partner, my girlfriend, she tracks her sleep. I am of the opinion that why to track something that I cannot do something proactively is more reactive. I've seen that I've slept very bad. And if I see that, probably my performance during the day is going to be worse because that's going to be in my head. What do you think about these tracking devices? Well, you know, look, what you have to remember is that all of us see, take a viewpoint based upon the prism from where we come from.

45:40And for many of my patients who are already quite stressed and anxious about their sleep, the last thing they need is a device telling them, oh, you slept very badly. Because, you know, unless there is a solution based upon that data, as you say, it's deeply unhelpful. In fact, it can sometimes help convince people that their sleep is even worse than they think it is and can raise their anxiety around sleep. So as a general, you know, my general view is that if you have a sleep issue, probably a sleep tracker is not ideal. There are some individuals for whom sleep trackers are useful. So, for example, if you know that you have a tendency to burn the candle at both ends because of your social life, your working life, and you see that you are sleeping less than you think you are, not because you've got insomnia, but just because you're going to bed very late or waking up very early on a regular basis, then actually that can become quite a powerful tool for change if you use it properly.

46:45But, you know, as a general rule, I'm, you know, my view is that for most people, sleep trackers are not particularly helpful. How good are they at tracking? Well, I think they're very good at telling you how much time you spent in bed. They are reasonable and obviously they vary and the technology is changing all the time. They're reasonable at telling you roughly how much time you slept. although we know that one of the big difficulties with the sleep trackers is that they're not very good at telling you if you have a brief awakening at night they're not that good at differentiating wake from sleep in the middle of the night a lot of these devices are rather poor at telling you what sleep stage you're in so you'll often see the sleep tracker data tells you this is the proportion of REM sleep this is the proportion of non-REM sleep but we know that there are some issues with accuracy if you've got a sleep disorder so say you've got sleep apnea or insomnia or restless leg syndrome then their accuracy diminishes even further and so there is not only the issue of how you're going to use the information but how accurate that information is and you know one of the things that has been written about quite a lot recently both in the medical literature and also in the media is this phenomenon of orthosomnia, which is where people take the sleep tracking data.

48:16It's uncertain how accurate it is. And they make diagnoses based upon that data and convince themselves that they've gotten a diagnosis. So they can cause problems. Let's assume that for whatever reason, I have a bad night's sleep. What can I do the day after to offset the negative consequences of this bad night's sleep? Well, I think the first thing to say is it's normal to have a bad night's sleep every so often. You know, that in and of itself does not indicate that you've got any sleep issue. it's a normal response to you know particularly stressful event or something else that's going on in your life and so um you know there are certain things that you can do to try and help your function after a bad night's sleep and those are typically you know things like exercise exposure to bright light which is a little bit more difficult in london than it is in madrid and also using caffeine judiciously.

49:19So caffeine is quite a good short-term antidote to sleep deprivation, but you don't want to overuse it because, first of all, it'll make you anxious if you overuse, and secondly, if you really overdo it, then it'll affect your sleep the following night. How many coffees would you advise for us to take daily, and when should be the last one? I think it's very variable because, again, there are genetic factors that influence how we process caffeine and also genetic factors related to how significant the influence on our sleep is but by and large if you are you know an individual who knows that they have a sleep a tendency towards poor sleep then ideally you should be stopping caffeine around lunchtime because depending on how much you drink then it can hang around for many many hours and so typically for my patients I say well look you know avoid any caffeine after lunch and limit yourself to two or three coffees before lunch.

50:24I mean depending on the cultures people have lunches at different times so if we were to frame this in a different way how many hours before you go to bed you should take your last coffee? So I would say at least eight to ten hours of course those cultures where lunch is very late, tend to go to bed a little bit later as well. Do fit people or people that exercise regularly sleep better? Well, there is evidence that exercise, particularly aerobic exercise, helps sleep. It increases the proportion of deep non-REM sleep. and certainly exercise is one of the factors that's associated with a better night's sleep you know that's not to say that i don't see super fit individuals who have major problems with their sleep um and you know the the typical phenomenon that i see quite regularly that is perhaps most applicable to the people listening or watching this is that a lot of people who are of a sort of type A personality who are very competitive, who are seeking to improve their lives in every way, are also individuals who are quite prone to anxiety, particularly performance anxiety.

51:50And so they tend to be quite tough on themselves in every aspect of their lives. And those individuals can sometimes have a tendency towards insomnia and so you know exercise yes will improve sleep but it's not always associated with good sleep what about obesity and not necessarily if obese people sleep worse but does sleeping less make you eat more perhaps the day after because I've felt that sometimes. Yeah. We know that a sleep deprivation, significant sleep deprivation, even after a single night, can increase the amount of calories that you consume by about 40%. So it's certainly the case that sleep deprivation has some fundamental shifts to certain hormones that regulate your appetite, hormones called leptin and ghrelin.

52:50And if we look at long term it the there was a famous study done where they looked at i think it was 19 000 nurses in the u.s and they correlated their weight and their weight gain according to how many hours a night they slept and they tracked them for over a decade and what they very clearly showed was that those nurses who were sleeping five or six hours a night put on significant weight over that I think it was 16 years that they followed them up for over that 16-year period. And so certainly sleep deprivation, chronic sleep deprivation, is a potent factor when it comes to weight gain. It is, however, important to distinguish sleep deprivation from insomnia.

53:42And those are two different states of being. and actually a lot of people with insomnia are actually quite slim compared to those individuals who are chronically sleep deprived because I think that there are metabolic differences between chronic sleep deprivation, which is where actually you're not giving yourself enough time to sleep, but when you get into bed you're falling asleep very quickly, and insomnia. Are we consuming more calories because we have less control over our emotions because we didn't restore, we didn't reset our emotions through basically going through the REM sleep and so on?

54:25Or is it because we've slept less and our body's telling us we need more calories to function during the day? I think it's probably both. Okay. But, you know, we certainly have good evidence that sleep deprivation induces changes in the hormonal regulation of our appetite. What about timeframes? One of the changes that I've done in the last years is try to have a gap of at least two hours, at least two hours from my last meal to when I go to bed. Is that healthy? Is that the right thing to do? Well, I think it certainly, you know, again comes down to the fact that, you know, one of the crucial things I very strongly encourage people to do is to understand their own sleep, to see their sleep on an individual level, as opposed to just looking at populations, because we're all different.

55:22certainly for some people having a very large meal at night particularly one that is very rich in carbohydrates can disrupt the quality of their sleep and we think that some of that is related to you know the feeling of abdominal distension and being a bit uncomfortable when we go to sleep for some people it's related to reflux so if you've got a very full stomach you're more likely to bring up acid but also probably related to the regulation of glucose overnight and so for some people, yes, a very large meal late at night can have a substantial impact on the quality of their sleep. My twin brother, who has a tendency to sleep not very well, I would say, he just started just a month and a half ago the keto diet.

56:15And he says that his sleep has changed drastically. Now, I'm not too sure if this is related to the diet or a placebo or a bit of both. Are there any studies that confirm that the keto diet can help you sleep better? So I've not come across any. That doesn't mean that they're not in existence. But look, I think that whenever you talk about significant dietary manipulation like the keto diet, and I think that this is the case for medicine as a whole is you need to look at the whole person rather than just one particular aspect and so I'm very cautious about countenancing such dramatic dietary changes that may well have other aspects on people's health in order to pursue good quality sleep.

57:13Talking individually about my brother I think the biggest change was the keto diet, but not because of the type of food that he's taking. But he was telling me that he right now enjoys much more going out to restaurants because he can eat things that perhaps he wasn't eating in his previous diet because he was on a calorie deficit diet. And that makes him happier. So I feel like if he's happier, he's by definition perhaps less stressed. Maybe, maybe. We're complex beings. What about sex and sleeping? Are they intertwined in the way that regular sex equates to good sleep or vice versa, bad sex?

57:54I think it very much depends on the person. So certainly, you know, for some people, sex is a very good way of maintaining good quality sleep. But, you know, again, it comes down to the individual. So can I prescribe nightly sex in order to improve your sleep? No. You should. Well, it doesn't come on a prescription pad, unfortunately. You get a lot of new patients. Talking about sex. So most of our vital functions, eating, having sex, for example, they've changed a lot over the course of time. Let's say hundreds and hundreds of years. They've evolved in a way, the way that we do them, how we understand them.

58:36How has sleeping changed over time? So I think that obviously the industrialisation of society and the fact that you have much more widespread access to electricity and electrical lighting has had significant effects. You know, there's a lot of time you read studies that say, well, you know, the amount of sleep that we're getting is less than our ancestors. But you have to remember that our ancestors weren't sleeping on, you know, memory mattresses off the floor. They were sleeping on, you know, straw sacks on the floor in unheated environments. And so, you know, undoubtedly, whilst the patterns of sleep have changed, it may be that the quality of the sleep that our ancestors were getting is much poorer than our own.

59:36And so it's very difficult to draw too many conclusions about the fact. You know, what's undoubtedly the case is that there are, you know, as we started off by talking about, was that there are a number of influences of modern society that conspire against sleep. And the starting point is to be aware of what those factors are in order to try and optimize the sleep that you're getting. I've heard multiple times the term sleep hygiene. What is it? It's a horrible term. It's a horrible term, but we use it a lot because we all know what it means, or at least us doctors know what it means. So sleep hygiene really defines those behaviors that are conducive to a good night's sleep.

1:00:21And a lot of these we've already talked about before. So making sure that your bedroom is dark, that your bed is comfortable, that you're in a quiet environment, that you're not using your bedroom for anything other than sleep, that you're avoiding caffeine at the appropriate times, that you're avoiding nicotine at the appropriate times. Not even sex in the bedroom or that. Sex is fine. You're probably not doing that all the time, unless you're very lucky. But really nothing that is a regular thing that is quite stimulating and is the antithesis of sleep. That you are not consuming a lot of caffeine, that you are reducing your alcohol intake.

1:01:06No TV in the room? ideally no tv in the room um so so anything that is part and parcel of these sort of behaviors that are part of everyday life exercise during the day is all termed sleep hygiene these are things that are very easily within your control that you can manipulate in order to improve the quality of your night's sleep i have to say that if you've got chronic insomnia whether or not you institute good sleep hygiene is not necessarily going to be a game changer. There are lots of people who've got terrible sleep hygiene who sleep perfectly well. And so if you are a bad sleeper and you've introduced all these changes and your sleep is still poor, then it's important to know that there are other things that you can do, that the treatment options don't suddenly terminate once you've put in place sleep hygiene guy we've discussed extensively all things sleeping if you were to compress all your knowledge from all the years of experience that you've had in this subject matter into one advice that we should apply or we could apply on a daily basis what would it be i think it would be distilled down into make sure that you as an individual understand what your sleep is.

1:02:32What I mean by that is to understand how much sleep you actually need, to understand what factors for you as an individual impact the quality of your sleep, and to ask yourself, am I going to bed at roughly the same time every day? Am I going to, am I waking up at roughly the same time every day? Am I waking up feeling refreshed? And am I able to stay awake during the day.

1:03:04you've mentioned previously that as we grow older we need less sleep and you've also mentioned that when we sleep, especially in non-REM, but in particular in the REM phase of our sleep or in the REM stage, two things are happening. On one hand, we recalibrate our emotions, but also it allows us to build up our memory and it's a way of training our memory or cementing our memories. Does this mean that as we grow older, we have less control of our emotions and also less capacity for memory? um so i don't think the two necessarily equate you know we we know that certainly as we get older the neurological mechanisms that maintain our sleep that control and regulate our sleep become a little weaker and so that you know the the the decline in terms of how much we sleep between, let's say, 40 or 50 and when we're 80 is not insubstantial.

1:04:13Now, some of that is related to the fact that perhaps the older brain does not need quite as much sleep, but a lot of it is probably related to the fact that the older brain is less able to get good quality sleep. And so certainly there is an issue surrounding the effects of sleep on cognition and cognitive decline. The other thing to say is, look, we know that, for example, when you look at REM sleep, so when we're newborn, we spend about eight hours of the 24-hour period in REM sleep. and that in infancy that drops, but it's still very, very high. And then as we get past adolescence, the amount of REM sleep that we get drops significantly and then continues to drop throughout life.

1:05:03Now, the question is, well, why is that? And one of the reasons may be that actually we need REM sleep a lot less because our model of the world is already established and we're just making fine-tuning. we're learning a lot less later on in life about the nature of the world around us. And so it's always difficult to say, well, look, is this because we don't need it as much or is it because it's causing problems? So it's a question of, you know, association or causation. I'm Spanish. And as you probably know, in my culture, naps, daytime naps, siestas, or a thing. in fact in some households they're encouraged are they bad for us?

1:05:51you know Spain is interesting because if you look at how much sleep people on average get in various European countries the Spanish are amongst the most sleep deprived in Europe maybe it's due to our Ciestas well I think it's probably because you spend a lot of time partying late at night Right. So, you know, I think that siestas, there is good evidence that siestas are a good thing because, for example, they improve cognition, they reduce your blood pressure in the afternoon after a siesta. If you are napping regularly during the day, and that is part and parcel of your regular circadian rhythm, then there's nothing wrong with that.

1:06:35As long as you're getting an adequate amount of sleep in total per 24 hour period. If you are napping regularly during the day, despite getting what appears to be a normal amount of sleep at night, then you need to ask yourself, well, why am I needing so much sleep? Is there something going on at night that is causing me problems? So if you're sleeping an hour during the day, and then when it gets to 1am, you're able to fall asleep regularly and not have any difficulties and then in total you're getting, you know, of the order of seven to eight and a half hours over a 24 hour period, then I think that's okay.

1:07:20It's probably quite a good thing to have a siesta during the day. What my grandmother would tell you, because she kept telling me this every time we went on holidays when we were kids and she was forcing us to have these siestas to my brother and my cousins um she would tell us that if you want to stay later at night with adults you need to have a siesta so basically for her it was a way of balancing the hours that you're not going to sleep at night you sleep them during the day absolutely and you know and i think that in in spain in particular that serves a very useful function because of course in summer much more life happens at night because it's so hot during the day yeah and you know provided you are balancing what you're losing at night with something during the day.

1:08:03I don't think that's a catastrophe. Again, it comes back to regularity. So I know I've mentioned regularity a lot already, but it's the regularity of sleep patterns that seems to be one of the most important factors for good quality sleep. What about the duration of a nap? So sometimes Sometimes I have a nap that is 30 minutes and I feel incredibly refreshed. Sometimes if it's over an hour, I wake up and I feel like I don't know where I am. Yeah. So the duration of a daytime nap is really important. And it goes back to what we were talking about earlier, which was about how long it takes to get into particular sleep stages.

1:08:48So ideally, from a daytime nap, you want one of two things. You either don't, you want to avoid going into very deep sleep. So, and we tend to go into very deep sleep, into the deepest stages of sleep, something called non-REM stage three, within about 30 minutes or so. So sometimes spending 20 minutes in stage one and stage two non-REM sleep can be very refreshing. If you go for longer than that, if you go to 30 to 40 minutes or so, then you increase your likelihood of waking up from very deep sleep and that is strongly associated with what we term sleep inertia so that grogginess that you feel when you wake up the other reason to try and avoid non stage three non-REM sleep during the day is because it'll make it more difficult for you to drift off to sleep at night because it dramatically reduces the sleep pressure that normally accrues over the course of the day.

1:09:47So if you are, but if you really need a longer nap, then ideally you want it to be about an hour and a half, something like that, because by that stage you would have gone through your non-REM and you would be either in REM or in light sleep again, and it's much easier to wake up. So what you want to try and avoid is waking up from that very, very deep sleep interesting in spain sometimes when people go out and party the day after they tend to usually nap and some of my friends they tell me that they do it because um they want to catch up on their sleep but then i have this other friend that told me that you can't catch up on sleep like the hours that are lost are lost you cannot add a few more hours the day after um i think both of your groups of friends are right so so you you can you you're never going to fully repay that sleep debt but actually you can mitigate against the effect um the the crucial so actually let's take a step back so you know a lot of people talk about paying back their sleep debt when it comes to lying in at the weekend.

1:10:59And certainly, if you are slightly sleep deprived at the weekend, you can make up for it by sleeping longer at the weekend. But if you're particularly sleep deprived during the week, then no matter how much sleep you get at the weekend, you will still go back to work on Monday morning with some effects of sleep deprivation. So it depends on how sleep deprived you are. The second issue that I think your friends have to consider is whether or not they are individuals who can do that nap for a prolonged period during the day and then go to sleep regularly the following night. Because some people can do that, others can't.

1:11:41What they'll find is that if they try and catch up on the sleep that they've lost, then the following night their sleep will be much poorer. In fact, that also applies to this sort of catching up at the weekend issue, which is that a lot of people who try and do that When it comes to Sunday night, because they've woken up very late on a Sunday morning, they will have a particularly bad night's sleep on the Sunday night, and that impacts yet further on their ability to function on Monday morning. So, you know, again, it comes down to the individual and the fact that no one rule fits all. And why does alcohol lead to a bad night's sleep?

1:12:17There are a number of reasons why alcohol results in sleep disruption and sleep fragmentation. the first is a direct chemical effect on on the brain it predisposes to lighter sleep rather than deeper sleep it predisposes to sleep fragmentation but also it disrupts sleep in other ways so having a full bladder at night it's not particularly conducive to a good night's sleep if you snore it can exacerbate snoring and can sometimes trigger obstructive sleep apnea and and so on all of those levels whilst you know look alcohol is a central nervous system depressant so some people say oh alcohol is great for helping me get off to sleep and that is the case for some people but it dramatically reduces the quality of the sleep that you are getting is there one alcohol that is less bad at this yeah less alcohol less alcohol like they're all so if i have a beer well alcohol is alcohol you know it depends on how much alcohol you've actually consumed right Right.

1:13:21Interesting. What about the weather and altitude? So does someone that lives in Brazil sleep differently than someone that lives in the UK? Yeah, undoubtedly, yes. And that comes down to cultural factors. Okay. When it comes to altitude, so living at heights, we know that for many people who are not adapted, you know look the human body is an amazing thing it adapts to its circumstances over time but what a lot of people will experience is that when they are used to living at sea level and they go to altitude now for example when you go on a skiing holiday yeah um your sleep deteriorates significantly when you're in altitude if you were to stay there for six months it would normalize again but it's that acute change in altitude that influences your sleep quality now some of that is probably related to the fact that we know that some people when they go to altitude because of changes to the composition of the the pressure of oxygen in the air that they're breathing it can sometimes disrupt the breathing in sleep it can cause central sleep amnia and that can disrupt sleep quality of course a skiing holiday is also disrupted by lots of alcohol yeah but you're doing a lot of exercise as well so there are those two other factors are alarms a healthy tool to disrupt our sleep so what do you mean to disrupt your to wake us up yeah um look ideally we would all live in a world whereby our sleep is so regular that we would wake up at the same time every day um now you know modern in modern society that's not quite so possible and you know we have to accept that some deviation from regularity is normal and so you know in the absence of any other option an alarm is a is something that enables you to function it it goes without saying that you know the the ideal is to go to bed at the same time wake up at the same time and wake up naturally that's much better the the the the other aspect of this is what you don't want is you don't want an alarm to wake you from very deep sleep because that is when you're going to get grogginess or sleep inertia.

1:15:43And so trying to establish even some degree of regularity I think is better than going to bed at 4am on one day, midnight at another day, because you're much more likely to be woken by an alarm out of very deep sleep. One of my New Year's resolutions is to useless my phone. so I one of the changes that I've done is I never use my phone when I'm in my bedroom so when I go to sleep or when I wake up I don't have my phone next to me which means also my girlfriend which means that we're not using our phone alarms so we had to buy a regular alarm and when my girlfriend was setting it up the other day there were like 15 different sounds that you could choose from so I was thinking well I'm pretty sure this must have one effect or another depending on the sound that you choose because some of them were like incredibly harsh like wake up and the other ones were like very melodic and and some of them were like birds and trees yeah is there a better one for us to wake up with yeah you know my personal preference is not to be woken up by a klaxon or something deeply stressful um you know it would make sense and i don't think this has been systematically studied in any meaningful scientific way.

1:17:02But it would make sense that actually you have an alarm that escalates very gradually because if you have a very quiet alarm, then if you're in a very light stage of sleep, that's likely to wake you up. Whereas if you're in a deeper stage of sleep, it's less likely to wake you up. But it may result in a gradual surfacing, a gradual reduction in the intensity of sleep. And so you're much more likely in the end to wake up from a lighter stage of sleep rather than from a very deep stage of sleep. And also less likely to be woken up with this sort of jolt of adrenaline that is not a good setup for the day.

1:17:38What about the room? How does the perfect sleeping room look like? So very dark. We know that exposure to light at night not only influences sleep quality, but also has some bearing on certain aspects of our physical health. So there was an interesting paper that came out of China a year or so ago that demonstrated that regular exposure to light at night actually increases your risk of metabolic abnormalities. So, you know, ideally with blackout blinds or a blindfold at night to try and block out environmental light, quiet. and you know the average temperature that people prefer to sleep at is somewhere between 16 and 18 degrees centigrade although you know for some people that's too cold and they will wake up in the night cold so again it's about understanding about what works for you the other aspect of it is again talking about association between the sleeping environment and sleep rather than being awake is trying as much as possible to ensure that your bedroom is only used for sleep and it's not used for working or socializing or watching Netflix you know all of these things because ideally you want your brain to associate being in that particular room in that particular bed with sleep rather than being awake.

1:19:04Does this mean then COVID lockdowns because most people were using their rooms for more than one activity impacted our sleep because of that? I think that was a very important um very important factor you know we published a couple of papers on on sleep in covid and you know that the the increase in sleep complaints over covid was massive some of that was undoubtedly the fact that for many people it was a very deeply stressful experience you know you're working in hospitality it must have been very stressful indeed um both financially worried about their family health worry about their finances um and so that would have had a big bearing.

1:19:46But I think for a lot of people, especially young people who didn't necessarily live in big houses, they lived in one or two bedroom flats, perhaps sharing a flat with somebody, the bedroom became an office. It became a location for a multitude of different aspects of their lives. And that would have certainly have contributed to that sleep disturbance in COVID. For someone that is going through precisely that, they are under stress and they wake up multiple times at night. Is there a good technique to put them back to sleep? So if people have chronic insomnia, a few years ago, they would have come to a doctor and the doctor would have given them a prescription for sleeping tablets.

1:20:37We know that actually sleeping tablets, they work very well in the short term. They're not a good long-term strategy to helping people sleep. And there has been a move towards a technique that aims to restore that positive association between bed and sleep and break down that negative association. And that's a technique called cognitive behavioral therapy for insomnia. Essentially, this is a form of brain retraining to associate bed with a place of calm a place of relaxation rather than a place of frustration or anxiety and to again retrain the brain that that feeling of your head hitting the pillow is associated with drifting off to sleep rather than staying awake and we know that cbt this technique called cognitive behavioral therapy for insomnia or cbti for short is actually a really effective way at dealing with sort of ongoing long-term sleep issues so some somewhere in the region of about 80 to 85 percent of individuals see a significant improvement in their sleep with just this technique alone which is normally given to people over a matter of weeks and can be delivered in a variety of ways there are apps out there that can deliver it there are you know a whole range of specialists who can deliver it as well and so I would very strongly suggest that if you have tried, if you have ongoing chronic problems with your sleep and you've tried the simple things like avoiding caffeine, not smoking just before you go to bed, not using your gadgets in the room and all these other aspects of sleep that we term sleep hygiene, then you should be going to try CBTI.

1:22:23So let's say that you want to try the CBTI without seeking professional help. So you have some apps, perhaps also online you can find something. Would you say is that enough? So it depends. Look, the reason why these apps and online courses have been developed is because not everybody has access to seeing somebody face-to-face. And I think that these are a very reasonable place to start. Because if you don't respond to those apps, then yes, by all means, go and see somebody face to face because there may be some individualized treatments that you need. But as a place to start, I think they're excellent.

1:23:06And what's a good rule of thumb to determine whether this is working or not? Should I try it for a week, for a few days? No, I think with CBTI, you need to be trying it roughly for at least kind of 12 weeks or so. So we know that often what happens is that sleep improves significantly over the first few weeks. then there's a little bit of a deterioration because of certain aspects of CBTI that can transiently worsen sleep and that the maximal effects of CBTI on your sleep are usually after several weeks after you've completed the course. So this is a long-term strategy. It's not an instant fix.

1:23:43And while you're on this CBTI program, so to speak, is it good to use a tracking device? Ideally not. I mean, there are some individuals who say, well, actually, you know, using a tracking device is helpful to guide treatment. But I would argue that if you are already stressed about your sleep, then you should be focusing on your subjective experience of sleep rather than on objective measures. You've mentioned that you're not particularly fond of sleeping pills because they work pretty well short-term but not long-term. Yeah, so that's a bit of a generalization. that certainly the sleeping pills that are most commonly prescribed by doctors have significant issues associated with them.

1:24:33So the first is that they often wear off very, very quickly. The second issue is that they do have a tendency to generate dependency, and some of them are addictive, whether that's physically or psychologically addictive. What do you mean they wear off? So what I mean by wearing off is that people will require an ever-increasing dose in order to get the same effect, something called habituation. The bigger issue is that a lot of these drugs have been associated with concerns about cognitive decline in the long term. Now, I think that there are some very good reasons to suspect that certain drugs could contribute to cognitive decline.

1:25:15it's a little bit difficult to unravel that from other potential explanations which is that insomnia in and of itself can be associated with cognitive decline and so is it the use of these drugs is it the insomnia itself or is it both and the other big issue of course is that we know that in certain neurological disorders there's a very long prodrome of precursor state that can sometimes be occurred decades before so could insomnia be a precursor of what is underlying um what what the underlying pathological processes within the brain are so it's a little bit uncertain now there are some drugs that we think are probably safer in the long term that have less likelihood of developing these kinds of issues um and there are some individuals for whom these drugs are highly appropriate.

1:26:11So, you know, particularly if you're one of those individuals who has tried non-drug-based techniques and you're still sleeping very, very poorly, then, you know, I'm not ideologically opposed to these drugs, but I think they need to be used judiciously in the right circumstances and should not be the first port of call for anybody. Cognitive decline is one of the side effects. Can you give me some examples of cognitive decline? So I think the big concern is that actually these predispose to conditions like Alzheimer's disease in the long term. And certainly there is some data to support that view that these drugs might increase your risk of Alzheimer's disease in later life.

1:26:53But even in the short term, one of the most widely used drugs in the world for insomnia is a drug called Zopoclone. and zopoclone has been associated in multiple countries with an increased risk of car accidents in the morning because it influences our performance in the morning as a result of a hangover effect. Now if it was entirely due to insomnia, that effect, then you would expect perhaps people to be more likely to have crashes, road traffic accidents in the evening rather than the morning. But with zopoclone it seems to be the case that specifically in the morning, it has an impact on your ability to drive safely.

1:27:37Are these negative consequences or side effects applicable both for prescribed drugs and over-the-counter? Yeah, I mean, there are some concerns about over-the-counter drugs as well. I mean, I think that most over-the-counter drugs in the UK, most over-the-counter drugs are antihistamines. and anti-histamines in particular are associated with habituation so that is that wearing off effect that we talked about you know in in um in spain for example you can buy things like melatonin over the counter melatonin actually is you know there's much less concern about melatonin and melatonin is generally thought to be a much safer drug as you know in canada or in the states you You can walk into any supermarket health food shop.

1:28:29It's seen very much as a health supplement there rather than a drug. And so we tend to be a little bit more relaxed about melatonin. But again, anything that you take orally to help you sleep, if it works, it'll only work when you take it. And so what we're looking to try and do is to try and achieve a more long-term strategy to improve your sleep. and that's why CBTI has become the gold standard first-line treatment for anybody with insomnia because ultimately you're addressing the underlying cause. A lot of my friends, they take melatonin in different forms. Melatonin is a hormone, right? So if we take this hormone regularly in the form of a supplement or a drug, does this mean that we're going to produce it less naturally?

1:29:19Well, I think that that's one of the concerns. I don't think that has systematically been demonstrated, but it is one of the concerns. But, you know, at the end of the day, we have individuals who have been on melatonin very long term, for example, if they have circadian rhythm disorders, body clock issues, or, you know, melatonin can be used in other contexts as well. And, you know, we're not aware of any long-term harms associated with melatonin. There have been some concerns about melatonin might increase your risk of autoimmune conditions, but I don't think that's really ever been demonstrated.

1:29:57I understand that there's not one solution that fits or suits all cases, but for the general public that they are consuming these over-the-counter sleeping pills, for how long? What's the maximum length that you would advise them to take this? So we know that drugs like Zopoclon or Zolpidem, their potential for dependency can occur after a few weeks. And so for most people, I would say that the standard sedatives, things like benzodiazepines or Z drugs, should really only be used for up to two weeks at a time. There are some exceptions to that, and there are some individuals in whom I will give long-term drugs, usually if they've tried lots of other things, and that's not helped.

1:30:51But by and large, you should not be using these drugs for more than two weeks. I think that that's probably the case for the over-the-counter antihistamines as well, that if you are having ongoing issues, you should probably be talking to a sleep specialist or a doctor to see if there are any better long-term strategies that you should be using. With melatonin, I think those concerns are slightly less. And as I said, we have quite a lot of people who are on long-term melatonin, although in the UK it's licensed only for up to 13 weeks. Having said that, melatonin is often prescribed off-license.

1:31:34and to reiterate the concerns are much lower surrounding melatonin than some of the other sleeping tablets. Is there one brand that right now is sold here in the UK that you would regard as safer? No, no, I don't think that's the case. I think the first thing is, in the UK, you're much less able to buy stuff over the counter anyway. And most of the stuff, as I said, that you can buy over the counter are antihistamine-style drugs. And, you know, as a group, the antihistamines all have those issues surrounding the wearing-off effect, the fact that they often cause people to feel a bit hungover in the morning.

1:32:22And so is any one brand better than another? I don't think there's any good evidence for that. Have you ever taken any of these? Oh, yeah. I mean, I've taken some antihistamines. I've taken melatonin on occasion. I've never taken them regularly because I know that, you know, after a few nights it's not going to have a good effect. But, you know, certainly if you're going through a period of a few days or a couple of weeks of bad sleep, I don't think there's anything wrong with using these drugs. But I think that if you've got chronic sleep difficulties, and by chronic I mean, you know, lasting regularly, for more than two or three months, then ideally you should not be resorting to these medications.

1:33:03You should be trying CBTI first. What about magnesium? Yeah, so magnesium is an interesting one because a lot of people say that magnesium helps them sleep and improves the quality of their sleep. When you look at the literature surrounding magnesium, there are some very conflicting results. So some studies suggest that it has absolutely no effect whatsoever. Magnesium has some other health benefits as well, for example, in terms of lowering your blood pressure. So I don't think it's going to cause you any harm, provided that you take it according to recommended guidelines. But, you know, as I said, I would keep an open mind as to whether or not magnesium is going to help you specifically.

1:33:48Thank you. Thank you so much for coming and sharing all these valuable insights. I genuinely believe that this has been the most interesting conversation in my life. And the reason why I say this is because I find it very important and useful to improve the things that we do on a daily basis. We sleep every day. And I believe we are sleeping for about a third of our lives. so if we get that part right one third of our lives leads to an overall state of perhaps happiness or at least that's how i'd like to think about it and more importantly this is something that regardless of who you are what you do where you come from your economic background we all sleep and we can relate to in one way or another so i thank you for the tremendous work that you're doing and also for simplifying a topic into a way that everyone can digest understand and implement well i hope i've done that um you know i think you know ultimately we spend as you say a third of our lives doing this activity and we know that this activity is fundamental for every aspect of our waking lives from our psychological health our physical health our neurological health how our immune system works, how we heal, how we repair.

1:35:21And so it's worth putting a little bit of time into trying to optimize that. Thank you. Thank you.