Sleep Series E4 | The Sleep Disorders No One Talks About (w/ Dr. Hugh Selsick)

For the final episode of our Sleep Series, Dr. Anya welcomes back Dr Hugh Selsick, consultant psychiatrist and lead for the UCLH Sleep Clinic in London. This episode covers sleep disorders we didn’t discuss previously on the last episode with Hugh (E128). 

They discuss the different stages of sleep, strange things can happen during sleep such as sleep paralysis (parasomnias), narcolepsy, sleep apnoea, restless legs syndrome and much more. 

If you haven't already check out episodes 1-3 of our Sleep Series where we explore how sleep works, the psychology of insomnia and sleep in children.

Interviewed by Dr. Anya Borissova. Dr. Borissova is an academic psychiatry registrar at the South London and Maudsley Trust. 

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Alex is not currently taking on new psychotherapy clients, if you are interested in working with Alex for focused behaviour change coaching , you can email - alexcurmitherapy@gmail.com with "Coaching" in the subject line. 

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Transcript

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Hi everyone. Welcome back to the Thinking Mind Podcast. I'm Anja. I'm a psychiatry registrar working in South London. I'm very excited to welcome back Dr. Hugh Selsick, who is a consultant psychiatrist working in sleep medicine. Dr. Selsick's been involved in sleep medicine for nearly 30 years. He founded and ran the Insomnia and Behaviour Sleep Medicine at UCLH and previously worked at the sleep disorder centres at Guys and St. Thomas's Hospital in central London. Today we talk about the sleep disorders occurring where people struggle with having too much sleep. We talk about people who experience difficulties with strange experiences during their sleep, like nightmares, sleep paralysis, sleep walking, sleep eating, sleep sex. If you're interested, keep listening and you should get a really good overview of these different disorders, how they can be treated, and things to look out for, both in terms of yourself, but also if you're a clinician working with people who have difficulties with their sleep, the kinds of things that may often get missed. But if you've got an inquisitive mind and if you're aware of what to look out for, you might pick up something that could be quite life-changing. Dr. Salzik, thank you so much for coming back and joining us again. Thank you for having me. So when we met last time, and I'll refer people back to that episode, we spoke mostly about insomnia. We touched on a lot about what insomnia is, what the kinds of treatments for it are, what you tell people to think about when they come to you with insomnia. But when we started to touch on a little bit about sleep a bit more broadly, and I remember you telling us that in terms of what people come to you when it relates to sleep problems, it's sort of broadly split into categories of I can't sleep enough, I'm sleeping too much, or sort of weird things are happening when I sleep. And so I'm hoping today we can focus on that other side. So the sleeping too much or weird things happening, and start to get a sense for what people come to you with, what you do, how you think about these disorders, what is happening in the brain with them. So certainly for some of them, it w is useful just to look under the hood of sleep a little bit and look at the different types of sleep, the different sleep stages that we have. For most of human history, we imagined sleep was just a thing. Uh, it was a singular thing, and it was very often seen as a negative, uh, as a kind of a lack of wakefulness, if you like. And it's really only in the last 70 years or so that we've really been able to have a look at what's going on in the brain and the body during sleep, and we've come to realize that sleep is a collection of different states, uh, which are kind of mashed together. So we broadly divide sleep up into two types, rapid eye movement or REM sleep, and everything else that we call non-REM sleep. And non-REM sleep is further divided up into three different stages, stage one, two, and three. Uh, stage one is just a very light stage, it's kind of a halfway house between being awake and asleep, and we don't think it has any function of its own. Stage two sleep is a light, again, a light stage of sleep, but we spend half the night in the stage, and it seems to be really important for uh memory consolidation, uh, for cognitive function. And stage three sleep is our deep sleep, and this is the most unconscious you will be in normal life. It's very hard to wake someone up from stage three sleep. Um, again, it seems to play an important role in memory consolidation and cognitive function, but we are now seeing um indications that it's it's probably very important as well for physical repair of the brain and uh possibly also uh of the body. So those are different stages of sleep. And we're when we're thinking about sleep disorders, it's useful to have those in mind because certain disorders will arise from certain states of sleep, and we cycle through these different stages in nine 90-minute cycles through the night. Falling asleep, we go through stage one and then into stage two, then into stage three, back into two, and then rem sleep. And then that cycle repeats, although usually without going through stage one again. But what does change is that as we go through the night, we get less and less of that deep stage three sleep and more light stage two and rem sleep. Um, and so the lay the first half of the night is dominated by deep sleep, whereas the second half of the night is dominated by light sleep and rem sleep, which is our primarily when we do our dreaming. Okay. And so as we're coming to the end of the sleep is when we're having a lot of that REM sleep, as you say. So I guess that aligns with why you're often waking up from dreams. Mm-hmm. Yeah, absolutely. So you're much more likely to remember dreaming if you're woken from REM sleep, um, and you are much more likely to wake from REM sleep in uh this the last part of the night. You know, one of the things that's uh sometimes uh wearable technology advertises that they will wake you in a light stage of sleep. Uh, but you know, by the time you get to six, seven in the morning, pr almost a hundred percent, if not a hundred percent, of your sleep is light. So you could wake up at pretty much any time and you'll be waking up from light sleep. Okay, so save your money uh and just wake up when you wake up. And so then what is it that can start to go wrong with these different stages of sleep? So just to kind of go down to the foundation again, we have six broad categories of sleep disorder. We've had insomnia, which we talked about last time, so that's difficulty getting to sleep or staying asleep. We have movement disorders such as restless legs, uh, breathing disorders like obstructive sleep apnea, body clock disorders where there's a mismatch between your internal body clock and the outside world. We have disorders of what you call central disorders of hypersonnolence, things that make you very sleepy, like narcolepsy. Um, and then we have these things called parasomnias, which are unwanted uh behaviors or experiences that occur during sleep or on the boundary of sleep and wakefulness. Um, and it's particularly these disorders uh where it's useful to know what stage of sleep they're happening in. So we have some of these parasomnias occur, for example, in deep sleep. Things like sleep walking, uh, sleep eating, sleep sex, sleep terrors all arise from this very deep stage three sleep. And because they arise from deep sleep, they tend to occur early in the night, um, usually within the first hour or so of falling asleep. There are other disorders that are primarily occurring in REM sleep. So something called REM sleep behavior disorder where you act out your dreams in your sleep. Um, nightmares, uh, vivid, detailed, frightening, awful dreams, or sleep paralysis where you wake up and you can't move. These are REM-related uh disorders, and they tend to occur primarily towards the end of the night, uh, in the early hours of the morning. I I guess I'm curious about even how you might make the distinction. I guess, you know, for instance, you say sort of sleep walking, sleep eating. And I can imagine some of those things always maybe looking alike to things that happen in REM sleep, or some of the when you're sort of talking about acting out dreams. How how do you start to how do you start to tease these things apart? The first thing, as we've said, is the the timing, when it's from deep sleep the first half, when it's from REM, it's more likely in the second half of the night. The second thing is the patient's experience, because parasomnias that occur in deep sleep, by and large, the patient won't remember those. It's reported by the bed partner, the family, or because they wake up and find that they've raided the fridge in the night and have no memory of it, or things have been moved around. And if they uh if they have a sleep terror, it they look absolutely petrified. There's you know, someone with a sleep terror will sit bolt upright in bed, screaming, crying, looking absolutely petrified and will have no recollection of it the next day. Whereas with the REM-related parasomniers, people tend to remember them. They remember their nightmares. They will often if they don't wake up from an episode of REM behavior disorder where they act out their dreams, they won't remember that they've done it. But if they do wake up in the middle of an episode, they'll say, Well, I dreamt that I was um fighting someone and I was throwing punches, and the bed partner will say, Yes, that's exactly what I saw you doing in the bed. And the the other differentiator really is how organized the behavior tends to be. When you have these non-REM parasomines, something like sleepwalking, the person's eyes are open, they get up, they get out of bed, they interact with objects in the outside world. So they see a glass on the table, they pick the glass up, they see a door handle, they turn the door handle. With the REM-related, the REM behavior disorder, generally the eyes are closed and they're not interacting with the outside world, they're interacting with their dream. So, yes, they might knock the glass off the table next to their bed, but it's not because they are trying to hit the glass, it's because they're trying to hit something in their dream and the arm just happens to sweep out and whack the glass. And it's very, very rare for people to get out of bed during these REM-related parasomnias, uh, whereas it's much more common in those ones that occur from deep sleep. And how how come that's the case? How come it's less people are less likely to get out of bed during REM? I think part of the reason is that you tend to wake up much more quickly because REM is a relatively light stage of sleep. If you do jump out of bed, you you wake up. So uh a very common presentation of this REM behavior disorder is someone will dream that they are throwing a punch and they throw a punch in real life and they throw themselves out of bed and hit their head on the bedside table, or they land on the floor and then they wake up immediately. Whereas with the non-REM parasomnias, because part of the brain, part of the brain is awake, but part of the brain is so deeply asleep that when they stand up, where then they jump out of bed, it doesn't wake them. And so they will just carry on in this half-awake, half-asleep state for a period of time. I imagine it can get um quite problematic for people. It it can do. Sleepwalking is uh we think of it as something that can be quite amusing, but there are times when it does put the person at significant risk. Uh, and I've had patients who have sleepwalked off a third floor balcony and miraculously got away with only a broken leg. Um, there are times when people can be violent during these episodes, although that's really, really rare. Um, it does happen, but it's exceedingly rare. When people engage in sleep sex, which is a variant of this, uh, that can be really problematic because they might be lying next to someone at night who has not consented to having sexual intercourse with them, uh, and they engage in intercourse. And it's not that they're doing this deliberately, they're not dreaming about sex, it's just this very automatic behavior, and it does get them in trouble. On the other end of the night with a REM behavior disorder, again, it's very often what brings people to the clinic is that they are dreaming that they're fighting or playing football or whatever, and they lash out and hit the bed partner. And that's often something that's completely out of character for that person when they are awake. I've had a couple of patients who have been referred with us who have been in quite significant trouble being reported for domestic abuse, even though their partner has been really clear that that that is not the case, that they would never harm them when awake, but it's just that they're thrashing around so violently at night, and unfortunately the bed partner uh gets in the way and it gets a black eye. So it can cause quite significant distress. What can, and I guess I mean the the question immediately springs to mind of what can you do about it? What about how can you manage these situations? It depends very much on what the parasomnia is and what the underlying uh factors may be. Um very often the non-REM parasomnias, the sleepwalking, the sleep terrors, these are genetic. They run in families, and they're much more common in children. You'll often see them in young kids, and very often they will just grow out of it. And so sometimes the thing to do is just to reassure you know, if the person gets out of bed, just guide them to the nearest couch or bed so that they can lie down and go back into full sleep again. Um, and they will grow, you know, very often grow out of it. If it does become problematic, there is a little bit of evidence for for treatment in children, much less so in adults. Um, in children, there is some evidence for the use of uh supplement 5 HTP and also doing something uh called preemptive waking. And what this is is let's say the person tends to sleepwalk or have a sleep terror 40 minutes after they fall asleep on average. What you then do is you go in somewhere between the time they fall asleep and that 40 minute mark and just stir them, just wake them slightly. Uh you don't have to get them into full wakefulness, just enough that they kind of become a little bit aware that you're there, bat your hand away and go back to sleep. And we don't really understand why, but this can sometimes be really effective at stopping these episodes. And you do it for a few weeks until you've had a few weeks episode free, and then you stop and and see what happens. In adults, as I say, there is a lot less evidence. It's much more difficult to monitor in adults because particularly someone living on their own may not be aware when they're having an episode, and so it's hard to know how effective a therapy is. Whereas in children, there's always an adult around to monitor and report on what's going on. There is uh some evidence for hypnotherapy, and that's certainly something that I've used or referred some of my patients for and seen actually some really good results. And there is also some evidence for the use of antidepressants. We don't think that this is because the person is depressed, but rather there's something else going on with that medication that makes it effective. But the other thing that's important to think about is that particularly where these episodes emerge in adulthood, and especially if there's not been a history of having them as a child, is that they can sometimes be a sign of another sleep disorder. When we think about these non-REM parasomnias, what's really happening is the person is in really deep sleep and something wakes them up. But because they're so deeply asleep, what happens is that part of the brain wakes up and part of the brain remains fast asleep. And it's generally speaking the back part of the brain that wakes up and the front part, your prefrontal cortex, that's asleep. And the prefrontal cortex is the part of the brain where your personality resides, where you uh exercise control and judgment and planning and restraint, uh, whereas the back part of the brain tends to run much more automatic programs, instinctual things or learned behaviors. And so what we think is happening is that when you have a non-REM parasomnia, is that your back part of the brain is awake and it then starts acting on impulses. It sees a door handle and goes, okay, I need to run the door handle opening program. It sees the uh food and the fruit and goes, oh, I need to run the eating program. And the front part of the brain is fast asleep and has no idea that any of this is happening. What that means is that if we can reduce the number of times somebody wakes up in the night, if we reduce any disruption to their sleep, we can reduce the opportunity for these partial awakenings to occur. Um, and so when someone develops these conditions in adulthood, we always want to look and see is there something else going on that's fragmenting their sleep? Do they have obstructive sleep apnea? Are they choking in their sleep? And that's what's causing them to wake up, or do they have little leg twitches in their sleep that that's fragmenting the sleep? So part of the workup for these uh conditions in an adult would be to bring them in to do a full sleep study. For the REM-related parasomnias, the REM sleep behavior disorder, now our first line treatment is melatonin. Uh, what's happening in REM behavior disorder is that normally when we dream, when we're in REM sleep, we're completely paralyzed or almost completely paralyzed. And the reason is that if you dream you are running down the street, your brain thinks it's real. So it's trying to make your legs move, it's trying to run, which is not a brilliant idea if you're in bed or sleep. And so when you go into REM sleep, your brain sets up a roadblock to stop those signals getting from your brain to your muscles. And in REM sleep behavior disorder, what's happening is that that roadblock is not getting set up for some reason. Therefore, there's nothing to stop the person acting out their dreams. When we give melatonin, it helps to re-establish that normal paralysis. And it's a real that's a really nice treatment because actually it's a very benign treatment with relatively few side effects. For nightmares, we first go to psychological treatments, something called imagery rehearsal therapy, where you ask some the person to recall a nightmare, describe it in as much detail as possible, and then change it into something more positive, create a more positive ending or change the environment or something that makes it less threatening, less negative, more positive. And then ask them every day to rehearse that new version of the nightmare. And then after a week or two, they pick another nightmare and do the same thing. And again, um, it can be remarkably effective at reducing nightmares. We're not 100% sure why. My personal theory is that in a way it helps the person feel in control, that they are the nightmare makes a suggestion about the storyline. You can pick which things you want to accept from that suggestion, which things you want to change. And so you feel you have a degree of control rather than the nightmare happening to you. If the this treatment is not available or it hasn't worked for people, again, there are some medications that we can use. Um, there's a particular blood pressure medication called Prazicin, which is widely used for the treatment of nightmares. There's an antidepressants called trazidone, which we use quite a lot in our clinic with good effect. So it is very treatable. But again, nightmares can be precipitated by other sleep disorders. Uh, and again, uh again, obstructive sleep apnea is the big culprit here. We know that uh sleep apnea significantly increases nightmares, and if you treat the sleep apnea, often the nightmares will get better. The treatments that you talk about are in themselves, I think, really interesting. I mean, going back to the idea of using hypnosis, I wonder, do you have any ideas for why that might be helpful or sort of how how that might be working? It's received dogma that parasomnias are made worse by stress uh and anxiety. And I'm not sure there's brilliant evidence for that, but it's uh it does make a certain degree of sense. Uh, if you know, we know that stress and anxiety can disrupt your sleep, and therefore it may make um the parasomnias more frequent. Um, and it may be that the the hypnosis is just a really good way of relaxing, of reducing stress uh prior to going to sleep. So it's not so much a hypnosis using suggestion you will not sleepwalk tonight, but rather a hypnosis just teaching the person how to relax. And with um with using the imagery rehearsal, and you talk about sort of establishing a degree of control over the nightmare potentially, uh you know, certainly sort of going through the uh the nightmare and imagining an alternative ending and and rehearsing that in detail. I guess the the similarity sort of that springs to my mind is uh the uh idea of lucid dreaming. And I'm wondering if that's in any way related or if there's any similarities there. It seems to work in a different way. And lucid dreaming has been trialed as a treatment for nightmares and shown to be effective, but it's much harder to do. So with lucid dreaming, we're trying to teach the person to become aware that they're dreaming and then change the dream while they're having it from within. Um and some people can learn to do that relatively easily, and some people really can't. Whereas with the imagery rehearsal therapy, we're not changing the nightmare in the hope of incorporating that change into the nightmare when it happens. And in fact, uh it works really well for nightmares that are not recurrent nightmares. So it's not about changing the narrative of the nightmare, uh, rather it's something about changing your relationship with the nightmare or uh the degree of distress that you experience from the nightmares. How can it work if people don't remember their nightmares or sort of how much of a nightmare does someone need to remember to be able to do the to do the rehearsal? Formally speaking, you have to remember the nightmare for it to be classified as a nightmare. That's what part of the definition that they are well-remembered dreams. Um there are some people who say, I definitely do have nightmares, but I forget them later in the day. Um, and then the imagery rehearsal therapy would be very difficult for them to do. And uh we would need to think of an alternative plan for that that kind of um that kind of patient. And then I'm also curious about the use of antidepressants uh to sort of help manage some of these symptoms, in part because uh sort of the experience that I have had is almost in the reverse. That people who who are being prescribed antidepressants for, say, anxiety or depression or the other conditions, they come and say, so either if they've missed a dose of their medication that they seem to have really vivid dreams or they're having nightmares or, you know, sort of their sleep has become really disrupted. Um, or even just that as they're starting taking it, their s their sleep or their dreams or something about it changes, not necessarily in the most positive way, sometimes in a neutral way, but they just they notice that there's a change to their sleep. What's what it like, do would you have a sense for what's happening with these medications and sleep and and then how when they can be useful clearly and when not? Of course, antidepressants are is is a is a big umbrella term and and the effects of individual drugs will will vary, but the vast majority of antidepressants uh suppress REM sleep. Um they reduce the amount of REM and push REM later in the night. And this may in fact be part of the mechanism by which they work. Uh we've known for a long time that having excessive REM or having REM too early in the night is strongly correlated with depression and does seem in fact to have a causative role in depression, and therefore suppressing REM sleep and pushing it later in the night has potentially an antidepressant effect. What that means though is if you are suppressing REM in the earlier part of the night, it can make your REM sleep more intense in the second half of the night. You get almost a rebound as your brain tries to catch up on the REM that it hasn't had. And so that might be one of the reasons why people will experience more vivid, crazy dreams on antidepressants. Similarly, if you stop an antidepressant, because your REM has been suppressed, you will have a REM rebound. You'll have much more REM sleep in the days after stopping an antidepressant. Um, and so your sleep will feel very much full of dreams, perhaps less uh less deep, and you'll have you know these more vivid dreams as a result. The REM sleep behavior disorder where people act out their dreams can sometimes be a side effect of antidepressants. So it is something to look out for with antidepressants. It's very rarely problematic, but it uh it can occur on occasions. So part of how antidepressants might work is through changing uh and as you say, suppressing RM sleep because this is in some way linked with depression itself. Again, we don't really fully understand the mechanism. One theory about it is that REM sleep is a very metabolically active state for the brain. Um, your brain is not resting in REM sleep at all. It's uh it's very active, it's generating all of this crazy imagery. There are parts of the brain that are more active when you are in REM sleep than when you're awake. So possibly what's happening is if you have an excess of REM sleep, your brain is just using up too much of its energy, using up its energy stores during the night, perhaps using up some of the neurotransmitters during the night that it needs during the day, and it's therefore starting the day depleted. And this might be part of the package of things that then leads to a depression illness developing. Yeah. Yeah. And if you're um so if you're then I guess changing or reducing the amount of REM sleep that you have, and and and take me back because I I think I've I've lost track of which um which sleep disorder it might be that you're using um some antidepressants in. It it it's your REM sleep disorders again, right? Uh the non-REM uh parasomias. The non-REM. Where do you think sort of what difference is that making there? Uh honestly, uh, I don't think we know. Um I I I I don't think it's to do with the antidepressant effect because um patients often will report that the parasomias improve relatively rapidly on the uh antidepressant, much faster than you would expect a you know, mood or anxiety to improve. So um, yeah, we just don't know. So there's I guess a wealth of options available to people if they're experiencing any of these disorders. So it's well worth um reaching out to for support. Yeah. I I think now with kind of off-the-shelf technology that's going to make it easier to monitor these sorts of things, that there will be an upswing in research. It'll be much easier now to study this in adults. And sometimes some of the best ideas of how to manage these things come from patients themselves. So uh one patient uh of mine who would have a kind of a cross between night terrors and sleepwalking, where he'd jump out of bed and then rush over to the wall and try to rip the radiator off the wall or start throwing the drawers around the room, simply put emotion-sensitive light in his room. And so when he jumped out of bed, the light would go on, and more often than not, that would wake him up enough to realise, oh, hang on a second, uh, I'm out of bed, what am I doing? And go back to bed. Um, so sometimes the the solutions can be, you know, really simple like that. Amazing. Okay. And and you touched on this and you said it's something that is really quite rare, but I guess where people have perhaps come across uh sleep disorders is through news stories of really violent acts occurring. Can you speak to what what is happening in? I mean, you you touched on this with the sort of the the non-REM sleep, sort of undertaking sexual activity during sleep, and that people actually really have no idea what they're doing, and it's it's sort of very removed from anything that they would usually do in their normal life. Our our brains do weird things and our brains think things and our brains have various impulses all of the time. And um, it's really kind of that prefrontal lobe that's reining that in um and deciding which impulses to act on and which ones to suppress. And um, yeah, when you remove that higher control, I I often use the analogy that it's um a chariot driver with wild horses pulling his chariot, and you know, that's what our brain is like sometimes. And if that driver is asleep, the horses get to do whatever they want, and they will just uh act on impulse, go where they want to go, and it doesn't necessarily reflect at all on what that driver would be wanting to do. Um, and it's enormously distressing, not only if someone is a victim of uh violence or unwanted sexual contact during the night, but for the person who's doing it, it's also incredibly traumatic and makes them wonder if they worry that this is a sign of some deep-seated violent tendency or um or deviancy, and and it's really not. It's uh it's just uh an odd neurological thing, I guess, is the best way to put it. Yeah, I can see that being a really difficult conflict for people to deal with because I guess it starts to bring up questions of what makes us us, what makes us who we are as a person. I mean, how how do you how do you figure this out with patients? I think it's useful sometimes for them to read the experiences of other people who've had similar um conditions because there's often a lot of shame associated with it, embarrassment, uh worry, fear of what could I potentially do if I'm sleepwalking. A really common a really common presentation actually is when people say, Well, you know, I've been sleepwalking for years and it hasn't bothered me, but now my wife's pregnant, so we're gonna have a baby in the room. What happens if I hurt the baby? That's a really frightening thing. And people often don't feel that they can talk about it because they are ashamed. So it's really useful actually for people just to hear or read the experiences of other people and realize that they're not alone. Very often when people describe their experiences, I'm able to say to them, that's really common. You know, that this is the kind of thing that I hear, you know, on a regular basis. And that in itself can be really helpful. Um, hearing that you're not deviant, you're not that different. This is something that uh you know that's happened to other people. But yeah, it it it uh as I say, it can be very difficult. Sometimes one has to just be practical and say, well, you know, if you've got this rare behavior disorder, if you're lashing out, perhaps you and your partner need to get two single beds and separate them slightly so that you can sleep with confidence, knowing you're not going to hurt your partner. Um you know, when you remove some of that anxiety, it's easier, I guess, to internalize and go, okay, you know, this is how I am, and I, you know, it it's but it's not me as a person, this is just a condition. So sort of creating some separation from from from yeah, from this being a disorder rather than this being something to do with their personality or their choices. Exactly. Yeah. Is there um I mean I've I've I think I've sort of gone in through all my curiosities from from the some of the things that you said, but is there anything else in in these REM, non-REM sleep disorders that you think it's worth us being aware of uh that that I haven't asked you about? I'd like to talk a little bit about sleep paralysis, uh, because again, this is not uncommon. Um and it does cause people a lot of distress, but it's also a really interesting area. So what's happening in sleep paralysis is that you wake up from REM sleep. It can also happen on falling asleep occasionally, particularly in people with narcolepsy, but most often it happens on waking up from REM sleep, and there's a delay in that roadblock that paralyzes you, getting removed. So you're now awake, but you cannot move. There's very often a sense of someone pushing on your chest or stealing your breath. So you feel like that you can't breathe, and there will often be um associated hallucinations, seeing a shadowy figure in the room, feeling someone touching you, hearing things, and it's incredibly frightening. People often think that they're going mad when they have these experiences. And again, they look, they can be more common in people who have psychiatric conditions, but that's probably a consequence of just having more fragmented sleep when you have other conditions. And the first thing to say about these uh sleep paralysis episodes is that they're not in any way dangerous. No one has died from sleep paralysis. The paralysis always resolves, but it is incredibly frightening when it happens. And I think just understanding that, again, this is a neurological thing, this is not me going mad, this is not me having a stroke. Um, it's just I'm experiencing this completely normal physiological paralysis that stops me from punching my partner or kicking the wall during my sleep. But there's just it's being a little bit tardy about going away once I wake up. Just understanding that can be really helpful. Another trick if one does have sleep paralysis is to put a tennis ball in the back of your pyjamas, because for most people, these episodes happen much more commonly on your back. So if you have something uncomfortable in the back of your pyjamas, when you roll on your back, it turns you onto your side again, makes it less likely to happen. But I think it's a really interesting condition as well, because it's something that has has cropped up in cultures and folk stories and religions all around the world with all sorts of really interesting and different interpretations. So in um in some communities it's considered a ghost visitation, in some it's a witch who sits on your chest and steals your breath. In uh the the Midwest of the United States, it's probably what accounts for some of the stories about uh alien abduction because the person is paralyzed, and sometimes there's also this feeling of lifting off the bed or having an out-of-body experience. And so different cultures have interpreted this in uh in different ways. And when you when you look at uh when you look at it, you see that there's a common set of symptoms, a common kind of set of experiences, but then it gets interpreted in all of these different ways. I've had friends uh who've who've experienced this, and I've also been sort of in the room uh with a friend when when she had, you know, she was sort of like, Anya, who's there? Kind of, I think a few minutes, maybe a few moments after being able to then move from from this kind of episode and having sort of you know felt something and seen something. It's and it's so vivid, it's so scary for people when they have it. Yeah, it it really is. And um uh we uh we run a course in our clinic uh on uh cognitive behavior therapy for sleep paralysis course, where we teach people to understand their condition, look at ways of preventing it, such as the the tennis ball trick, uh, but also ways of breaking the paralysis if they do or being less distressed by the paralysis when they have it. Um so again, it is something that is is treatable. And um if one is struggling with it, it's worth reaching out. It's fascinating, and I guess this links with some of the other disorders we've talked about, but the idea that uh you can prepare for these to happen in your waking life and somehow access the learning that you've made in the moment of sleep. You know, sort of you can learn CBT type techniques, and it sounds like you're saying people can then access the knowledge to maybe reassure themselves in the midst of a sleep paralysis? They can do, yes. Uh although it does take practice because of course when you wake up, you're only partially awake, you're frightened, uh, it's not easy to remember these techniques. So very often when we're teaching these techniques, what we're really emphasizing is to do imagery, to practice it in your mind, to actually go and lie down on your bed and imagine that this is happening and do it every single day for weeks, so that at some point it starts to become automatic. And then it starts to happen when you're in one of these episodes at night. Yes, it's a it's a great example though of how um how important learning repetition is in CBT in terms of sort of establishing new pathways. And this feels like a very vivid way of showing how, say, CBT and anxiety or OCD or depression presumably works through similar ways. You you rehearse something enough that it then eventually becomes automatic and you can access it at the distressed moment without having to think about it or without having to be able to access all of your brain. I liken it a bit to uh water running downhill. Uh and if you're depressed or you have a parasomnia or whatever, the default way that water is going to go downhill when it rains is down that channel. And what we need to do when we're trying to change um things is we need to dig a new channel and we need to dig it really, really deep so that that becomes the default way the water flows. And when it does become the default way that the water flows, the water will dig that channel deeper and deeper. So yeah, you have to do that legwork though. You've got to do you've got to do that digging to make it your default. And you touched on this as well, the sort of the cultural phenomena that are linked to sleep paralysis. I feel like I've read stories about this being uh in some cultures, maybe I don't I don't know if it's the same phenomenon, but that it can also be so frightening that then it's associated with people actually believing that it's a sign of their impending death, or that um it's I don't know if it's sleep paralysis that is the the thing that I'm thinking of, and I can't quite think of the name, but uh I don't know if that's along the right lines. I mean I don't know specifically, but it's quite possible. Um I think what's interesting is there seem to be a lot more reports about it from previous ages uh than one would uh have imagined. In fact, the term nightmare um is thought to come from the old English for night presser, and that the term actually referred not to a bad dream, but to the sleep paralysis. And there are l yeah, I don't think anyone's ever done a numerical study, but uh you certainly come across more um in my experience, more uh reports of sleep paralysis than you do of nightmares in uh in literature, historical records and and so on. So I I do wonder if it was more common uh or if it did just carry that much more emotional weight or fear or uh spiritual significance in the past. So more, as you say, more spiritual significance, more less biomedical explanations for what is going on. Yeah. Yeah. So I wonder if we move to slightly another side of the coin uh when thinking about sleep disorders. Would would you share a bit about the the hypersomnia disorders? What what kind of things people come to you with, what it what that can be like? Hypersomnia being too sleepy during the day. The most common cause for hypersomnia is not getting enough sleep at night. Uh it's sleep deprivation. And that's a um that's a very treatable condition. And what I would say to anyone who comes with excessive sleepiness, unless I've got a really clear explanation, is I want you to increase your sleep opportunity modestly but consistently for at least a month. And if you're still sleepy at the end of that, then we know there's a problem that needs to be addressed. Um, and the reason I say modestly is if someone's going to bed at one in the morning and I say go to bed at 10 at night, they're not going to do that. But if maybe they can go to bed at 12. Consistently, um, six nights a week. And I say six nights because everyone needs a night out on the weekend. But if you've accumulated a sleep debt, you don't pay that debt off after one or two longer nights sleep. And so you need to do it consistently most nights of the week for at least a month to really pay that debt off to then feel a difference in the day. Perhaps the second most common cause of uh sleepiness in the day is obstructive sleep apnea. And this is where the person's throat collapses at night so that they are struggling to breathe, or in fact, the throat may close completely and they choke. And this then wakes them up and then they fall asleep, choke, wake up, fall asleep, choke, wake up, and as a result, their um uh their sleep is incredibly disrupted and they feel very sleepy in the day. The there is also something called periodic limb movements of sleep, which are little leg twitches in sleep that can fragment the sleep. The patient is usually not aware of them, often the bed partner's not aware of them. It's a very difficult disorder to pick up on history. It's something we really do need a sleep study to detect. Um, and then finally we get disorders, central disorders of hypersonnolence. This is, in a sense, a neurological disorder that makes you sleepy. And the one most people have heard of is narcolepsy. Narcolepsy is an uh it's a condition where you have too much REM sleep in all the wrong places, uh, REM sleep and REM sleep-related phenomena. So people with narcolepsy, by and large, don't tend to sleep much more or more at all than you or I do, but their sleep is very fragmented and spread across the 24 hours. So they have very broken sleep at night. During the day, they'll often wake up feeling refreshed in the morning and then they get start get to get progressively more sleepy, and then after an hour or two, have to take a little nap. And then they wake up refreshed and then get more sleepy and have to take a nap. And very often in those naps, they will go into REM sleep, which is unusual because REM sleep should really only occur after 70, 80 minutes of sleep. They will also have lots of hallucinations uh at night, uh, much more frequent sleep paralysis. Uh, and again, these are these REM phenomena. The hallucinations we think are the dreaming brain imposing its imagery on the outside world, the sleep paralysis we know is a REM phenomenon. And some people uh with what we call type one narcolepsy have a condition called cataplexy, which is where something emotional happens, and it's usually a positive emotion like amusement. Something makes them laugh, or they get a surprise, or they get angry, and that REM paralysis kicks in while they're wide awake. And that can lead to very subtle uh sounds. For example, you might just get a nodding of the head because their neck muscles are weak, or it can be as dramatic as that they collapse down onto the ground and can't move uh for a few seconds or a couple of minutes, and they're fully awake, they're fully aware of what's going on, but they've now got this REM paralysis and can't move. And there's another condition which we see not infrequently called idiopathic hypersomnia. These people are probably sleepier than the people with narcolepsy. They tend to have a very long, very deep sleep at night. They don't wake feeling refreshed. Uh, if they nap in the day, they'll nap for hours and feel worse on waking than they did when they went to sleep. And in some ways, it's often a bit uh more problematic to treat because they are so sleepy that we um we often we often really need to, you know, with someone like who's got narcolepsy because naps can be refreshing, we can use some behavioural things, we can have planned naps during the day, for example. That doesn't work for people with idiopathic hypersomnia. Planned naps, if anything, as I say, make them feel worse. Gosh, okay. So again, a a whole sort of range of different things uh that can occur to to mess with people's uh I guess with with the expected amount of sleep that someone should should have. Yeah. Yeah. Why I mean the I guess the the first question that jumps to mind is with narcolepsy and and cataplexy, do we have a sense for why the emotional stimuli are so relevant? What how are they leading to this paralysis or this activation of the of the usual REM paralysis? So I I know that the neurologists have some theories about it. I'm not uh I'm not in Intimately familiar with it. And again, I think it's a case of we have some theories, but we just don't know at this stage. And that's something that you will hear with sleep medicine that we say a lot, is we just don't know. It's such a new science, and it involves as with most things with the brain, you know, we don't have a great grasp on what causes it. There's certainly something we do, you know, we do uh we do know, for example, when you think about if you laugh very hard, often you will feel weak at the knees. That's a common that's a common experience. And one of the theories that this is somewhere on that continuum, um, that there's some similar underlying mechanism. Uh but uh yeah, it's we're saying uh we do have in the last of 25, 30 years, we have gained a better grasp on what causes narcolepsy uh at its very core. And it uh turns out that it's an autoimmune condition, that there's a very small bundle of cells in the hypothalamus of the brain that produce a chemical called erection. And one of erectsin' prime functions is promoting wakefulness. And when someone has an autoimmune, uh has gets a sore throat or a cold or whatever, and they mount an immune response, very, very occasionally what might happen is it might attack the that person's own cells. And if it happens to attack these erection-producing cells, because there are so few of them, it doesn't take a lot to knock them out or significantly reduce them. And it's this lack of erection that leads to that type one narcolepsy with cataplexy. The orxin, the these neurons uh feed into other areas of the brain that release all sorts of other neurotransmitters such as noradrenaline and serotonin. And it may be those uh that those neurotransmitters or dysfunction in those neurotransmitters from the lack of orexin that then leads to the cataplexy. Yeah, I mean I remember the last time you were talking about orxin being one of the targets of some of the newest sleep medications that exist, the diridirexant medication. But I guess that's not helpful for people with narcolepsy uh and cataplexy. No, and in fact, it's one of the uh absolute contraindications to using it is if someone has narcolepsy. What we are hoping will be available in the not too distant future is so uh diridirexant is an erection antagonist that blocks erectsin property uh uh action to promote sleep, is uh that there will be some erection agonists which will promote uh erxin's activity and that that might provide uh an effective treatment for narcolepsy. What what do you have at the moment? What do you do when people I know you talked about potentially planning in naps, is that is that the mainstay or are there other strategies? So naps, um exercise, but but ultimately most patients need medication. And so we will give stimulant medication to promote wakefulness. Um, and we have a range, we kind of have a ladder of drugs that we tend to go up in order to to treat it, starting with the you know, the least potent and building up as we go. For those who have that type one narcolepsy and have these um uh have the cataplexy, this collapse, this loss of muscle tone during the day, because we know that this is a REM phenomenon, we give medications to suppress REM sleep. Uh and the medications that we give that suppress REM sleep is the one the group that we've discussed already is the antidepressants. So uh we will use antidepressants again, not because they're depressed, but because it suppresses REM and REM phenomena. If patients don't get good control of their cataplexy on antidepressants, we can use something called sodium oxibate. And sodium oxibate uh is uh related to GHB, the uh which is a sleeping draft, it's a sedative. And it may sound like a very weird thing to do to give sleepy people a sleeping draft, but they take it at night and it helps to consolidate their sleep, it pulls all of those REM phenomena back into the sleep period and can be very potent at reducing uh the cataplexy and also does seem to improve wakefulness during the day. And I I I think this potentially is an area that people have a bit of a misunderstanding of, but to to underline and to check that I've understood in cataplexy the the person isn't dropping isn't dropping off to sleep. They're just losing their muscle tone. So they're just losing, they're becoming paralyzed, but actually that they're not asleep, they're not entering a dream state. It's an it's a paralysis attack, not a sleep attack. So they they will have periods where they are incredibly sleepy and you know, will sometimes have an imperative need to sleep where they just go, it's happening now, I've got to lie down on the floor because I'm gonna fall asleep. You know, uh for some patients with really severe narcolepsy, that does happen. But for most of them, that's not the case. For most of them, if they are feeling very sleepy, they are able to kind of stay awake long enough to go and you know, walk off somewhere, hop into the bathroom, sit and you know, uh sit in the twelve, lean their head against the wall before they fall asleep. So they it it will often be able to kind of manage it to that extent. But the cataplexy, when it happens, it it's very rapid um and they have very little control over it. It still requires such a it's such a change to life or such an impact on life that it that it must have for people. I mean, even even if there's a degree of control of being able to say, okay, I I can get myself to somewhere that I can sleep. It it does. And and one of the sad things is that the time between developing symptoms and getting a diagnosis on average is uh about a decade. So people live with us for a very, very long time. Interestingly, for a lot of patients, the cataplexy is the more problematic aspect of the illness. Um, because sleepiness is something that one can manage. You can have naps. You do know it's predictable. You know that you're going to feel sleepy, and so you could say, Well, I, you know, I'm I'm not able to drive, but I know if I take a nap, I'll be able to then get on the bus and get to my destination before I feel sleepy again. The cataplexy is so unpredictable. You you could be crossing a road and you see someone you haven't seen in a long time and you have an attack in the middle of the road. It makes people afraid to uh to swim, because what happens if they have an attack when they're swimming? And people will often learn to rein in their their positive emotion because they know that that triggers uh uh uh triggers an episode. So they they don't like to laugh. They try and distract themselves when their friends are joking. And so it's an em it's very often that cataplexy which is the most limiting uh symptom. Gosh, that's so they're really having to restrict the range of of emotion that they can feel to to try to prevent to try to prevent an attack. Yeah. Oh yeah. That's really and I mean I imagine that can only ever be partially effective in any case, but that still again must be such a such a restriction on life. Yeah. Yeah. In terms of the idiopathic hypersomnia, so that sounds like a quite a different kettle of fish from from from what you've talked about, and quite tricky to to manage potentially, and again, maybe quite debilitating for people. It's incredibly debilitating. Um, you know, people with idiopathic hypersomnia will often wake up just feeling unbelievably sleepy, and they have this thing called sleep inertia where they just cannot wake up and you know the family come in eight times and shake them and the alarm goes off, and it just doesn't, you know, they really just cannot drag themselves out of the bottom of the swamp of sleepiness into wakefulness. And when they do manage to get out of bed, it's a couple of hours getting their brain to really start ticking over and functioning. They just feel sleepy almost the whole day. Sometimes they'll have a couple of hours, often in the later afternoon, early evening, where they feel a bit more functional and then the sleepiness kicks in again. Um, and they're often sleeping 10, 11, 12 hours at night, which means that it leaves them very little time in the day to get anything done. Because they they don't have these REM phenomena that you get with narcolepsy, the mainstay of treatment is stimulant medication. Uh, but as I say, in my experience, it's often one needs higher doses, and the results are not always as as good as with narcolepsy. Do we have a a sense for what causes the hypersomnia in in those people? No, we really don't. Um we know there's an uh there is an association with depression, but we don't know which way that round that goes. And I think my experience with patients is they often feel that the hypersomnia causes depression rather than depression causing the hypersomnia. But you know, it's not a psychiatric thing. Uh there's no question, it's a genuine physiological um sleepiness, and we can measure that really, you know, uh objectively in the lab, that they are sleeping very long. Their sleep is too consolidated. They don't have they don't have the normal awakenings that we would see at night. Um, and if left in the lab during the day, they will fall asleep at the drop of a hat. Hmm. Okay. And then you've touched on uh the the disorders of the circadian rhythm. People's timing of sleep is knocked off in some way. Well what happens, what happens there? So circadian rhythm disorders where your internal body clock is out of sync with the outside world. And um, this could be a stable misalignment. Um so, for example, the most common one we see is a delayed sleep-wake phase disorder where the person's body clock is running behind the outside world. And as a result, they naturally want to fall asleep really late, two, three, four in the morning. They naturally want to wake up late, uh, late morning, early afternoon if they're left to their own devices. Typically, this starts in adolescence. Uh, people will feel their worst in the morning and their best late at night when everyone else, you know, they feel most alert when everyone else in the house is getting ready for bed. It could be an unstable misalignments and something called a non-24 hour sleep wake disorder. And this is more common in people who are blind, but not exclusively. And um, this is where our internal body clock naturally tends to run at slightly longer than 24 hours, which means that if it's not anchored repeatedly, it will drift later and later and later, and the person's their sleep rotates around the clock. And sometimes the disorder is uh that you have a completely normal body clock, but the demands on it are unreasonable or don't match up. So uh jet lag where you take a normal body clock and move it to a different time zone, so they're misaligned, or shift work disorder where you um uh you are expecting a person to be aw alert and active when their body expects them to be asleep, and then uh having to be trying to sleep at a time when their body expects to be awake and they just can't get sufficient sleep as a result. So again, there's quite a range of different things that can that can occur or or sort of go go wrong. Yeah. Um we have this delayed body clock, uh, we have an opposite is the advanced body clock, uh, although that's much rarer. Um, we've got the non-24 hour, and you also get some conditions, particularly in neurodegenerative conditions and dementia, where you have a complete absence of a body clock. Um, and therefore the person's as likely to be awake at night as they are in the day. There's also the theory that seasonal affective disorder, um, where people get sort of this winter depression, uh, may be a circadian rhythm disorder. Um, and what's thought might be happening here is that the person's in the winter your the person's body clock drifts late, but their sleep stays at the normal time. And now there's a mismatch between the sleep time and the body clock, um, and that this might be what drives uh the seasonal effective disorder. And it's one of the reasons why it can be treated using light, because light using light in the morning helps to advance the body clock, so it pushes it back into phase with the sleep. Hmm. Why do why does this relationship perhaps exist? Why do we think that the the mismatch between sleep body clock uh maybe has such a strong impact on mood? Our circadian rhythm controls a whole range of things. It controls when we're asleep, when we're awake, um, our metabolic rate, our body temperature, uh, immune function, um, endocrine functions, and so on. Our alertness is at its lowest, usually around about five in the morning, four or five in the morning for most people. That's an average, it varies. Yeah, yeah. Some people it's earlier, some it's later. And with that low alertness, that low metabolic rate, the low body temperature, also tends to come a lowish mood. And you know, if you think about when you do all uh all nighters on doing an on-call, you often don't you don't feel particularly happy at five in the morning. Now, most of us don't experience that because at five in the morning we're fast asleep. So one possibility may be that if your body clock is drifting late relative to your sleep, that minimum in your alertness, in your metabolic rate, um, that low period of low mood is now occurring during wakefulness. It's occurring in the morning after you've woken up. And if you're then exposed to this sluggishness, uh lethargy, low mood day after day after day, that this then precipitates the depression. Fascinating. Okay. So it's this is something that is generally occurring normally, but at a time where we're not awake. But by pushing it into a point where we are awake, it now is our experience. Exactly. Yeah. And is now therefore the the the colour of of what we feel. Yeah. And you you touched on this with in terms of the dysregulation that can happen in dementias. And immediately the the question that sprung to my mind is around delirium as well. I mean, something that we see in hospitals so commonly, where people for a multitude of reasons end up having uh sort of acting in a very strange way. It's much more common uh in people who are older, but can happen in in young people as well. People have hallucinations and become quite paranoid. But also that's some sleep seems to be a big problem in in those cases, or or there's a real variation, you know, people's behavior might be particularly different and difficult in the say later part of the day. Is is this to do with circadian rhythms as well, or is it or is there something unrelated? I'm sure it's multifactorial and there are other things involved, but the circadian rhythm, I think, does play an important role here. And if your overall level of alertness is impaired during the night, it is going to make it harder then for the person's for the person's brain to kind of make sense of what's going on around them. It's going to increase their confusion and their anxiety. Um, and certainly there is some evidence that by really kind of giving good time cues to help anchor the circadian rhythm uh when patients are in hospital, that this can reduce the incidence of uh delirium. The other thing that uh I've always wondered about um very often in uh in old adults with dementia, particularly vascular dementia, you get this thing called sundowning where they become more agitated at night. And I do suspect that a proportion of those patients are are experiencing restless legs, which is this discomfort in the legs that makes you compels you to move, which occurs um, which occurs at night. It's it's time dependent. It doesn't tend to strike during the day, it tends to strike at night time. Uh and because it is such a hard sensation to describe, even if you're fully cognitively intact, it's very hard to describe. For someone who's not uh fully cognitively intact, it's even more difficult. And so I do wonder if sometimes when we see the sundowning or we see this increased agitation at night, could this in fact be restless legs? And certainly that population have a very high risk for a restless leg. So um it is something to consider. What is it that restless legs feel like when people describe it? You'll hear lots of words like kind of, it sort of feels like it's hard to describe, but um sometimes I'll describe it as being feeling like an electric current in their muscles or water or worms in the muscles or feeling that the leg is hollow or empty or somehow very heavy. Um it is really difficult to describe. And what people will typically say is um they can show you the area where they feel it, but really struggle to describe what it feels like. But it's something which is very clearly worse at night, uh, is worse at rest and is temporarily relieved by movement. And because it's worse at night and worse at rest, it's gonna hit when you're lying in bed at night trying to sleep. And if the only way to get rid of the sensation is to move, it makes it very difficult to fall asleep. And as a result, this very often will present as sleep-onset insomnia. Um it's surprisingly rare for people with restless legs to say, I have restless legs. What they say is I can't get to sleep. Um and it's only if we specifically ask about restless legs that we'll get that history. And it's something that we really need to look out for in people who are restrictive eaters because dietary deficiencies can affect people who've got um inflammatory gut disorders or uh disorders of absorption. Uh, it can be caused by any nerve damage. So more common in people's diabetes, with back problems. It can run in families, which I think is another reason why often it's not reported, is because, well, if my mom and my sisters have it, I assume it must be normal. Iron deficiency is a big driver, but also really importantly, is a lot of medications can cause it, and particularly psychiatric medications like antidepressants. So it is something that unfortunately is sometimes caused by the doctor rather than being uh dietary deficiency or or or nerve damage. And I guess the treatments will then really vary depending on what the suspicion about the underlying cause is. Yeah, if we you know see, for example, a really you know low iron or a low vitamin D, we would correct that first. There are some medication treatments available as well. Um they don't uh come problem-free, but they can be very effective. And we will we would select uh a medication that's appropriate to that particular patient. And you know, generally, again, it's something that is very treatable. Um and it's I think the difficulty is that it's very rarely correctly diagnosed. So one study, for example, found that uh physicians correctly diagnosed restless legs in uh around 10% of cases. Wow. Which is pretty uh pretty striking. So um it it is very often misinterpreted as being an insomnia and the the treatment is completely different. And it sounds like it's worth being suspicious of it, you know, certainly with insomnia, but even perhaps in in cases where it's more tangential uh to insomnia, like somebody with really restless or agitated behavior in the later part of the day who has a dementia who may not be able to fully describe the experience. Yeah. And the other people you really want to look for it in is people with ADHD and often in kids with AD. Um it's it's often misinterpreted or misdiagnosed as growing pains. And restless legs is significantly more common in people with ADHD. Also, incidentally, uh, that delayed sleep wake phase disorder where the body clock's delayed relative to the outside world is markedly more common in people with ADHD. So those are two things that we should always be thinking about in ADHD patients. And how, I mean, coming back to the to the body clock disorders and sort of the delayed body clock disorders, well, how do you manage them? Again, uh, it sounds like it may depend on when it's arising. So the main treatment is melatonin and light. With a delayed sleepwake phase disorder, we use very low doses of melatonin in the evening and light in the morning to advance the body clothing. Similar treatment for the non-24-hour disorder, melatonin's used uh also for um jet lag. For the other circadian rhythm disorders, there is really very little or no evidence-based treatment at all. And so it does come down to looking at the individual and trying to work out with their particular problem, their profession, when they tend to drive, what their shift pattern is like. Things, yeah, all of those things need to be taken into account when thinking about the way of managing it. And it sounds like shift work um is again something that, well, not necessarily that the doctor's caused, but that society's caused that can really, really cause sort of wreck havoc with with people's sleep. It really can. And um there is no good way to do shift work. Uh, there are less um less bad ways of doing It but there's no good way to do it. People often ask, well, can I adjust my body clock? Can I adjust my circadian rhythm for my week of nights or whatever? And the answer is no, we can't adjust it that quickly. You can shift your body clock, but it takes a long time. It can take weeks to shift your body clock fully into a different phase. Um, and you know, so the person will just start adapting to night work, and when just as they're starting to adapt, they'll switch back to days. So you're always playing catch-up with um with shift work. The one thing that we do really advocate though is to if you're doing shifts, for example, in earlies, late and nights, that you rotate the shifts later rather than earlier. So you go from an early to a late to a night to a day off to an early to a late to a night for two reasons. Firstly, your body clock, as we said, tends to run slightly longer than 24 hours. So it finds it a bit easier to delay than it does to advance. The second reason is if if, for example, you go from a late to an early, you just don't have enough time in the night to get sufficient sleep before you have to wake up for your next shift. So ensuring that you're always rotating your shifts later rather than earlier at least gives you enough time to try and get enough sleep. Mm-hmm. Mm-hmm. And it sounds like similar to maybe some of the principles of managing jet lag? Jet lag, there is evidence for the use of melatonin. Okay. So uh particularly if you um if you travel east, it's often harder to adapt to the new time zone because you have plans. Um so there is evidence for the use of melatonin, which you take at bedtime at your destination for a few nights on landing. There are some very complicated regimes that you can use with light, avoiding light at certain times of day and then exposing yourself to light at other times of day. But for the vast majority of people, these are just not practical. Um, it's the kind of thing that you you know, perhaps sports teams who really need to perform at their peak might try and utilize. But for your average traveller, you know, if you're flying to New York, you don't want to hide indoors at certain times of the day and get outdoors at the crack of dawn to you know to shift your body clock. So they they're not very practical. Mm-hmm. Okay. But the the sort of the football world cup coming up in the United States this summer, uh, and sort of in the in North America, they they may be wanting to look at this to enhance their or improve their performance when they when they get there. Yeah. Even in the United States itself, it's been shown that the jet lag of crossing three time zones can affect sports performance. Um, and it's an even bigger issue in other sports. So in the southern hemisphere where they have the rugby championship, where players are playing in uh South Africa, Australia, New Zealand, and Argentina, you're crossing a lot of time zones and it it must have an effect on performance. And one of the things that some sports teams try and do is actually to remain on their home country time as long as they can when they get to their destination. Uh just not to not even try and adapt to the new time zone, knowing that there's not enough time to do that before the match. Gosh, because yeah, that's a wild amount of time zone crossing for the for the Rugby World Cup that they're doing. And from everything that you've talked about, it's you know, in terms of energy, in terms of your metabolism, your immune function, etc., it sounds like that disruption to your to your sleep and body clock really can't be helpful. It's interesting though that studies looking at elite sports people uh often find that they're not great sleepers, that they're quite poor sleepers often. And you know, this is really interesting because we we're always taught that you know sleep is so essential for physical recovery and how and when one has insomnia, one of the great fears is I'm not my body's going to suffer because I'm not able to recover because I'm not getting enough sleep. And yet you when you look at people who are performing at the absolute peak of human physiological capacity, they're often really poor sleepers. And that suggests that either sleep is not as important for physical repair as we thought, or that you don't need a lot of sleep to get that physical repair function, to get to get that out the way. Um and and I think that that can be quite a reassuring message, really. It links to what I think what you would have been saying last time about some of the work with people with insomnia is around actually normalizing and giving them a realistic expectation of what good sleep, so to speak, is truly like. I mean, yeah, because that's fascinating. But if and and when you say sports people tend to be poor sleepers, is it about the amount that they're they're not actually sleeping for lots and lots of hours? It's they tend to be relatively short sleepers and they tend to have uh quite a lot of sleep fragmentation. And in a way, it's not surprising. They, you know, they're in a high pressure pressure profession. There's a lot of travel, there's a lot of staying in um in different hotels every week. There's often going to be you know physical pain and niggles and discomfort. So, you know, it it uh it's not at all surprising that they're not the world's best sleepers. So uh a helpful way to reassure, I think, people that it's it doesn't have to be the end of the world, certainly to have the odd nights bad sleep. Yeah. Hugh, we've again sort of done a real whirlwind tour of of so much of sleep medicine and so much of your work. Are there any any points that I guess we've missed that that you'd want to point out to our listeners? I guess the one thing we haven't had a chance to talk about is uh obstructive sleep apnea. Um and it's worth just mentioning that um, as we said, this is this condition where your throat closes in the night. And the symptoms typically are someone usually people will snore, not always, but most of the time people will snore. Uh often their snoring is in a bit of a crescendo pattern, getting louder and louder and louder and then stopping. So there'll be these observed pauses in breathing, or the person might occasionally wake up feeling that they're choking. It uh increases your urine production. So people with this condition will go to the bathroom more often at night. That can sometimes be a clue. Night sweats, morning headache, things to look out for. There are people who are skinny as rakes who have obstructive sleep apnea. So if one does have these symptoms, it is worth getting it checked. Um, it used to be a really big deal to go and get a sleep apnea check. Now it can be done with a really simple home study. And from a psychiatric perspective, there is a very close association, again, between obstructive sleep apnea and depression. Uh, there's an enormous overlap uh in the symptomology. And so it has been uh has been found in one study that actually people with sleep apnea may present first to a psychiatrist because you feel low, tired, irritable, can't concentrate, can't remember things. And that you know, sounds for all the world like depression. And uh it is also a sleep disorder with with very significant physical health consequences. It affects uh your your blood sugar, your cardiovascular health. Um, we now know that it's a risk factor for dementia. So we used to say, well, you know, snoring is okay, and as long as you feel okay during the day, it's all right. And I think what we're now really thinking is that there is no such thing as normal snoring or normal, you know, just a little bit of sleep apnea. If one has these symptoms, it's worth getting them checked. And it doesn't always need treatment. If it is mild, you may not need it treated. But we have a wider range of treatments now than we've ever had before. So uh again, it's easy now to diagnose. We've got uh more treatments than we've had in the past, and it's you know always something to be on the lookout for. It sounds like a really important part of, you know, especially if people coming to psychiatrists with tiredness, poor sleep to actually inquire as to for the presence of snoring or for for the daytime sleepiness to to try to identify this condition. Yeah. Yeah. Um and I, you know, it's again, I think we we we're certainly seeing more people coming forward saying that they're concerned about it. When I first started in sleep medicine, it was almost always the bed partner who brought the patient to the clinic. Um, and the complaint was that they're snoring and that they are falling asleep at family dinners. Whereas now people are more aware of it and saying, I'm concerned, I may have sleep apnea. So there's certainly been an improvement in uh in the pickup rate and an improvement in public understanding, but there's still more that needs to be done. And when you say treatment is really available, I mean the the vision that I have is of the the sort of the big masks that change your airway pressure. Is is this the mainstay still, or is that quite out am I quite out of date? It's still the gold standard. Um the what we call or now we used to be called CPAP, continuous positive airway pressure. We now use something more called APEP, autoset positive airway pressure, which is a machine that adjusts the pressure throughout the night because some people might need a high pressure on their back, but a much lower pressure when they're lying on their side, for example. And these machines are often really adaptable and more comfortable, they're much quieter than they used to be. There's a big range of masks one can use, some that go over the nose and mouth, some that just go over the nose. For milder obstructive sleep apnea, we can use a special jawguard called a mandibular advancement splint that pulls your lower jaw forward. Uh, you just wear it during the night and it opens up your airway. Again, for milder sleep apnea, there are some exercises one can do. For example, classical singing training, um, or even uh a paper in the BMJ from a few years ago showed that playing the degeridoo uh on a regular basis can improve sleep apnea. And now there's also um these what we call hyperglossal nerve stimulators. This is like a pacemaker that's implanted in the person, and it's got an electrode that sits on the hyperglossal nerve, which pushes your tongue, tells your tongue to move forward, and as you breathe in, it sends a signal to the nerve. The nerve then pushes your tongue forward and that helps to open up your airway. Um, this is very, very new in the UK. It has been used uh for some time abroad, but it is something that's becoming uh more available over time. Fantastic. That sounds uh yeah, I have definitely was out of date, so I'm very glad uh to know. And I mean, especially just the idea that machines can be quieter, that masks can be smaller, I feel like that m will certainly push more people into seeking treatment, uh, into knowing that there's potentially not too disruptive a solution. With many things in medicine, we often have to, and you know, as a psychiatrist, I'm I'm very used to this idea that if I start treating you today, maybe in four to six weeks, you might come back and tell me that you're feeling better. When someone's got significant sleep apnea and you start them on this APAP, they come back the next day and go, Oh my gosh, I haven't felt this good in years. And that's a really that that's a really satisfying thing to uh to see. I'm very glad that uh we have that note um for for people to be aware of and also for their doctors to be aware and to look out for. Hugh, thank you so much for taking us through all of these different things. We uh I'm sure there's gonna be a lot of questions that arise from people. Um and uh I imagine people may well reach out to you um if you're happy to be contacted or sort of may well sort of look at look at some of your work online as well, which we can link people to. Please, please do get in touch. We, you know, uh sleep medicine is so new and it's uh there's there's so few places available or you know, have been so few places available to to treat it. So we're always keen to get the message out there and um make more people aware of uh how important this one third of our life that we spend sleeping really is. Absolutely. Thank you so much. Thank you for your time.