Gresham College Lectures

Sleep and Mental Health

March 28, 2023 Gresham College
Gresham College Lectures
Sleep and Mental Health
Show Notes Transcript

In recent years, the links between sleep and mental health have been slowly unravelled. We are beginning to understand that not only does mental health impact sleep, but also that poor sleep has important consequences on our psychology.

This lecture explores this complex relationship, and highlights the importance of sleep as a major factor in our mental wellbeing. The lecture covers strategies to manage disturbed sleep, and touches on other disorders such as nightmares and night eating syndrome.


A lecture by Guy Leschziner recorded on 13 March 2023 at Barnard's Inn Hall, London.

The transcript and downloadable versions of the lecture are available from the Gresham College website: https://www.gresham.ac.uk/watch-now/sleep-health

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(swooshes)- I think everybody will be very familiar with this feeling, the feeling of when you've had a very bad night's sleep and you feel tired, obviously, but you also feel slightly grumpy, a little bit more irritable. So it's very intuitive to imagine that sleep may affect our mental health at least on a short term basis, on those nights when you've had a particularly bad night's sleep. But when it comes to sleep issues and mental health, we know that both of these problems are very common. So from a sleep perspective, about 20 to 30% of adults in any one year will experience insomnia. About 10% of the adult population will experience chronic insomnia. And there are a whole range of other sleep disorders that are really surprisingly common, conditions like obstructive sleep apnea, which is where snoring results in obstruction of the airway. That's thought to affect up to about 25% of adult men and a slightly smaller proportion of adult women as well. But when you look at the presence of sleep disorders and mental health, the co-occurrence, so seeing both sleep issues and mental health issues in the same individuals is much higher than by chance alone. And when you look at, for example, people who have sleep disorders and their rates of mental health issues, they're very high indeed. So in individuals with insomnia, the concurrent diagnosis of a mental health disorder is about 40%. If you look at people who are excessively sleepy, it's probably even higher, it's of the order of getting close to 50% and that's compared to a rate of about 15% in individuals who have normal sleep. So really very much out of proportion. We also know that in insomnia, the presence of a mental health diagnosis or indeed a past diagnosis of a psychiatric disorder is very high indeed. But when you look at those individuals in a little bit more detail, what you typically see is that when it comes to associations between sleep disorders and mood, the sleep disorder is often present before or with the onset of the mood disorder, whereas with anxiety it's slightly different. The sleep disorder often starts alongside the onset of anxiety or shortly thereafter, and I'll come back to that shortly. So in the past, this association between sleep issues and mental health disorders, particularly by the psychiatric body, has very much been the case that sleep disturbance is a secondary phenomenon of mental health issues that essentially sleep disturbance is a symptom or is a consequence of mental health issues, i.e, it's the depression that's causing the sleep issue, it's the anxiety that's causing the sleep issue. And the commonly held belief until recently has been very much that if you address the psychiatric disorder, you will improve sleep. So this kind of picture whereby it's the psychiatric disorder that results in the sleep disorder and it's this psychiatric disorder that you need to deal with in order to address the sleep. But actually what we are beginning to understand is that this is a gross over oversimplification of the relationship between psychiatry and sleep medicine. And that actually this is a bidirectional relationship so that psychiatric disorders give rise to sleep disorders and also vice versa. And what I'm going to be discussing today is some of the evidence that shows this bidirectional relationship, that shows the links between the two. So why should sleep disturbance be causative of mental health issues? Well, if you look at acute sleep deprivation, so this is only sleep deprivation over the course of a single night or over a few nights, then we know that even short-term sleep disruption or sleep deprivation can result in a number of different psychological and physiological effects that might have some bearing on mental health. So we know that as soon as you sleep deprive somebody, their ability to regulate their emotions lessens, they begin to interpret relatively neutral stimuli in very negative terms, their perception of pain increases. So there have been a variety of studies that are usually done on German or Canadian medical students whereby they sleep deprive them and give them electric shocks and see what threshold they yell at. And it's very clear that a single night of sleep deprivation dramatically alters your pain threshold, that sleep deprivation, acute sleep deprivation again, results in significant problems in inhibiting responses, so essentially frontal lobe dysfunction. And in fact there are a wide array of cognitive functions that suffer as a result of a single night of sleep deprivation. There was a famous study done about 20 years ago where they looked at the effects of sleep deprivation and compared those effects both from a cognitive perspective and also from a sleepiness perspective in relation to alcohol. And what they found was that even two hours of sleep deprivation is the equivalent in terms of cognitive dysfunction or in terms of sleepiness of two to three units of alcohol, so really quite significant indeed. And then there are a range of physiological effects. We know that acute sleep deprivation results in abnormalities of endocrine function. So your hormones with increases in cortisol increases in adrenaline, and these all have some knock on consequences on neurological or psychiatric functioning, it affects your immune system and it also affects an aspect of your nervous system called the autonomic nervous system, which is the part of the nervous system that's responsible for unconscious physiological processes within the body For example, your gut, sweating, regulation of blood pressure or heart rate. And these can actually have knock-on consequences on psychological factors. So for example, if you increase heart rate using a drug, then that can increase people's anxiety. And there have been some very elegant models done in mice, for example, where they've increased heart rate using a variety of very fancy genetic techniques called optogenetics, where they switch genes on and off using light. And what they can demonstrate is that if you solely increase heart rate in a mouse, you see changes within their brain that are very strongly paralleling changes that are indicative of anxiety, for example. So we have this constant feedback loop whereby physiological signals are integrated into our brain and regulate our emotions. So I'm going to start off by talking about anxiety first off. So for many people in this room, the relationship between anxiety and sleep is very self-evident. You know, when you are anxious about something, you are going to sleep more poorly. And I think that that is a very common human experience. It doesn't necessarily mean that you have a clinical disorder, but that is part and parcel of anxiety and of course, anxiety is about perceived threats. It's about being on high alert for threat within your environment, it's about something called hypervigilance. So being on alert for those dangers and being in a constant state of flight, fright or fight. So this high alert whereby you are monitoring your environment and that in itself is quite an alerting phenomenon when it comes to sleep because of course, insomnia is also a hyper-arousal state. Many of the experiences of insomnia are such that people will say, well I feel on very high alert, I can't switch my mind off. I'm finding it difficult to go to sleep. And indeed many people within insomnia will experience this phenomenon of hyperarousal even during the day. So many people who will say that they sleep very badly will feel very tired during the day, but they will say that they feel on high alert, they feel jittery, they feel within that constant state of flight, fright or fight. And in fact, when you look at the genetic contributions to anxiety and insomnia, there is almost in an entire overlap in the genes that have been implicated in anxiety and insomnia. So both in terms of a physiological and psychological state, there are huge parallels but in genetic terms, these are very similar as well. And it's perhaps not surprising that about 75% of people with anxiety also report significant sleep disturbance. So what do we know about the role of sleep in anxiety? Well this is a rather interesting study, goes back to giving medical students electric shocks. So this study was done whereby they presented a number of normal individuals with these different faces. So these are all computer generated faces that have been altered very slightly. And what they did was they gave these individuals a learning task, whereby every time they saw one of these three faces, they gave them an electric shock, in order to generate a conditioned response. So when they saw that face, then it induced a perception of threat or an expectation of harm. And after that learning task, they then randomized them to sleeping a good night's sleep or not sleeping at all. And what they very clearly demonstrated is that in those individuals who had not slept at all, they generated physiological changes consistent with threat, consistent with anxiety, even when they were shown the other faces, not just the face that they'd learned the task to. So demonstrating that actually a single night of sleep deprivation really does fundamentally alter your level of alertness for threat, your level of monitoring for threat, and your perception of threat as well. And indeed when you sleep deprive individuals and you look at their brains, what you see is you see very similar patterns of changes in activity to those seen in individuals with anxiety. So we see a dramatic increase in areas of the brain that are involved in a system called the limbic system, which is very important for emotional processing and emotional memory. In particular an area of the brain called the amygdala, which is essentially the fear processing center of the brain and also another part of the limbic system called the cingulate gyrus. And you see impaired frontal activity and these are patterns that you see in individuals with anxiety as well. So what do we know about the role of sleep in generating anxiety? Well this is a really interesting study from about 2005, where they looked at individuals who had persisting sleep issues in childhood and what they demonstrated was that those children who had those persistent sleep issues had an increase of about 60% in the likelihood of developing anxiety in adulthood. So really suggesting that there is some sort of causative relationship between the presence of sleep and subsequent development of anxiety. Now that of course is not the only explanation because it could be argued that if you have an underlying genetic predisposition and as I've already said, there is a shared genetic predisposition to both insomnia and anxiety, it may be that that anxiety comes to the fore in later life but certainly is a little hint that actually sleep disturbance may give rise to anxiety later on. I'm going to talk about a very specific type of anxiety, so post-traumatic stress disorder. It's a very specific anxiety state that results in marked hyperarousal, so that fright, flight or fight response, that in contrast to generalized anxiety is often triggered by particular triggers that are a reminder of a particular psychological or physically traumatic event. And hallmarks of PTSD include this hyperarousal state, but also flashbacks that are often precipitated by triggers, sleep disturbance is incredibly common. So about 90% of individuals with PTSD experience sleep issues and also trauma related nightmares. So often very vivid emotionally charged nightmares that are often either linked or directly the traumatic experience that has triggered the PTSD. So when we look at individuals with post traumatic stress disorder, we know that one of the strongest factors for predicting whether or not somebody is going to develop PTSD after a traumatic event is poor sleep prior to or indeed after that trauma. So certainly there is something about sleep deprivation that seems to put people at risk of developing PTSD. Now why should that be the case? Well there is increasing evidence from other areas of research that suggest that REM sleep, in particular, rapid eye movement sleep, so this is the stage of sleep that we most associate with dreams, particularly dreams of a narrative structure, it has a very important role in cleansing emotions from memories. Now obviously from an evolutionary perspective, it's really important that if an episode is linked to very strong emotion, for us to remember that from an evolutionary and a survival perspective. But what's not very useful is to maintain that degree of emotional involvement with that memory. You need to try and reduce the emotional component of that memory over time. And so one of the observations has been that REM sleep seems to be particularly associated in taking the emotion that's associated with the particular memory, and REM sleep is part of that desensitization, that reduction in the emotional component to that memory over time. And this has really led to the view that actually REM sleep may have a function as what has been termed overnight therapy, that actually it helps the emotional processing of a particularly traumatic event. And if you imagine that individuals in PTSD have the same nightmare but that nightmare is associated with a very strong emotional charge, an emotional charge that's strong enough to wake you up, then that process is never completed. And that perhaps is one of the theories as to why PTSD and those symptoms associated with it can continue for as long as they do. And in fact often those nightmares associated with PTSD are the last features of PTSD to go as it resolves. So we know that actually there are some standard psychological therapies and actually this treatment called cognitive behavioral therapy for insomnia is really the gold standard psychological treatment for insomnia. And I'm going to go on and describe that in a bit more detail later, can very clearly treat PTSD symptoms. So simply by treating sleep using a non-drug based technique, you can directly address PTSD. And indeed when one looks at anxiety in general, CBT for anxiety also causes a moderate improvement of sleep. So once again, very clear evidence of this bidirectional relationship between anxiety and PTSD and sleep disturbance, that one begets the other. Well what about depression? Well, sleep disturbance in depression is extremely common. About 85% of people with depression have significant insomnia. About 50% are excessively sleepy and about 30% of people with depression have both. And in fact, sleep disturbance is so common that it forms part of the standard diagnostic criteria for depression, particularly patterns of sleep like early morning waking is very much seen as a biological symptom of depression. And the reason why understanding the relationship between depression and sleep, why it's so important is we're actually quite poor generally at treating depression. And actually if we are to find treating sleep is as important as treating the mood disturbance in order to result in an overall improvement, then this might dramatically also improve our success of treating these kinds of mental health disorders. So what do we know about this link? Well we know that if you have insomnia, it doubles or even triples the risk of developing depression later on. So there is something about insomnia that seems to predispose to depression. We know that in children in particular actually there are changes in our biological clock that put us at risk of depression. So if you have something called delayed sleep phase, so this is if you are a night owl, if your biological clock is linked to going to sleep late and waking up late, that increases your risk of depression in childhood. And insomnia is a really important and consistent risk factor for suicidal ideation and suicide attempts. So if you in clinic see somebody who is depressed and has insomnia as well, that sets off alarm bells because they're at much higher risk than average. And one of the other interesting observations is that when people have depression and they remit, so they are successfully treated, their insomnia frequently disappears, it frequently continues as well, but it's much more likely for insomnia to continue even in depression that is ongoing, suggesting that they are two separate entities but that clearly insomnia increases the risk of not getting better from your depression. So when we look in the general population, and this is looking for depressive symptoms in the general population, what we see is that in individuals who've got insomnia, if we treat insomnia usually with this treatment called CBTi, cognitive behavioral therapy for insomnia, that causes quite a significant reduction in depressive symptoms. And in one randomized control trial that was done relatively recently where they gave people, some groups CBTi, the other group they gave sleep hygiene education. Sleep hygiene is this terrible term that we use all the time. Essentially what it describes is advice regarding behaviors that improve your sleep, simple things like avoiding caffeine at night, like not exercising late at night, like making sure that your bedroom is dark and quiet, really rather common sense, but it's often used as a treatment for sleep disturbance, that is not really a treatment. What they demonstrated is that actually if you give people CBTi, as opposed to sleep hygiene education, there is a clear benefit in terms of treating depressive symptoms associated with insomnia. And the other really quite striking feature is that if you treat insomnia successfully, then you reduce the likelihood of a depressive episode over the next year. So that's really suggesting that actually improving insomnia reduces the risk of developing depression. Now the reason why it's up to a year is because that's the longest study that's been done so far, but it may be that actually treating insomnia may have a dramatic improvement in the likelihood of developing insomnia later on in life for many years to come. So what about in people who are clinically depressed? Actually, very similar findings. When you give people CBTi versus standard sleep advice, this concept of sleep hygiene, on top of standard treatment for depression like antidepressant drugs or psychological interventions for depression, you increase the likelihood of remission. So it's worth saying that CBTi is a very simple treatment that doesn't involve giving people any drugs, it doesn't involve giving people medications that are potentially side effect causing and that might result in withdrawal effects. So this is a really simple intervention that can dramatically increase the likelihood of recovery from conditions like depression. And if you look at other comparators, so another study looked at the combination of antidepressant drugs and sleep hygiene advice versus this CBTi plus a placebo instead of an antidepressant, these had very similar impacts on depression. So really suggesting that actually a sleep intervention may be as good as starting people on antidepressants or at least some people on antidepressants. And actually when you look at psychologically-based interventions directed at insomnia versus psychological interventions directed at depression, they seem to have similar reductions in depressive symptoms. So once again highlighting the fact that ignoring sleep in individuals who are depressed is potentially not doing them any favors. And there are yet more studies that show that if you improve sleep early on in the treatment of somebody with depression, you are likely to increase remission of that depression, that poorer sleep at baseline really does predict a more difficult course, people being more refractory to standard treatments. And going back to this issue of children who have a delayed phase at being at increased risk of depression, in adults, we also see that this is a very important factor that a delayed sleep phase, so being a night owl, tends to put you at risk of a higher severity of depression, more suicidal ideation. And the reason why this is important is because there are some very simple treatments like light therapy or melatonin that can be very useful in driving people's body clocks forward or back. And I'm going to come back to that in a little while. This is the the final mental health condition that I'm going to be discussing, the most serious of the mental health conditions that we see, schizophrenia, and the view that sleep may have an important role in schizophrenia has come from a number of observations. The first is that many people with schizophrenia, in fact, the vast majority of people with schizophrenia will complain of sleep disturbance. The second observation is that actually if you improve sleep, it tends to improve delusions that are associated with psychotic episodes. And the other feature is that actually schizophrenia often results in marked sleep disturbance that is rather peculiar in other walks of life. So this is a plot of an actograph, so this is a little watch like device that monitors movement and it uses movement as a proxy marker of sleep. And what you can see here is that midnight is on the far left and you can see there are two days in each line. And what you can see is that whilst the majority of movement does happen during the day, the circadian rhythm, that standard pattern of going to sleep at 10 or midnight and waking up between six and eight has largely gone and sleep periods occur during the day, they occur during the night, there is a breakdown of the natural circadian rhythm. And this is something called non-24 hour, sorry, irregular sleep-wake disorder. And this is something that is really very peculiar to schizophrenia, we don't see it very often in other conditions. So we know that there are very clear associations between sleep issues and psychosis in that if you have sleep issues, again, as with depression, it seems to double the odds of having a psychotic experience and that the severity of the insomnia that these individuals have correlates very closely with psychotic symptoms like paranoia or thought disorganization. And in fact one of the really interesting observations which is generating a lot of research at the moment is that about 75% of people with schizophrenia will complain of significant sleep disturbance many days or even weeks before they begin to develop psychotic symptoms. Now this is from a therapeutic perspective really interesting because if we can track people's sleep and we can identify a deterioration in their sleep, then we can actually predict that they might be going on to have psychotic episodes and may actually be able to pre-treat them to stop their psychosis getting as bad as it is. And in fact, if you look at individuals who have their first episode of psychosis, about 80% have a diagnosable sleep disorder. In fact, the average number of different types of sleep disorder in individuals who develop their first psychotic experience is three different types of sleep disorders. So it is really very suggestive of the fact that actually sleep and psychosis are very closely linked. And again, as with the depression, sleep and circadian problems really do predict a poor prognosis in these individuals. So does sleep intervention help? Well actually this is one of the areas of research that really does need quite a lot more work because in patients with psychosis we have very limited data. We know that actually CBTi does help these individuals and it causes large improvements in sleep and there's some preliminary data that it also improves their psychotic experiences. But when you take normal individuals,, and it's worth saying that normal individuals will often experience psychotic like symptoms, then if you improve sleep in normal individuals, you reduce the frequency of reporting of psychotic like experiences and vice versa. If you reduce sleep to about four hours, there is a significant increase in these symptoms. So once again showing a direct correlation between sleep and psychotic illness. So what about other settings? Well, this is more in my world, in the neurological world. So we know that actually sleep disturbance or sleep disturbance as a result of psychiatric or psychological factors can actually affect a range of other conditions. So this is to illustrate sleep walking. We know that actually stress and anxiety are very common triggers for sleepwalking because essentially what happens when you are stressed, when you're anxious, your sleep is rather fragmented, it's disrupted. And actually in sleepwalking what we know is happening is that any factor that disrupts your sleep, particularly the deeper stages of your sleep, can result in part of the brain waking up parts of the brain that are responsible for movement, for emotion, whereas the rest of the brain remains asleep. And if you have stress or anxiety that is fragmenting your sleep, it puts you much more at risk of having these kinds of episodes. This is a picture by Henry Fuseli, who's an Anglo Swiss painter, it's called the Nightmare. Actually from my perspective, rather than illustrating a nightmare, it illustrates two sleep disorders, the first being of sleep paralysis, which is commonly reported in the normal population. It's also commonly reported in students because students tend to be burning the candle at both ends and tend to have slightly more disrupted sleep than average. And the other thing that it illustrates is something that often goes hand in hand with sleep paralysis, which is something called hypnogogic hallucinations. So what we think this represents is that during dreaming sleep, during REM sleep, we're completely paralyzed. The only muscles that work are the muscles that allow us to breathe, for obvious reasons, and also the muscles that move our eyes from left to right, which is where the term rapid eye movement comes from. But actually the rest of our musculature is completely paralyzed. In individuals with sleep paralysis, it seems that that mechanism of paralysis that arises in REM sleep is not switched off quickly enough when we wake up. And if that happens and there remain fragments of REM sleep that intrude into wakefulness, that can also be associated with hallucinations, which we think probably represents dream mentation spilling over into consciousness. Now if you can imagine that you're lying in bed and you're paralyzed and you can't move, it's perhaps not unsurprising that some of those hallucinations that you might experience of somebody sitting on your chest, of somebody pinning you down. The other types of hallucinations that people with sleep paralysis often experience are out of body experiences or an intruder in the room or standing over the edge of the bed. And we know that sleep paralysis and hallucinations, as well as being a feature of a range of neurological disorders, conditions like narcolepsy for example, are often much more likely to occur in anxious individuals because their REM sleep is much more likely to be disrupted and they're much more likely to wake up from REM sleep and experience these kinds of phenomena. This is something that might be familiar to to many people, which is what we term night eating syndrome. So night eating syndrome is one facet of eating out of sleep or at night. So the typical thing that we see in the neurological sleep services is something called sleep eating, which is a version of non-REM parasomnias, a version of of sleepwalking. These are individuals who will get up in the middle of the night, who will still be in all, in the truest sense, still be asleep and they will go down and seek out food. Now the key issue is that they will often eat things that are completely either toxic or something that they would not eat during the day. So the kinds of things that we see are vegetarians eating raw meat or occasionally individuals drinking things like washing up liquid or even toxic substances like bleach. But night eating syndrome is something slightly different. So these are individuals who will wake up in the middle of the night and will have this absolutely irrepressible urge to eat. They won't be able to go back to sleep until they've eaten. And it is thought that in some of these individuals there is a clear disruption of the circadian clock because the circadian clock as well as regulating when we sleep also regulates every other biological function and it regulates when we eat. And so disruption of the circadian clock can result in this kind of thing, whereby essentially your gut is telling you that it's time to eat. But actually what we see is that this kind of condition is seen at much higher frequency, unsurprisingly, in individuals with eating disorders, so bulimia and anorexia nervosa. And so actually sometimes treating any eating disorder with a psychological technique can dramatically improve night eating syndrome as well. And the final other setting that I want to mention is a group of conditions that are termed functional neurological disorders. So these are disorders that are not as a result of structural changes to the brain, they're not as a result of trauma or damage that we can see on scans or on electrical tests that we think have a basis in the function of the nervous system rather than the structure of the nervous system and result in things like paralysis or numbness, tremor, occasionally seizures that are termed non-epileptic seizures. And what we see anecdotally is that individuals with functional neurological disorders often experience very poor sleep indeed. And that improving their sleep also treats their functional symptoms. So I'm going to talk a little bit more about insomnia. What is the basis of insomnia? And I think that many of you will recognize the association between a dog and a bell. So this is really to illustrate Pavlov's dogs. Pavlov was the neuroscientist who really described the classic conditioning response. So he was a Russian neuroscientist at the turn of the century who was experimenting on the salivary glands of dogs. And he noted that when he entered into his laboratory, they would start salivating. He then started experimenting by ringing a bell every time he presented them with food. And within two or three days, every time he rang the bell, they started salivating. So really demonstrating this concept that all around us we have environmental stimuli that we associate with particular behaviors and those environmental stimuli may not necessarily be directly correlated to the behavior that we're exhibiting. So the reason why this is important is because it tells us a lot about what we understand insomnia to be. So insomnia used to be termed psychophysiological insomnia, which really illustrates the fact that there are psychological factors at play, but there are also physiological factors at play. Those psychological factors can be conscious or they can be unconscious. So when I talk about conscious psychological factors, many individuals with insomnia will experience an anxiety about sleep, they will experience an anxiety about the night ahead, the fact that their partner is snoring away while they're being tortured by wakefulness overnight, they'll experience frustration that they're not able to sleep, they'll experience anxiety about whether or not they can function the following day and participate in all the things that they want to. And importantly, especially nowadays, they will experience significant anxiety about the health issues that their insomnia may predispose them to, rightly or wrongly. And we can chat about that a little bit later. So those are the conscious factors, but it's likely that unconscious factors are as important as those conscious factors, because we all learn how to sleep. As children, we learn the fact that bed is a place where we sleep and we stay awake until our parents wake us up or until dawn wakes us up and then we're awake. But in individuals who have had significant sleep disturbance for a prolonged period of time, that conditioned response, that association between bed and sleep is replaced with a negative conditioned response, which is that bed is a place where we're awake, where we're having difficulty sleeping, where we're struggling to get off to sleep. And so what a lot of people do with insomnia is, and this is quite intuitive, is if you think you are going to get a bad night's sleep, you will stay in bed for a little bit longer, you'll try and catch up on your sleep. Whereas actually what that is successfully doing is strengthening that conditioned response between bed and being awake because you are extending the period of time in bed that you are awake rather than asleep. So that's what I mean by these unconscious psychological factors. And then finally there are the physiological factors. So we know that poor quality sleep causes endocrine changes that I've already mentioned. It results in an increase in cortisol levels and steroids are a very good way of inducing insomnia. And so those changes can then reinforce the insomnia and adrenaline is also increased and adrenaline is a very good way of inducing insomnia as well. So why do I tell you all of this? Well, because I think it gives a very good illustration of why we think that cognitive behavioral therapy for insomnia works. So there is the standard sleep hygiene advice that we've already discussed. Sleep hygiene is not going to make the difference between somebody who is a good sleeper and somebody who has chronic insomnia, it's not really going to help. If you have intermittent, poor quality sleep, then certainly paying attention to caffeine, paying attention to what you are doing during the day will help improve the quality of your sleep, but it's not, if you've got chronic insomnia going to miraculously resolve your chronic insomnia. And so over the last 20 years or so, this treatment called cognitive behavioral therapy for insomnia has been developed and this has been extensively researched. We now know it to be one of the most effective treatments for insomnia. It's probably as effective in the medium term as any drug we can give and in the long term it's probably more effective. So what is CBTi? Well CBTi is a multifaceted psychological intervention that involves attacking various aspects of the psychological factors that drive insomnia. So part of it is about stress management therapy, part of it is about relaxation and mindfulness-based therapy. But perhaps the most important part of cognitive behavioral therapy is essentially a form of brain retraining, where we try and reestablish that positive conditioned response between bed and sleep rather than bed and wake. And one of the ways we do that is with a module within CBTi, which is called sleep compression. So imagine that you are somebody who spends nine hours a night in bed and you're doing that because you know you are only sleeping for five or six hours a night and you're trying to maximize the amount of sleep that you are getting over the course of the night. That means you're spending two or three hours a night in bed, awake. So as part of this sleep compression protocol, what we would do is say, well, if you are only spending five and a half hours a night in bed asleep, then we want you, for a period of time, to restrict yourself to five and a half hours a night. So go to bed at five, go to bed at one and wait, sorry five, that would be quite hardcore, go to bed at one and wake up at 6:30 and get out of bed

when you wake up at 6:

30. Now in the first instance, in the first few days, that's going to be like torture. There's nothing worse than telling somebody who's got insomnia to spend less time in bed. But what that does is it drives mechanisms within the brain that are termed homeostatic mechanisms, essentially it's sleep depriving you a little bit more. And over time what that does is it encourages the brain to take advantage of the time that you are in bed and to go to sleep. And over time what we see is that sleep tends to be consolidated, that the sleep that people are getting is less fragmented, it's less broken, and is of better quality. And then with time that period of compression is eased. As you get better quality sleep, the amount of time you get to spend in bed is extended. Essentially what that is doing is it's re-driving the brain's association with the head hitting the pillow and going to sleep rather than staying awake. Now there is a rather more dramatic Guantanamo Bay style treatment that is out there, which is called intensive sleep retraining. Now for reasons that will become obvious, this is not really hit the mainstream, but it is being used in places like Australia largely on a research basis. So imagine you've got very bad insomnia, you are really not sleeping well at all. I'm going to ask you the night before you come into my sleep lab, not to sleep at all, to be completely sleep deprived when you come in, you'll be invited into my sleep lab at about nine o'clock in the evening having not slept at the night before. And I'm going to put some electrodes on your scalp and then at midnight I'm going to say, okay, I'm going to switch the lights off now and try and go to sleep. And if you manage to go to sleep, which I think is very unlikely being in a sleep lab in a strange environment with sensors stuck on you, then even if you do fall asleep, then after three minutes of sleep as verified by your brainwaves, I'm going to wake you up again and I'm going to do that every half hour for the next 25 hours. So you will have 50 opportunities to fall off to sleep over the next 25 hour period. Now imagine what that does. So you are already sleep deprived, you may not fall asleep at all in the first few naps, but within a short period of time you're going to be so sleep deprived because even if you fall asleep, you're only going to be allowed to sleep for three minutes. And that is going to happen every half an hour. Believe you me, by the end of that 25 hour period, every time the lights go out and you're told to go to sleep, you will go to sleep. Now you can imagine how unpleasant that is as an experience, but actually even that 25 hour period of intensive sleep re-training can significantly improve the sleep of people within insomnia. So I think it's a really good illustration of the role of that conditioned response, associating going to bed, lights going out, and drifting off to sleep in terms of addressing people within insomnia. Now this is very intensive, it's very torturous. I can imagine that a lot of people run screaming out of the sleep lab when you try this, but it is an effective treatment. There are of course other non-drug based options, treatments that are perhaps less mainstream. I just wanted to talk about one particular treatment strategy, which is called lucid dreaming therapy. So some of you in this room will be familiar with this concept of lucid dreaming. So this is the experience that when you are dreaming, you are aware that you are asleep and you are aware of dreaming. And sometimes individuals who lucid dream will also be able to control the content of their dreams, which has always struck me as a bit of a magical experience. It would be lovely to be able to control your dream mentation, your experiences at night. Now unfortunately, lucid dreaming has had a bit of a pseudoscience connotation to it and for many years it was really disbelieved as an entity. But actually one really fascinating study done in Germany a few years ago really illustrated that lucid dreaming has an underlying neurobiological basis. And in this study they got six people who said that they could lucid dream and they got them into a functional MRI scanner. Functional MRI essentially measures brain activity. And they got them to clench their left hand for 10 seconds, then signal with their eyes, so do a pre-agreed sequence of eye movement and then clench their right hand. And to do that in alternating ways. And what they demonstrated is that when they got them in the scanner to do that while awake, unsurprisingly when they clenched their left hand, their right motor area lit up and vice versa. And you can see that here, these are the areas that are corresponding to motor activity within the hand. So, so far, not very surprising. They then got these same individuals to get into the scanner and not to actually clench their hands, but imagine they were clenching their hands. So there was no physical movement, it was just the imagination of clenching their hands. And sure enough, what they demonstrated is that there was activity in the motor areas of the brain that corresponded to which side they imagined clenching, perhaps less marked, which is also unsurprising, but nevertheless, they showed similar patterns of activation. They then got these people into the scanner and asked them to fall asleep and to signal to the researchers when they were lucid dreaming with a pre-agreed sequence of eye movements. And in their dream they asked them to dream that they were clenching their left hand , then to signal with their eyes that they were switching hands, and then to dream that they were clenching their right hand. And what they showed was exactly the same pattern of motor activity. So very clearly demonstrating that this concept of lucid dreaming, which as I said was a bit of a scientific pseudo babble entity, very much had a basis in our brains. Now the reason why this is important is because there has been a real interest in the use of training people to lucid dream in order to seek control over the nightmares that they have in the context of PTSD. And actually there is quite good evidence that if you teach people to lucid dream and establish control over your nightmares, that's a very good way of treating nightmare disorder and treating PTSD as well. So this is a really fascinating area of medicine because 20 years ago this wasn't really even believed as an entity. So when it comes to treating people with psychiatric disorders, it's really worth making sure that you are addressing their sleep disturbance and considering whether or not they may have other sleep disorders at play. So many of the drugs used in psychiatric disorders cause people to gain weight. And when you gain weight you are at increased risk of obstructive sleep apnea, obstructive sleep apnea, which requires this mask in order to prevent the airway from collapsing. And we know that obstructive sleep apnea in and of itself can result in significant mood disturbance. We know that many of the drugs that are used in depression, schizophrenia and anxiety also put people at risk of a condition called restless leg syndrome. So this is a neurological disorder that results in uncomfortable sensations usually in the legs, but it can affect other body parts, that typically come on in the evening that result in a sense of agitation and can cause quite marked sleep disturbance. So the kinds of individuals that I often see are individuals who are being treated for depression or anxiety and actually their sleep worsened with their treatment because it goes unrecognized that actually, what it's doing doing, the treatment itself is generating the sleep disorder primarily. So it is really important that psychiatrists and indeed GPs who are treating psychiatric disorders on a regular basis, know what it is their drugs are doing or potentially doing to the patients they're prescribing it to. And then finally, I know I already mentioned this issue of the circadian rhythm, the association between the circadian rhythm and depression in children and in adults, the circadian rhythm can be adjusted. So we know that there are a number of extrinsic environmental factors that define what are circadian clock is set at. And these are termed zeitgebers, from the German for time givers. The most powerful of which are exposure to light and melatonin. Melatonin is a hormone that's secreted by our brains. It is a chemical signal to the brain that it is time to go to sleep. We tend to see in normal sleep as that melatonin levels tend to rise

from about 6:

00 PM onwards, peak at the time at which we want to go to sleep and then start dropping down shortly before waking. But in addition to it being a chemical signal for sleep, it is also an adjuster of the circadian clock. But it's really important to note one thing, is that depending on what time you give melatonin in relation to somebody's circadian clock, you can have really dramatically different effects. So if you give somebody a dose of melatonin significantly before their normal bedtime, you will shift their circadian clock forward. If you give it a little bit too late, you'll actually shift it back. And this is something term the phase response curve, it's the adjustment that melatonin makes on the circadian rhythm according to when it's given from a time perspective. And it's related to the individual's own body clock rather than the external clock. Which is one of the reasons I think why melatonin, at least in this country, is a prescription only medicine because you need to know what you are doing with it rather than doling it out willy-nilly. So I'm going to stop there. So I'm just going to stop with my conclusions and I think, I hope, I've shown you that sleep is fundamental to good mental health as well as good physical health, that sleep issues are not simply secondary to mental health issues and may actually be driving mental health issues, and that really sleep medicine should be a part of standard psychiatric care. One of the things that we're very bad at in this country and actually in other countries as well, is that we don't really train doctors about sleep particularly well. And hopefully that is gradually changing, but very gradually. Thank you.(audience applauds)- Thank you, Guy. As usual, I've got a whole stack full of questions coming in from wherever people are out there, which we'll start with before I open it up to the floor and I'm going to try and group some of them together. So there's a common question coming through is what's the difference in mental health terms between sleep deprivation, particularly say for shift workers or people like me, and insomnia? They're not necessarily the same thing as I understand what you're saying.- So you know, that's absolutely true. So I think that there is a wealth of evidence out there that chronic sleep deprivation has a number of very significant health consequences. So it has impact on blood pressure, cardiovascular disease, kidney disease, it increases cognitive deficits and can drive, we think, can drive dementia. And that's just a very, very small list, actually sleep deprivation is listed by the World Health Organization as a possible carcinogen. So there is very good evidence that actually chronic shift work, for example, increases your risk of breast cancer or prostate cancer. Insomnia is rather different because if you actually record the sleep of individuals who have insomnia using their brain waves, so we get a very clear physiological measure of their sleep. For most people with insomnia, their total sleep time is not that much different from normal individuals. And so one of the real distinctions, and I think that this drives insomnia in many cases, is that what has not been explained by the medical profession in general, and I think it to some extent it's confounded by a lot of the stuff that's in the media, is that for the vast majority of people with insomnia, those health concerns that they have about their insomnia are not applicable to them. There are a few individuals who have very, very short sleep times when measured on their brain waves, and we know that they are at increased risk of things like cardiovascular disease, but for the vast majority of people within insomnia, that's not the case. It's also worth saying that on an experiential basis, sleep deprivation and insomnia are not the same. If you take somebody who has got sleep deprivation and you say to them, get into bed and drop off to sleep, they'll fall asleep very, very quickly. If you put somebody with insomnia into a bed and say go to sleep, they'll lie there wide awake, completely wired. So that in itself tells you that these are two different physiological states.- Thank you, and the next question is more practical. So you've already outlined there's a lot of people out there with insomnia, but I'd rather suspect that CBTi is not available to most of them.- Yes, I mean I think huge inroads have been made into that over the last few years. So I think last year NICE approved a digital form of CBTi and indeed in a number of different areas of the country, GPs can directly refer for free to two or three digital CBTi platforms. There are some that are free for use even without prescription. Now obviously that's not suitable for everyone, but I think in terms of improving accessibility to this treatment, it's a huge step forward. Getting face-to-face CBTi remains a bit of a challenge.- [Audience Member] Yes, thank you. I wanted to ask you about age related sleep issues where typically, have less REM sleep and wake up, early morning waking. Is that something to be accepted as normal because it just happens with age or is it something that needs treating?- I think it's a question of degree really. So we know that actually our circadian rhythm changes throughout life and typically in teenagehood and I'm experiencing this now trying to pry my kids out of bed in the morning, our circadian rhythm delays, it gets later. And actually as we get older, our circadian rhythm advances, and that's part of normal physiological function. Now the other thing that happens we age is those circuits that stabilize our sleep are slightly less effective. And so insomnia tends to be a bigger issue as we get older. In terms of incidence, in prevalence, it's cumulative. But I guess the big question is if you are going to sleep and waking up at roughly the same time and you're waking up feeling refreshed and you're not suffering due to cognitive effect or sleepiness during the day, then you're probably sleeping enough.- [Audience Member] Thank you, you've more or less answered the question I was going to ask. I just then wanted to make a quick comment, which is I was so glad you mentioned lucid dreaming. I went to a lucid dreaming weekend with Charlie Morley and it was fantastic and has really improved my sleeping, so thank you.- Quick advert for a lucid dreaming course.- [Audience Member] Thank you. What if an individual only lucid dreams and these lucid dreams end in an abrupt manner which ends in resulting of an incomplete sleep, would you say there's underlying mental health issues to that?- To sorry, to?- [Audience Member] for an individual having only lucid dreams or only the dreams that he or she can remember are lucid dreams?- Yeah, well I think there are two things. So the first thing is that if you are not a lucid dreamer and you're waking up from your dreams on a regular basis, and I think that tells you something about your sleep quality. So the kinds of things that we see people having very strong recollection of their dreams are individuals who, for example, have got sleep apnea, and who are having recurrent awakenings from REM sleep as a result of closure of their airway. But in lucid dreaming, this is slightly different. So actually there is some evidence that in lucid dreaming, and this is controversial, and it's not been replicated extensively, is that actually lucid dreaming illustrates one of these examples of local sleep. So what I mean by that is we've moved very much away from viewing sleep as a global brain state. So different parts of the brain can exist in different stages of sleep and wake at the same time. And in fact that's probably even the case for some of you out there, which is that actually during wakefulness, we constantly see little small islands of sleep occurring within your cerebral cortex, some of you more than others maybe. And in lucid dreaming, this is probably another example of local sleep in that the majority of the brain is asleep, but the part of the brain that is responsible for awareness, and there is some interesting work looking at whether or not those areas of the brain that we see exhibiting some sort of waking like behavior may be part of a network called the default mode network, which is essentially what's responsible we think for consciousness, for awareness, or internal experience, may be awake, but actually the rest of the brain remains asleep. So it may be much less of a problem for people with lucid dreaming. I don't think we fully know though.- [Audience Member] Your reference shows a strong correlation between poor sleep and poor mental health, and I was just wondering how true that holds across all kinds of societies or across the historical record. I mean away from like modern city life, electric lights, screens, everything else.- Yeah, I mean I think the short answer is we don't know, because these kinds of studies were not done in Elizabethan England or in hunter-gatherers. What we can say is certainly when you look at some of the epidemiological work that's been done, there is some really fascinating work that has looked at hunter-gatherer communities in places like Peru, in Namibia, and in Laos and Cambodia. And so these are pre-industrialized societies and what they find is that insomnia seems to be a much lesser problem for them than it is, in fact, in some of these societies, the word for insomnia doesn't actually exist.- Well, thank you very much. Thank you much everybody and Professor Leschziner, thank you for a wonderful evening and talk.(audience applauds)