I've seen patients cooking a meal in theirsleep, who've driven in theirsleep, committed crimes in theirsleep.
So what is the story of KennethParks?
He drove several miles to his in-lawshouse, bloodshed his mother-in-law todeath, and then tried to kill hisfather-in-law.
But it was deemed he wassleepwalking, and he was actuallyacquitted.
That'scrazy.Dr. Guy Leshner is a leading neurologist in sleep physician at one of Europe's largest sleepclinics.
And with over 25,000 studies of over 100,000patients, his pioneering research in sleep medicine has provided the answers we need to improve oursleep.
So many people are chronically sleepdeprived.
30% will experienceinsomnia, and80% of people in the UK don't know that they've got sleep atnight.
This is theproblem. But the majority can behelped.
So let's get intothat. Is this such a thing as healthysleep?
Somewhere between seven and eight and a half hours anight.
Now, what's difficult to explain is why your all-course mortality goes up if you're sleeping more than eight and a halfhours?
Is there a link between sleep deprivation and weight gainincreases?
So even a single night of sleep deprivation can result in a dramatic increase in calorieintake.
And that'sbecause... What hope would you offerinsomnia?
There are very effective treatments forinsomnia.
Forexample, ifyou... We know thathelps.
About80% ofindividuals.
Are you a fan of sleeptablets?
As a generalknow, because there are many non-grub basedtechniques.
What are these techniques to improve oursleep?
The gold standard treatment nowis...
Guy, why do wedream? That's a really importantquestion.
The honest answeris...
Guy. Should Isay, DoctorGuy?
What is it that is at the very sort of heart of your personalcuriosity?
Because as I look at your work and what you've committed your careerto, there seems to be a bit of a through-line as to sort of the subject matters that have capturedyou.
So I've always been fascinated why we are the way that weare.
Andobviously, from a scientificperspective, the core of that is ourbrain.
And in the course of my clinicalpractice, I come across a whole host of individuals who really sit at the extremes of the humanexperience.
Youknow, people who are sometimes afflicted by very serious neurological conditions who experience the world in a very different way to how wedo.
Soreally, at the core of what Ido, particularly in the public-facing work that Ido, it's looking at those people at the extremes of the human experience and trying to work out what it tells us about all ofus, about how we allwork.
When you say the extremes of the humanexperience, what does thatmean?
So individuals whohave, who see the world in a very differentway, experience the world in a very differentway, understand the world in a very differentway.
So, youknow, from when it comes to individuals who have very extreme sleepdisorders, to individuals in whom the perception of reality is very different from ourown, or to people who behave in a very differentway.
So when it comes to things like aggression or the way their relationship with food or their personalitytraits, I think in every area of clinicalneurology, you see individuals in whom something has happened to their brain that fundamentally changes the way they see theworld, interpret theworld, or behave within thatworld.
And what's your sort of day today, and if I was to take a look at yourCV, what would I see on yourCV?
I studied medicine at Oxford and then atImperial, and very early on in my career started training in the world ofneurology, did a PhD at Imperial andCambridge.
What isneurology? Neurology is the clinical study of thebrain, so the brain in its diseasestate.
So we see individuals withepilepsy, with Parkinson'sdisease, with nerveproblems, with certain types of sleepdisorders, basically any disease or disorder that influences how the brain and the nervous systemworks.
So I did a PhD at Imperial and Cambridge looking at the genetics of epilepsy and then started working as an NHS consultant in2010.
And you're a consultant of neurology and sleepmedicine?
That'sright,yeah. I've never heard the phrase sleep medicinebefore.
Well, sleep medicine has been around for a longtime.
I was very lucky in that early on in my trainingperiod, I rotated through a hospital where one of my now colleagues had actually come from the UnitedStates.
He'd been based in LA where sleep medicine was really startingout.
And he'd set up a sleep medicineunit, and that was atSt.
Thomas's Hospital in London opposite the House ofParliament.
And certainly over the last 20 or 30years, this has been a really exploding area ofmedicine, partly mirrored by the fact that we are much more aware of the impact of sleep on a range of biological and mental healthissues.
But actually in the world ofneurology, there are many sleep disorders that have their basis in thebrain, conditions likenarcolepsy, like people who sleep walk or act out theirdreams, people who have episodes at night that may or may not reflect certain types ofepilepsy.
So that's really the primary focus of my worknow.
Between 2013 and2023, you ran Guy inSt.
Thomas's Hospital Sleep DisorderCentre.
That'sright,yeah. What isthat?
So the sleep disorder centre is probably one of the largest sleep disorder centres inEurope,actually.
So we have 10 inpatientbeds.
So everynight, 10 people are brought into the sleeplaboratory, and we study theirsleep.
It's got now about 15consultants, it's got a staff of about 50people.
And we see a range of people with conditions like sleepapnea, which is where people stop breathing atnight.
And then some of the conditions that I've talkedabout, conditions like restless legsyndrome, extreme sleepwalking,narcolepsy, another relatedissues.
How many patients have you had in your sleep disorder centre that you'vestudied?
Gosh, an awfullot. So we do about 2,500 sleep studies ayear.
And we've been goingfor,well, a longtime, sort of15, 20years.
So every year we see about 10,000 patients intotal, sovery, very largenumbers.
If you had to estimate how many you'veseen?
I would imagine somewhere in the regionof, upward of100,000, if we're talking about 10,000 patients ayear.
And how many sleep studies have you conducted in thatcentre?
So we've been at the current site with 10 beds for about 10years.
And so we're probably talking about 25,000studies.
Whysleep? Of all the things that you could commit so much of your timeto, because it appears you've been really thinking and working on the subject matter of sleep for about 20 or twodecades,roughly?
Yeah, something likethat.
What,why?Well, I think the first thingis, is that we spend a third of our lives doingit.
And yetwe, whatever people like me will tellyou, we still understand relatively little aboutit.
We understand relatively little about what it'sfor, what it does to ourbiology.
Obviously that's changingvery, very quicklynow.
It has a great deal of overlap with the world of clinicalneurology.
So I also do a specialistclinic, a specialist clinic inepilepsy, an ID specialist clinic in generalneurology.
So, and sleep and the brain intersect to every singlelevel.
Ofcourse, youknow, it's not me sayingthis, but a famous statement is sleep is of the brain by the brain and for thebrain.
It's in intimately linked to every aspect of how our brainworks.
So one of the really exciting things is that because it's a relatively new area or our understanding of it is exploding in ways that are not parallel across other areas of clinicalmedicine.
Is itimportant? Is itimportant?
Yeah. I think it is of fundamentalimportance.
Youknow, the fact is that if sleep wasn'timportant, it would be a very stupid thing for evolution to create inus.
The fact that we are essentially switched off from our external environment for a third of ourlives.
And actually there's a whole host of evidence when you look at how certain animals have developed the ability to be able to sleep with only half their brain at atime.
Youknow, animals like aquatic mammals or certainbirds.
Thedolphins. And dolphins that very muchsuggests,well, youknow, that must be of great importance if sleep is a risk for oursurvival.
Because if you're an aquaticmammal, like adolphin, and you're sleeping and you're unable to surface or unable to see what predators are aroundyou, that the evolution has designed a system where by it enables you to sleep with half of your brain at atime.
So that in and of itself tells us it'simportant.
The fact that the circadianrhythms, so that 24-hour cycle that a whole host of biological rhythmshave, is so intrinsically linked to life itself that actually every single life form exhibits features of this 24-hour circadianrhythm.
It tells us that this was something that was prioritized at avery, very early stage in life's evolution onEarth.
Soyes, it'simportant.
And over the last fewyears, we've understood precisely why it'simportant.
I sayprecisely, but we know that it's important for pretty much every aspect of our wakinglives, be it our immunesystem, be it our cardiovascularsystem, our bloodpressure, risk ofdiabetes, mentalhealth, so depression andanxiety, even how we perceivepain.
So it really is fundamental to every system that we rely on during our wakinglives.
Having seen thousands and thousands and thousands of people that struggle with sleep that have been sent to yourcentre, do you think the average person on the street over or underestimates the importance of sleep in their day to daylife?
Well, I think it'schanging.
I think it was not that long agowhere, youknow, comments like sleep is for whims was heard fairly frequently and that there were some bragging rights associated with how little yousleep.
I think that there has been a transformation over the last sort of 15 or 20 years whereby people have become much more aware of how important sleep is and have started prioritising it a littlebit.
So youthink, where do you think we stand thenoverestimate,underestimate?
I think that there is still in the general population an underestimation of how important sleepis, but I think there are certain segments of the population that are much more aware of it and perhaps even dare I say overestimateit.
Overestimateit?Yes, I thinkso.
I think that there is a danger at the current time that we tend to obsession lies about sleep and think that it is the be all and endall.
It's of course part of normal life for our sleep to fluctuate depending on what's going on in our external and our internallives.
And I think the danger is that if you overemphasise the importance of getting eight or eight and a half hours sleep everynight, then you actually risk problems later down theline, exacerbating things likeinsomnia.
Can you give me an overview of the current state of sleep in terms of the percentages stats of people that are struggling with theirsleep?
The variety of ways that we struggle with oursleep, the different disorders associated with oursleep, and just like a breakdown of society at large is current sleephealth.
So we think that about20% of the adult population are chronically sleepdeprived, so that they are not sleeping enough and that's largely as a result of lifestyle factors and lack of prioritisation ofsleep.
We think we know that about30% of the adult population in any one year will experience a period ofinsomnia.
So insomnia is different from chronic sleepdeprivation.
Insomnia is the state whereby you want to sleep where you're lying in bed and you can'tsleep, which is very different from burning the candle at bothends.
And about10% of the adult population will have chronicinsomnia, so that's an ongoing issue with not being able to sleep for more than three months at atime.
Sovery, very highnumbers.
And some other sleep disorders that are incrediblycommon, so a condition called obstructive sleepapnea, which is essentially part of the spectrum ofsnoring.
But in obstructive sleepapnea, your airwaynarrows, you have difficultybreathing, it partiallyobstructs, and you have recurrent briefawakening, sometimes that you're not awareof, that disrupt yoursleep.
Estimates were verywildly, depending on where in the world that they've beendone, but I think our best guess is something like10% to12% of adult males experience sleepapnea, clinically significant sleepapnea, and somewhere in the region of about6% of women experience clinically significant sleepapnea.
So we're talking aboutvery, very largenumbers, and the majority of individuals with sleep apnea areundiagnosed, so it's estimated that about80% of people in the UK with sleep apnea don't know that they've got sleepapnea, and have never seen anybody about sleepapnea.
There are other conditions like restless legssyndrome, which is a neurological disorder whereby people experience an urge to move a fidgetiness intheir, usually theirlegs, although it can affect other body parts aswell, that can give rise to very huge difficulties getting off to sleep and actually stayingasleep, because a lot of these individuals kick at night when they are asleep and kick themselvesawake, and that probably affects somewhere in the region of about5% of the adultpopulation, even sleepwalking, 1 to2% of thepopulation, so lots and lots of theseconditions,very, verycommon.
How many of the people that walk in your sleep centre do you think could be helped and could youhelp?
Well, I think the majority can behelped, a cure is somethingdifferent, but the majority can be helped in some shape orform.
And if we talk about getting someone that is walked in your clinic with some kind of sleep disorder to a state where they are a healthysleeper, what kind of percentage do youthink?
Well, I think it's important to proceed what Isay, rather thanactually, we don't see many people withinsomnia, we tend to divert people with what we turn primary insomnia or insomnia without any underlying causes to assist aservice.
If you look atinsomnia, chronic insomnia as awhole, we know that there are some very good treatments for chronicinsomnia, and actually most of those treatments are focused on non-drug-basedtreatments, psychological-basedtreatments, and we know that those kinds of treatments will significantly improve sleeping up to about80% ofindividuals, so that's a very largenumber,actually.
And there are other treatmentsavailable, it doesn't just rely on these non-drug-basedtreatments.
There are some conditionslike, forexample,narcolepsy.
What'snarcolepsy?So, narcolepsy is a brain disorder that is triggered by your immunesystem.
Is that where you fall asleep during theday?
During theday. When you fall asleepvery, very quickly during theday, you're excessivelysleepy, you have very vividdreams, you will often hallucinate as you drift off to sleep or as you wakeup, you'll experience something called sleepparalysis, where you wake up and you feel that you are completelyparalyzed, you cannotmove, and a lot of these individuals also experience a condition calledcataplexy, which is where usually with strongermotion, likelaughter, sometimes it can be the telling of ajoke, and they lose muscle strength and will sometimes collapse to theground.
So, it's a very pure neurological disorder because we know precisely where that area of immune attack occurs within thebrain, and it knocks out a very small number of brain cells to generatethis.
This isa, youknow, once you have it at themoment, it's a lifelongcondition, but actually it can betreated, there are many treatmentsavailable, and even in the last five yearsalso, there have been many new treatments that have becomeavailable, so actually all of these conditions aretreatable, they'remanageable, they're not necessarily orcurable.
Is there something at the heart of culture and how we'reliving, that's causing so many of us to struggle withsleep?
The way that modern society is at the moment ofcertainty, I think it's rather conducive toinsomnia, infact, youknow, when researchers have looked at pre-industrializedsocieties,so, youknow, forexample, tribes in Eastern Africa or in South Americaactually, insomnia is relativelyrare, and some of these tribes don't even have the word forinsomnia.
So I think that there's certainly insomnia seems to be correlated with the changes that have occurred in oursociety.
Sleep apnea is often associated with weightgain, and obviously that is very much a function of our modernsocieties.
Soyes, undoubtedly some of these conditions can be attributed to the way that we lead ourlives.
Has anybody ever put like a sleep tracker on atribe?
Yes, that has beendone, there's a chap called Jerry Siegel who is based in the East Coast in one of the Ivy Leagueuniversities, who has spent his life doingthat.
What did he findout? So he found out that actually sleep does vary a little bit according to the seasons that they don't necessarily sleep all the way through thenight, but actually their sleep is rather different to the sleep of modern society in whatway?
They will notnecessarily, so this view that we sleep when it gets dark or used to sleep when it gets dark and wake up at dawn isincorrect, that there is some fluctuation between theseasons, but not necessarily directly related to the number of hours ofdaylight, and that insomnia is relativelyrare.
So are they waking up in the middle of the nightthen?
I think it's normal to wake up in the middle of thenight, that we all wake up in the middle of thenight.
It's very rare thatyou, forexample, do a sleep study on somebody and you don't see periods of wake in the middle of thenight.
It's normal to be awake for up to about 30 minutes over the course of thenight.
That in itself is not a marker of pathologicalsleep.
When I sayawake, Imean, I guess I mean getting up and walking around andstuff.
Yeah, Imean, I think that there are some individuals who dothat.
There's a chap called RobertE.
Kirk, who has spent a great deal of time looking at medieval texts and seeing how they describedsleep.
He has put forward a hypothesis that in medieval times people would have a first sleep and a secondsleep.
Now, I think that that theory is not universallyaccepted, but certainly for some individuals getting up and walking around is certainly within the realms ofnormality.
I think there are different sleeppatterns.
If youlook, forexample, at MediterraneanEurope, the CESDAculture.
So people sleeping for an hour or two atlunchtime, but sleeping slightly less atnight.
So there are a range of sleep patterns that sit within the spectrum of normality for humanbeings.
Is there such a thing as a healthysleep, asin, youknow, see these sort of different sleep behaviors andsuch?
But is there from a neurology standpoint or a clinicalstandpoint, a perfect sleep or a perfect sleeping habitor, youknow, So I think the first thing to tell you is that sleep is different foreveryone.
We know that there are genetic factors thatinfluence, forexample, your timing ofsleep, your circadianrhythm, whether or not you're amorning, dark or anevening,out.
There are also genetic influences over how much sleep weneed.
So, forexample, there are one or two families that I've seen in my clinical career in whom every single member of that family sleeps for four hours a night and has no illeffects.
And does not seem to have any long-term consequences fromthat.
They don't feeltired. There's no evidence that they're doing their physical health anyharm.
And there have been some genes that have been identified that define that traitnow.
It's a raretrait. And I wouldn't suggest that most people who are sleeping for hours and Ithink, I must be genetically blessed because the reality is probably somewhatdifferent.
So I think that in answer to your specificquestion, is there a perfect nightsleep?
No, there isn't because it depends on the nature of who you are and what your genetic inheritanceis.
But certainly we can stay on a populationbasis.
Well, youknow, sleeping somewhere between seven and eight and a half hours anight, if you look and I stress on a populationbasis, we see ill effects in terms of sleeping less than seven hours or sleeping more than eight and a halfhours.
If you lookat, forexample, all cause mortality or if you look at cardiovasculardisease.
Now, there are various potential explanations forthat.
Certainly if you're sleeping relativelylittle,you, we can see that there are changes in terms of how your physiological system works that might give rise to things like blood pressureissues, weightgain, cardiovasculardisease,stroke, those kinds ofthings.
What's a little bit more difficult to explain is why your mortality and other ill health goes up if you're sleeping more than about eight and a halfhours.
And I think that that is probably a much more complicated picture in that we know that there are certain drugs that people will beon.
And when you're ondrugs, that's a marker that your health is not necessarily100% already that will make you a bit more drowsy than you normally are and will extend your sleeptime.
Maybe that you have a sleepdisorder, which is causing you to sleepmore.
But there's another interesting potential explanation in that we knowthat, forexample, in certain diseases of thebrain, there are changes to your sleep many yearsbefore, sometimes even decadesbefore.
A good example of that is Parkinson'sdisease.
So we know that in people with Parkinson'sdisease, many individuals will start acting out their dreams atnight, sometimes even three decades before they then go on to develop Parkinson'sdisease.
So is it that our sleep intrinsically changes in as a precursor to certain conditions like Alzheimer'sdisease?
And there is some emerging evidence now that actually a change in your sleepingpatterns, either in terms of how deep will yousleep, how long yousleep, whether or not you nap during the day that may be a what we term a pro-dromal feature of Alzheimer'sdisease.
Do you see anything interesting happen when someone has a baby in terms oftheir...
I was wondering this the other day because I have a friend who's had a couple ofkids.
And I was looking at their sleep tracker and it seems like they have this inherent ability to survive now that they've had kids on like nosleep.
I was wondering if there's some sort of evolutionary mechanism that makesparents, I don'tknow, require lesssleep.
Yeah, I'm not sure I can specifically answerit.
I've certainly seen a lot of people who sleep has gone to pots after they've hadkids.
And youknow, a lot of people say that their sleep has never returned normal after they've survived having a couple ofkids.
But you know what you have to remember is that the brain is a remarkable organ in that it has all of these adaptive mechanisms that enable us to cope with changes in ourcircumstances, changes in ourenvironment.
So if you put somebody in a sleep deprived state sleep alsochanges.
So what what the brain does is it prioritizes the very deepest stages of sleep stage three slow wave sleep over other stages ofsleep.
And you know what we can see that in the sleeplab.
So if somebody is very sleep deprived before they come in and we put them in the sleeplab, we see a sort of huge increase in their slow wavesleep, which is the stage of sleep that's most associated with restoration with healing with feeling feeling more refreshed than other stages of sleeplike, forexample, REM sleep or dreamingsleep.
So the brain is prioritizing restoration faster than it would because the person sleepdeprived.
Absolutely.Yeah. So what isthe, as you were sayingthere, you've seen families that just require four hours sleep and they're apparentlygreat.
Isthat, is that a lot ofpeople?
No, it's a said it'svery, veryrare, very rare because I've looked at people sleep trackers before and I've been astonished by how little sleep they seem torequire, but how active and great they seem tofeel.
And I've had this the other day because one of my fellowdragons, I said this toher, she requires very littlesleep, but then she gets up at 5 AM and goes for like a 10 milerun.
And I waslike, I was looking at her sleeptrack, I think you've been in bed for like five hours and you are extremely more awake and energetic than I am and you just did a 10 mile run and I'll go in bed for sevenhours.
And it says that my stage three stage four sleep is higher thanhers.
But for somereason, she's like bouncing into theroom.
Well, I think there's two explanations forthat.
The first is maybe she is one of these genetically shortsleepers, as Isaid, that seems ratherunlikely.
I think the other explanation is we knowthat, youknow, I talked a little bit about how genes influence oursleep.
We know that there are genes that influence how resistant you are to the effects of sleepdeprivation.
And what I mean by that is that thereare, there seem to be some individuals who don't feel or who feel less sleepy than other people when they are sleepdeprived.
But that may be separate from the cognitive effects of sleepdeprivation.
So she might just not feelit.
She might not just feelit, but she may exhibit those cognitive effects of sleep deprivation in the same way as you orI, forexample.
She's 10 years older than me aswell.
Does that havewell, I think that the certainly we do see some reduction in sleep requirement as we getolder.
We're also a little bit less about less good amount maintaining sleep as we getolder.
And that's because the brain mechanisms that stabilize sleep are becoming a little bitweaker.
So this view that we need much less sleep as we get older is probablyincorrect, although there is a slight reduction in sleeprequirement.
You mentioned earlier that when people don't get enoughsleep, the chance of obesity and weight gainincreases.
How does thathappen? What's themechanism?
So there are probably manymechanisms, but one of the ones that is best understood is that we know that when you're sleep deprived or indeed when your sleep is disrupted by anything elselike, forexample, sleepapnea, there are changes that occur in terms of hormone levels of hormones that regulate our appetite and oursatiety.
And so even a single night of sleep deprivation can result in a dramatic increase in your calorie intakeovernight.
There have been some studiesdone, forexample, innurses.
So there was a study done that followed up nurses for 18years.
And they looked at their weight and how much they slept on a regularbasis.
And what they found is that those nurses that were sleeping less than about six hours a night on a regularbasis.
First ofall, started off at the beginning of that 18 year period at a slightly higherweight, but over the course of those 16years, 18years, they put on much more weight than othergroups.
So there is a very clear correlation between sleepduration, sleep quality and weightgain.
We seethat, forexample, in individuals who we treat with sleepapnea.
One of the treatments for sleep apnea is a mask-like device that you wear that stops your airway from closing now and atnight.
And for some very overweightindividuals, actually when you treat their sleepapnea, they do manage to successfully lose weight where in thepast.
They found it absolutely impossible to doso.
Okay, so if I'munder-slapped, I'm more likely to eat more calories the nextday.
Am I also more likely to reach for foods that are high in sugar and bad forme?
Certainly some studies do suggestthat.
I think it's also important to say that sleep disruption or sleep deprivation has some fundamentaleffects, forexample, on your glucosetolerance.
So your insulinresistance.
Which of course is a particular issue for people withdiabetes, but it affects usall.
So if you're very sleepdeprived, there are changes to the way that not only your appetite or what you're reachingfor, but also how your body processes the breakdown of thosefoodstuffs.
Interesting. Becauseanecdotally, I think I can clearly say that if I'munder-slapped, I'm much more likely to eat something that is high in sugaror...
Well, I think we can all testify tothat, can'twe?
I think everybody has known that situation where they're very sleep deprived and theythink,oh,well, I just need a bit of chocolateor...
What's going on in thebrain,though?
Is it something to do with the amygdala and the prefrontalcortex, the emotional centre of ourbrain?
Yeah, I don't think weknow.
I think it's probably to do with the reward mechanisms that underlie our behaviors that there is something about sleep deprivation that alters the rewards that we'reseeking.
But I don't think I can give you a clear answer onthat.
You also talked about circadianrhythms.
If I was aten-year-old, what do I need to understand about the circadianrhythm, what itis, what itdoes, and why it'simportant?
So, within pretty much every cell of ourbodies, there is this 24-hourclock.
And infact, if you take a single cell and stick it in a petridish, about40% of the genes within that cell will exhibit this 24-hourcycle.
And that 24-hour cycle really controls pretty much every biological system within ourbodies, be it how our liverworks, how our heartworks, how our lungswork.
There is one particular area of the brain called the super-chismatic nucleus that is viewed as the masterclock.
It's the clock that coordinates all the other clocks within ourbodies.
And that influences not only all of these other clocks that are occurring within the cells throughout ourbodies, but influences our behaviour aswell.
So, influences generally speaking when we feel tired and when we want to go to bed and when we wakeup.
And also influences thingslike, youknow, when we feel most mentallyalert, when we want toeat, when we want todrink, when we feel most able to cope withwork, forexample.
Now, that circadianrhythm, that circadianclock, for mostpeople, confers the sleep onset of somewhere between 10pm andmidnight, if you're anadult, and waking up somewhere between 6 and8am.
Now, the timing of that body clock is governed by twothings.
It's governed by ourgenetics, so whether or not we are genetically predetermined to be slightly later in terms of our body clock or slightlyearlier.
And we see that in families where lots of peoplewith, forexample, willsay,well, youknow, I've always gone to bed late and woken uplate, but so as myfather, so as mygrandfather,etc,etc.
But it's also influenced by what's happening in ourenvironment, about50% of the definers of our circadian clock are governed by what's going on aroundus.
Be that in terms of when we're exposed tolight, so we know that light is a very important driver of our circadian rhythm when we'reeating, when we'reexercising, when we're doing a whole range of otheractivities.
And also one of the markers of our circadian rhythm is the decretion ofmelatonin, so there's a very small gland in the centre of our brains called the pinealgland, which secrete a hormone calledmelatonin.
That hormone tends to start being secreted in most people at around 6 o'clock in theevening.
It peaks at the time that we want to go tosleep, and then it's not stropping down a few hours before we wakeup.
It's almost a chemical marker of our circadianrhythm, but we also know that giving people melatonin in tabletform, forexample, can influence our circadianrhythm.
So there's this sort of feedback loop between our ownbodies, secretion of melatonin and what our supercarsmaticnucleus, our master clock isdoing.
So by giving people melatonin at particular times of theday, we can shift your circadian rhythm forward orback.
So that master clock in thebrain, where is itpositioned?
The supercarsmatic nucleus is in a small area of the brain called thehypothalamus.
And is that linked to theeye?
There are links from the back of the eye to thehypothalamus, so there are some cells in the back of the eye in the retina that are not involved invision, not involved in consciousvision, but what they are involved with is detecting blue light inparticular, which is the part of the spectrum oflight.
Most important in terms of regulating our circadianclock, and there are direct links between these cells that are called red and no ganglion cells and the supercarsmaticnucleus.
So exposure tolight, to blue light in particular is really very important in reinforcing or adjusting our circadianrhythm.
Now of course we live in a world whereby the seasons change and the amounts of light that we're exposed tochanges.
So if we were on a set rhythm all the time that was immovable andunadjustable, then there would be times where our circadian rhythm might not be might might be odds with ourenvironment.
So there does need to be some slight adjustment of that circadian rhythm and light is probably the most importantadjuster.
Bluelight, is that the light that comes from mysmartphone?
So blue light obviously the strongest source of blue light issun.
Butyes, these kinds ofdevices, yoursmartphone, your iPad in front ofyou, a range of electronic devices also have blue light withinthem.
So that's why if I'm up on my phone until 1am in themorning, staring into thescreen, I'm kind of tricking that sort of optic nerve which is then impacting my master clock and I'm telling it that it's a differenttime.
Yeah, so the thinking on that has changed a little bit over over the last fewyears.
So youknow, it was said that using these devices will trigger insomnia as a result of blue lightactually.
It's likely that the amounts of blue light that these devices put out is probably insufficient to do thatdirectly.
There are two effects of using your gadget until1am.
The first is on a long termbasis, if you're doing thatregularly, it will result in an adjustment of your circadian clock and push itback.
So you will want to go to bed a little bit later and wake up a little bitlater, which is fine if you're self employed or you don't have any restrictions on yourtime.
So this must have us need to be up at a certain time in the morning and if your circadian rhythm is delayedsignificantly, the net effect of that is that you're going to end up sleepdeprived.
Imean, there's also the issue of being on Twitter or being in grossed in a movie on Netflix at 1am that is going to make you delay sleepanyway.
So there are those twoeffects.
It'sarousing. It's arousing and it grips yourattention.
What would you make of thesepeople?
I'm leaving one of them that watch serial killer movies when we fallasleep.
Well, I think that that's only an issue if it's stopping you from fallingasleep.
Do you seeit? Because I have this argument a lot with mypartner.
She can't understand why I need to watch this really stimulating stuff when I fallasleep.
She likes quiet and I needto, I tell myself I need to listen tosomething.
Do you see like variants in this kind of thing and is there a better approachor?
This comes down to an individualized approach to sleep and that's why I'm always very reluctant to say this is the perfect nightsleep.
These are the rules forsleep.
Forexample, there are some people who for whom caffeine doesn't really influence their sleep and can have a double espresso an hour before bed and still have no problems getting off tosleep.
For most ofus, that's not thecase.
If you are somebody who can watch something verystimulating, very scary and then switch it off and roll over and go off tosleep, then I guess that's not a problem foryou.
For mostpeople, that's probably not the best thing to be doing atnight.
I think that longterm, one of the issues is with all of these kinds of activities in bed at night before you go off tosleep, is that they weaken the psychological associations between bed andsleep.
And so if you start associating bed being a place where you're mentallyactive, where you'reengaged, then if you have an underlying predisposition toinsomnia, forexample, then that can sometimes set the stage for developing insomnia lateron.
The average person that you've treated worked with in your clinical practice that's struggling with sleep is at the heart of theissue, just pour sleephygiene, like you've saidthere.
Because I've got so many friends that say to me that they struggle with theirsleep, many of them have struggled with it foryears.
And I doubt there's some genetic reason why this many people are struggling withsleep.
So I imagine it's just some kind of behavioralreason.
So I think that the genes that predispose to insomnia are prettywidespread, butobviously, youknow, in pretty much all areas ofmedicine, there is an interaction between genetics andenvironment.
And certainly pour sleephygiene, and that's a horribleterm.
I hate thatterm, but it's the term that is most widely used andunderstood.
Can certainly put in place certain aspects of behavior that then can give rise to chronic insomnia in the longterm.
So if you've got very bad chronicinsomnia, then suddenly putting good sleep hygiene inplace, it's unlikely to fixit, but it may be that that pour sleep hygiene in the first instance gave rise or at least predisposed you to developinginsomnia.
And what is pour sleephygiene?
If I wanted to be the worst possible sleeper in theworld, what would I have todo?
So I think you would probably have to set up your home office in yourbedroom.
Okay. You'd have tohave, youknow, your TV on in your bedroom all thetime.
Okay. Have be surrounded by electronicdevices.
Drink a lot of coffee late in theevening.
Alcohol? Drinks a little bit ofalcohol.
So alcohol in the shortterm, ofcourse, is quitesedating.
It's a central nervoussystem, adepressant, but it does dramatically worsen the quality of yoursleep.
And for variousreasons, the direct chemicaleffect, the fact that you've got a fullbladder, the fact that you're probably snoring a little bitmore.
So alcohol is not a goodthing.
And, youknow, not having a wind downperiod.
So, youknow, gambling on the stock market until 1a.m.
switching your laptop and then trying to go tobed, those kinds ofthings.
Sothat's, youknow, the quintessentialvery, very bad sleephygiene.
What about when Ieat?So, youknow, eating is perhaps lessimportant, but avoiding a very large carbohydratemeal, carbohydrate rich meal before you go to bed for tworeasons.
One is that we know that it can cause some fluctuation in terms of your bloodsugar.
Andalso, if you've got a bit ofreflux, it can make that muchworse.
Okay. What about sleeping in bed with somebodyelse?
Well, I think that for somepeople,they, andagain, this goes back to no one rule foreverybody.
Youknow, if you've got a sleep traitterm, sleepreactivity, which is where your sleep is very liable to yourenvironment, then obviously sleeping next to somebody who's snoring loudly or who gets up in the middle of the night two or three times to urinate canbe, can be very disruptive to yoursleep.
If you've got very little sleepreactivity, you may actually find itcomfortable, more comfortable to sleep with somebody in the same bed asyou.
I was thinking the other day because itwere, I've currently movedinto, there's no blinds or curtains in thebedroom.
And I was wondering if that might be a good thing because it at least means that in terms of my circadianrhythm, I'm waking up at the same time every day because I'm waking up when the sun comesup.
Yeah, but the sun comes up at different times on differentdays,firstly.
So if you were doing thatroutinely, you might find yourself really rather sleep deprived in the summermonths.
And also there is some emerging evidence that exposure to light at night in your sleep is not very good foryou.
So there was a very recent study that implied that light exposure at night increases your risk ofdiabetes.
So it certainly is not good for the quality of your sleep and the likelihood is that you won't wake up as soon as it'slight, you'll wake up at an hour or so after it's gotlight.
And you're ensuring that hour or so it may have had a negative impact on the quality of yoursleep.
So having a dark bedroom is really part of good sleep hygiene as it's having a quiet bedroom that is not too hot or toocold.
What if you wear a sleepmask?
Yes, itdoes. Imean, I wear a sleepmask.
I thinkit's, youknow, particularly if you don't have good blackout curtains or blinds in your bedroom using a sleepmask, particularly in the summer months is probably very helpfulindeed.
Does that mean that the only light receptors we have are behind oureyes?
Well, I think that there wasa, there were some rumors on the internet that there were light receptorselsewhere, but certainly the only ones that we know to be of significance in terms of defining or circadian rhythm are the ones in ourretinus.
Because I did psychology when I was in secondary school and I remember reading one of the psychologybooks, maybe my psychology teacher told methis, I think it wasMrs.
Lowney, that there were some studies where they shine the light like underneath someone'sknees.
Yes. And people would like wake up when they shine the lightsthere.
I think that that'sbeen, that's been very much discountednow.
It's a little bit strange though that the only light receptor would be behind theeyes.
It just feelslike, I don'tknow, feels like poordesign.
That there's only one place where we figure out if it's night orday.
So, so youknow, you seethat, forexample, in people who've lost theirsite.
Right.So, so in some individuals who have lost their sitecompletely, then they lose the regulation of their circadian rhythm and they develop circadian rhythmdisorders, something called a non-24-hour rhythm disorder whereby their circadian rhythm is ona, forexample, a 25-hourcycle.
And so every night they will go to bed one hour later than they did the previous night and will go right the way around theclock, youknow, every month orso.
So, youknow, that's a very good piece of evidence that actually it's those cells inthe, in the retina that are of crucial importance for maintaining the stability of our circadianrhythm.
I wrote thatdown. I've written in one recentstudy,40% of totally blind individuals had a non-24-hour circadianrhythm, which really kind of for me also highlights just how important it is to think about my circadian rhythm and how much impact it's having on my wholebody.
The other part you mentioned was the biological element to circadianrhythms, which people refer to ascoronatipes.
Yes. And this idea ofcoronatipes, which is essentially from myunderstanding, that genetically we all have a slight sort of disposition to sleep in at certaintimes, and to wake up at certaintimes.
Yeah. So there's thesenames,right?
There's like theowl, the lark or whateverelse.
I think I'm anowl, but that also could just be badhabits.
Yes.Yeah. So certainly there's that sort of geneticpredisposition.
There's also these environmentalfactors, but there's also age in the circadian rhythm changes a little bit as we go through different stages oflife.
So it's not at all uncommon for teenagers to become more eveningcoronatipes, and then as we getolder, we tend to shift back to themorning.
So that's part and parcel of our aging biology aswell.
So I think that genetics is reallyimportant, but so are other factors aswell.
Studies and twins suggest that up to50% of our coronatipes under geneticcontrol.
So does that suggest that we are likely to have a similar coronatip to ourfamily?
We are likelyto, but obviously our environment is not going to be exactly the same as our parentsare, youknow, what we do our behaviors are not going to be identical to our parents or oursiblings.
Soyes, we more frequently seethat, forexample, people have a evening coronatip that runs infamilies, but that doesn't meanthat, youknow,look, we're more than just the destiny of the genes that wehold.
Obviously our genes are reallyimportant, but so are other factors aswell.
If someone came to you and theysaid, I'm struggling with mysleep, youknow, multiple nights in arow, I haven't been able tosleep, I'm getting in bed and nothing's happening and then I'm waking up and I'm just sat there thinkingabout, youknow, sleeping and I feelhorrific.
Where would youstart? So I wouldstart, Ithink, by trying to understand what it is that is causing their sleepissues, because a lot of the individuals that I see who have been referred in with that sort ofpicture, assume that they've got insomnia and they may not always haveinsomnia.
I think a key issue is that we arereally, really poor witnesses to our ownsleep.
And what I mean by that is that we often are experience of sleep is very different to the reality ofsleep.
When we bring in people into the sleeplaboratory, it's not at allunusual.
And I will almost always ask this question when I'm going through a sleep study with one of my patients is how much sleep do you think you got over the course of thatnight.
And it's not at all unusual for people to say tome,well, I think I've got two or three hours sleepoccasionally, even theysay,well, I didn't sleep atall.
And then you look at their brainwaves, you look at the best objective marker that you've got of theirsleep.
And you see that they've slept seven and a half eighthours.
So obviously what people are experiencing is really important because ultimately from myperspective, I want to improve people's experience of their sleep and what it is that they're complainingof.
But it's important to understand that what they're telling you may not necessarily be the objectivetruth.
Now that's really important when it comes to insomnia because it's not unusual for me to see individualswho, youknow, they give you a story of very clearinsomnia.
And actually when you look at their sleepobjectively, you find that although they say they haven't slept atall, they've slept sevenhours, but that seven hours has been completely disrupted by conditions like periodic limb movementdisorder, which is these leg kicks associated with the rest of the legs syndrome or sleepapnea, forexample.
Now sometimes it's very evident from what people tell you that actually that's not the case that they've just got very clearinsomnia.
So that's really the starting point to try and decide whether or not you feel confident enough in your clinical evaluation of them that you know what the issue is without doing a sleepstudy.
And if you think that they do need a sleepstudy, then that's the point at which we are we are we arrange forthat.
It's also trying to understand some of the factors that might be driving their sleepdifficulties.
So forexample, was there were their sleep difficulties triggered by a lifeevent.
Did they have sleep reactivity before this insomniastarted?
Were they one of those individuals who could sleep anywhere at anytime, whatever theywanted, whenever they wanted to put their headdown, or were they kind of individual who the night before an exam before a job interview before a presentation would losesleep.
Because that often is a very strong marker for developing insomnia later on inlife.
And then it's also about trying to understand how the rest of their health is impacted by theirsleep, but also how the rest of their health impacts onsleep.
So it's not at all unusual for me to see individuals who have been started on medications for other reasons that have generated sleepissues, forexample.
You talked about this sort of obsession withsleep.
And I was wondering in the case of the patient you've justdescribed, would you encourage them to wear a sleeptracker?
So first ofall, I have to say that I'm not ideologically opposed to sleep trackers ingeneral.
I think that they arereally, reallygood, forexample, inresearch.
Fantastic forresearch.
It allows us to track sleep invery, very large numbers of individuals and try and work out how that correlates with whatever we're interestedin.
One of the major issues with sleep trackers is that the people who often use sleep trackers or individuals who already are concerned about theirsleep.
So if you know that you're sleeping relatively little and you wake up feelingtired, then you probably know you're not sleepingenough.
You don't necessarily need a sleep tracker to tell you that if you're one of these individuals who hasinsomnia, who is spending plenty of time inbed, but simply cannot get the amount of sleep that theyneed.
Then what a sleep tracker will do is it will increase yourconcern, your anxiety around yoursleep.
It's a very different picturefrom, forexample, using a steptracker.
If you're sitting on the sofa and you look at your step tracker and you realise you've only done whatever itis, 5,000steps.
It's very easy to get up and go for a walk and do another 5,000steps.
If your sleep tracker is telling you you slept really badly and you know you slept really badly and you're already worried about how badly yousleep, there's nothing that you can do on the basis of the information that your sleep tracker is giving you to suddenly go and get a little bit moresleep.
And it's complicated by the fact that sleep trackers are pretty good at telling you how much time you spent inbed.
They're reasonably good at telling you how quickly you dropped off tosleep.
Thereliability, the accuracy of thesedevices, most of these devices drops off significantly when it comesto, forexample, defining nighttimeawakenings, defining stages ofsleep, those kinds ofthings.
So then you have that additional issue in themix, which is that sometimes the sleep tracker may be giving you information that is not factually correct and that may increase your anxietyfurther.
So I'm reallyvery, very keen for people who have issues with their sleep rather than just burning the candle at both ends to put away their sleep tracker and actually go and have a chat with their GP or somebody who knows a little bit about sleep rather than relying on this sleep trackingtechnology.
Do you think sleep trackers have had a negative or positive impact on sleepculture?
I think that for those individuals who can fix their sleep in a very straightforward way by spending more time inbed.
So the kinds of people that I talked about the 20 years ago would besaying,well, youknow, I only sleep five hoursand, youknow, because I'm busy doingX, Y and Z and I can get away withit.
I think it's probably encouraged them to spend a bit more time in bed because they know they have a veryclear, very clear bit of information that's telling them that they're not sleepingenough.
But for the people that Isee, the people who are already concerned about their sleep and who have difficulties with theirsleep, I think it's been a very negativeimpact.
And I have some reservationsabout,well, people like myself sitting on these kinds of podcasts or writing and newspapers tellingyou,well, youknow, if you don't get enoughsleep, you're going to dieearly, you're going to have all these negative health consequences because for a subgroup of individuals who are already very concerned about their sleep that actually can causeproblems.
I have seen individualswho, forexample, have read books on sleep and how important it is onsleep, who have ended up going into a spiral of insomnia and very catastrophic depression and anxiety as aresult.
So it'svery, youknow, it's very important to be clear that all of this is a double edgedsword.
It's interesting with sleeptrackers.
I cansee, I think it's worth me saying that I am both an investor in WIP and I'm also sponsored byWIP, but I also agree with the things you'vesaid.
So I've seen this sort of variance in how a sleep tracker can improve some people's lives and it can make other people more anxious in a way that's nothelpful.
Forme, my sort of testimony on itis, I was one of those people you described earlier that thought sleep was take it alleither.
And when I started seeing a sleeptrack, it's kind of like that when I saw my brain for the firsttime, I did a brain scan and I didn't even kind of like realize it was there and I could influence it and that things I was doing without really thinkingmuch, we're having this bigimpact.
And forme, what it did is it allowed me to finally make this link between how much sleep I've had and then how Ibehave.
Now, I thought my behavior wasrandom, but seeing that when my sleep scores weredown, I was way moreemotional.
I was way more likely to eatcrap.
And the other thing that Isaw, which was reallyinteresting, was that when I had a glass of wine or two glasses ofwine, through glasses ofwine, that it just like a destroyed mysleep.
And I never knew that before and I was in search of reasons to quit alcoholanyway.
And when I sawthat, I quit alcoholforever.
So I've not dranksince.
So, and then forme, I have to alsosay, there are moments in my life where life happens and I know I'm not going to sleep and I don't pay attention to my sleeptracker.
But there are other moments where I have a bit more control and that's when I kind of tune into my sleeptracker.
I've also had parents message me a lot andsay,listen, I've got a one yearold, a two yearold, a three yearold,whatever.
There's no point in me wearing a sleep trackerbecause,listen, I'm not going to get any sleep and I also completely agree with them that there's really no point in thatsituation.
I think there's a point when there's something you can do aboutit.
That's absolutelykey.
So the point of doing anything like that is if there are very clear things that you can do on your own to close thatloop, there's no point having information without being able to act uponit.
I guess if you are one of those individuals like yourself who very clearly can correlate certain things that they're doing in their daytime lives with their sleep and how they feelsubsequently, thengreat.
I guess I have a little bit of bias in that the people that I see are already struggling with their sleepalready.
So itgoes, I guess we're completely inagreement.
It's so interesting because that's been a developing idea because obviously my bias is alwayslike, wouldn't you rather know becausethat's, youknow, but then from doing thispodcast, I've seen the comments and I've seen the struggle in from speaking to parents that struggling with their sleep and it's kind of sometimes just makes them feel worse aboutit.
I think nuance is necessary on thisissue.
And I'm sure there's a lot of things in my life that I wouldn't like to be able to track because either I don't have control of them right nowor, youknow, maybe they'd make me feel moreanxious.
There's this thing called the glimphatic system which I findreally, which when I discoveredthis, I really helped me to understand the importance ofsleep.
Can you explain what the glimphatic system is as if I was a 10 yearold?
Yeah, so within ourbodies, there is asystem, a very similar system called the glimphaticsystem.
So people will have heard of lymphnodes, forexample.
And this is a system whereby fluid that comes out of the blood vessels and into the tissues is then collected and transported back intothe, the cardiovascularsystem.
And we used to think that there was no equivalent system in thebrain, butactually, youknow, over the last 20years, we've understood that whilst there are no sort of lymph nodes or things likethat, there are these very small channels between the cells that are responsible for draining fluid from thebrain.
And those systems are responsible for removing certain toxins ormetabolites, chemicals that have built up as a result of metabolic activity within the brain and removing them from the brain substanceitself.
Now, it's like a carwash.
Like a drainagesystem, youknow, like a like agutter, forexample, youknow, that takes the suds from the car wash away and puts them into thedrain.
In about2011, if my memory serves mecorrect, there were some studies done that looked at that glimphatic system in different stages ofsleep.
And what they described was that that glimphatic system opens up significantly by about60% in very deep sleep in the deepest stages ofsleep.
Andso, and so subsequent research showedthat, forexample, one of the proteins that was being removed was a protein called B tramloid thatis, that is intimately tied to Alzheimer'sdisease.
And so the view that deep sleep was particularly responsible for housekeeping of the brain for chemical housekeeping of the brain cameabout.
And it gets a bit more complicated because actually only a two or three weeksago, another study suggested that that60% increase in the glimphatic system was not thecase.
And so I think that this remains an area that there is some uncertaintyabout.
Butactually, there are many reasons to tie in sleep ingeneral, separate from the glimphatic system into a general housekeeping role of thebrain.
And I think that certainly this is an area that is going to keep researchersvery, very busy over the next 10 or 20years, this association between sleep cognition and cognitive decline in laterlife.
That that protein that seems to spike if we are sleep deprived betaamyloid.
And that's linked to Alzheimer'sdisease.
So in Alzheimer'sdisease, we see beta amyloid deposition within the brain substanceitself.
What is depositionme? So it's deposited within thebrain.
If someone hasAlzheimer's, they have a sort of these build a build up of a build up ofB.
So there is some evidence to suggest that both chronic sleep deprivation and insomnia are associated with cognitive decline and conditions likedementia.
It goes back to what I was sayingearlier, which is by theway, there's also some studies that have suggested links between sleeping tablets and conditions likeAlzheimer's.
So it goes back to this issue of whether or not it's the insomnia or the sleep deprivation that causesAlzheimer's.
Is it sleeping tablets that causes Alzheimer's or is it the fact that Alzheimer'smany, many years before causes changes to oursleep?
And so I think that that story has not yet come to fruition in terms of our fundamental understanding of the links between sleep and Alzheimer's disease and whether or not it's directlycausative.
Do you recommend slash are you a fan of you reference sleeptablets, the sleep medicinemedication?
Yeah, so as a generalknow, because I think that there are good now non drug based techniques for trying to improve sleep in the majority of people withinsomnia.
There is some evidence that forexample, if people don't respond to these non drug based methods giving them sleeping tablets alongside these non drug based methods makes it more likely for the psychological route tohelp.
But youknow, unfortunately as part of my clinicalpractice, I see lots of people who've been struggling with a sleep formany, many years and they've tried all non drug basedtreatments.
And the risks of them sleeping so little in terms of theirmood, theiranxiety, their ability to function are so great that actually you have on a case by case basis to make a judgment call as to whether or not tosay,well, I give up on your sleep or actually yousay, welllook, there are a number of drugs that we can try to try and improve yoursleep.
And it's not going to get you back tonormal, but it's going to potentially make the difference betweenyou, youknow, end up very depressed or highly anxious and unable to cope in your life or actually get some decentsleep.
And the risks of those drugs and that needs to be judged on a case by case basis and it's part of clinicalmedicine.
Whenever we prescribe any medication for anybody for anycondition, we have to evaluate what the potential benefits are versus the potentialrisks.
A lot of people seem to be taking melatonintablets.
Is thathealthy? Is that free from sideeffects?
So it's not entirely free of sideeffects, but it's generally pretty well tororated safe drug as far as weknow.
There are some specific issues surroundingmelatonin.
But a question really would have tobe,well, why are you taking thatmelatonin?
Is there something that you can do to fix your sleep without relying on an exogenoussubstance, something that you've bought off the shelf or beingprescribed?
Is my hesitation and reservation with taking things like melatonin is always that I just assume that my body will become a little bit reliant onit.
Yeah, I think whether you becomephysiologically, biologically reliant upon it or psychologically reliant upon it remainsunanswered.
But certainly that there are individualswho, forexample,say,well, as long as I know that I've got a bottle of melatonin or the sleeping tablets in my bedsidecabinet, I sleepfine.
As soon as I know that I haven't got access tothem, I don't sleep very well atall.
And so that I think exhibits that this is almost like a psychological crutch knowing something that they've got next to their bed that they can reach for in order to achieve a good night's sleep is sometimes as important as the biological effects of taking thattablet.
Imean, that kind of leads to the non medical techniques to improve oursleep.
So you said typically with someone that comes to your sleep center instead of going straight to medication as the answer to their sleepissues, you would suggest and or try non medicalinterventions.
Yes. And you said that these workwell.
Yes. What are these non medicalinterventions?
So the gold standard treatment now for insomnia is a treatment called cognitive behavioral therapy forinsomnia.
So a lot of people have heard of CBT because they will have heard of it in the context of depression and treatment of depression oranxiety.
Now CBT for insomnia is not actually directly related to the CBT that's used for depression andanxiety.
It borrows from the principles of CBT and applies them tosleep.
It serves twopurposes.
The first is to try and address some of those conscious psychological factors that are drivinginsomnia.
And when I talk about consciousfactors, I'm talking about things like the frustration or anxiety of the night ahead of lying in bed at night feeling that you can't get off to sleep and the frustration and anxiety that that engenders of having your partner snoring away in bed next to you whilst you're struggling to go off tosleep.
And you're struggling to get off to sleep and anxiety of worrying about how you're going to be able to function the following day or potentially even the long term effects of yourinsomnia.
So those are the conscious psychological factors and CBT aims to addressthose.
But it also aims to restore normal unconscious factors that give rise to goodsleep.
And then a great deal of time in bed at nightawake.
Then those normal associations that good sleepers have between bed andsleep.
So for a goodsleeper, they will associate bed with being a place ofcomfort, with being acalming, relaxingplace, a place that they associate with a good night'ssleep.
If your sleep has been disrupted for a period of time and you've spent long periods of time in bedawake, then that positive association between bed and sleep is replaced by negativeassociation.
So you begin on a unconsciousbasis, patholovianconditioning, it'scalled.
You associate that bed environment with beingawake, with beingwired.
And that's often what gives rise to this sensation of having lost the switch to be able to get off tosleep.
Infact, some people within insomnia willsay,well,look, youknow, if I'm sitting in front of the television and I'm sitting on the sofa and I'm not thinking about sleep atall, I'm not thinking aboutbed.
I will often find that I've dosedoff.
And then I'll goupstairs, get into bed and as soon as my head hits apillow,ping, I'm wide awake and I suddenly feelwired.
So that's very illustrative of that sort of unconscious association between bed and beingawake, rather than beingasleep.
And so CBTR aims to address that aswell.
How doesit? How does it dothat?
So it uses a variety of differenttechniques.
So it uses some standard sort of relaxation techniques to try and reduce the level of vigilance of physiological of mental arousal that you have when you get off tobed.
But also it aims to utilize a variety of techniques to reprogram your brain to associate bed withsleep.
So one of the ways in which you can do that is you can actually utilize your brain's own mechanisms that drive you to go off tosleep.
So that's something called the homeostaticmechanism, which will all be very familiarwith, but not in thoseterms.
So the more you've beenawake, the stronger the chemical drive for your brain to go off tosleep.
So one of the features of CBTR is to compress your sleep or to restrict your sleep for a period oftime.
Essentially what that meansis,well, if you are an in somebody withinSomalia, and youestimate, forexample, that you're only sleeping a total of six hours a night inbed, but you're spending eight hours a night inbed, then you for a period of time yousay,well,look, I want you to get into bed at midnight and whateverhappens.
I want you to get out of bed at 6a.m.
So to restrict the time in bed to sixhours.
So the first fewnights, most people within Somalia will sleep really badly because they know that their alarm is going off at six and they know they have to getoff.
Get out of bed atsix. But after a littlewhile, they become so sleep deprived that the brain starts forcing you to go off to sleep much morequickly.
And overtime, more and more of that six hours a night will be spent asleep inbed.
And that's the first step in breaking that negative association between bed and wake and rebuilding a positive association between bed andsleep.
Imean, at itsextreme, there is a technique that was developed inAustralia, which is called intensive sleepretraining.
And in thattechnique, people who've got very bad in Somalia are brought into sleep laboratory having been awake for the night before they comein.
In theevening, having been awake fornow, probably 36hours, every half anhour, they're given the opportunity to drop off tosleep.
They have some wires on theirheads, their brain waves are beingtracked.
But as soon as they've been asleep for threeminutes, based on their brainwaves, they're woken upagain.
And that happens every half hour for 25hours.
So over the course of that 25 hourperiod, they have 50 opportunities to nap now for most people within Somalia having beenawake, even having been awake the previous 26hours, they will still not be able to get off to sleep for the first fewnaps.
But as they get more and more sleepdeprived, every time they're given the opportunity to drop off tosleep, they will start falling asleep morequickly.
And at the end of that 15apps, they will be dropping off to sleep very quickly as soon as the lights gooff.
Andactually, the evidence suggests that that's a very good short term treatment for chronicinsomnia.
And in someindividuals, it works extremely well in re-associating your head hitting the pillow with drifting off tosleep.
I wouldn't suggest it for most people because it's basically a form oftorture, but I think it illustrates the power of trying to get people into a more sleep deprived state if they've gotinsomnia.
It's interesting because much of what you've said makes me think that we all have our own sleepidentity.
And when I say sleepidentity, Imean, a story we tell ourselves about our relationship withsleep.
And it makes me think that our sleep identity is much more powerful than I think wethink.
Because if you speak toanybody, anybody in this roomupstairs,wherever, and yousay, what do you likesleeping, they will deliver their sleepidentity.
They'llsay, I'm a badsleeper.
And I wonder how much of that is selffulfilling.
Because I think I've always told myself that I'm a goodsleeper.
Andtherefore, I find sleepeasy.
And I've got friends who willsay, I'm a really badsleeper.
And I'm wondering how much that's impacting their ability to sleep and or if they even knowobjectively, if they are actually a good or badsleeper.
It's just this identity we'veembodied.
Do you see that alot? Do you see that someone's sleep identity kind of determines how they actuallysleep?
I think all of that is trueundoubtedly.
And I think this comes back to the earlier bit of our conversation about sleep trackers because obviously sleep trackers reinforce that sleepidentity.
Whether they are100% accurate ornot.
And soyes, that would that sort of sleep identity would undoubtedly influence both those conscious and unconscious factors that give rise tosleep.
If you're a good sleeper and you've always been a goodsleeper, you don't worry about any of thesethings.
You probably don't even worry about any aspects of sleephygiene.
Youknow, I'm quitehappy.
Youknow, like you watch a horror movie in bed before you drift off tosleep.
But for those individuals who are who arenot.
Yes, absolutely that the way that you view sleep and your relationship with sleep is of fundamentalimportance.
It is again coming back togenes.
We know that there are undoubtedly genetic factors that influence whether or not you're likely to developinsomnia.
Soagain, as with all aspects ofsleep, it's that combination of geneticsenvironment.
And when I talk aboutenvironment, I'm also talking about your own psychological internalenvironment.
I am the other thing I think we talked about sleep happening earlieron, but it seems that a lot of people believe they have a deviated septum is it called deviatedseptum?
Septum,yeah.Yeah,septum.
I've heard some people say that that's the reason that they can't sleep and they've gone off to get surgery to kind of correct the deviatedseptum.
What's your thoughts onthat?
Is that is thattrue? Because I wonder how I'mlike, do we can't all be being born broken with these deviated septums orwhatever?
I think it's normal for us to have some asymmetry in ournoses.
And a lot of people have a deviatedseptum.
Septum is a result of having broken theirnose, forexample.
Youknow, I'm a little bit suspicious about operations for that kind ofthing.
Unless there are very clear abnormalities that might be responsible for sleepingpoorly.
So one of the majorissues, forexample, in sleepamniaries, sleepamni, the obstruction is in thethroat.
It's not in thenose. And so issues with nasal congestion or difficulty breathing through the nose do not directly cause obstructive sleepamni.
What they can do in some individuals is they can encourage them to people to breathe through their mouth and breathe with their mouthsopen, which alters the position of the jaw and can create a bit more narrowing in the back of thethroat.
So for some individuals who have very prominent nasal congestion at night and who have evidence of sleepamni, sorting out their nasal congestion and correcting a deviated septum maybe one way of doingthat, there is undoubtedly irrational for sorting themout.
I think that there are probably quite a few individuals who are having unnecessaryoperations.
Makessense. So we've got the cognitive behavioral therapy for insomnia as onecure.
We've got that extreme torch therapy that they did inAustralia.
Yeah, we've got melatoninmagnesium.
People have mentionedmagnesium.
So anecdotally magnesium can help someindividuals.
And anecdotally also magnesium is a very good treatment as testified to by some of my patients for conditions like restless legsyndrome.
So restless leg syndrome is this sort of neurological disorder wherebypeople, and it's often associated with things like pregnancy or low-onlevels, but it's under genetic control aswell.
People experience a number of differentthings.
So the first thing is that they get an urge to move atnight, and it's typically a night rather than during theday, often associated with unpleasantsensations, that if they try and keep still that sensation builds and builds and builds until they have tomove, that if they domove, they get some transientrelief, and it's often associated with kicking at night in yoursleep.
It's verycommon, very common inpregnancy, very common in people who areanemic, and in people who've got problems with theirkidneys, but it's common in the general population aswell.
And so for people with restless legsyndrome, magnesium does sometimes helpsignificantly.
And what's it doing is relaxing aswell?
I don't think we actually know precisely what it'sdoing.
When you look at an under-slappedbrain, so if I was sleepdeprived, what would the difference in my regular sleep activitybe?
What would yousee? Would you see my brain is notactive?
Would you see part of it notactive?
So we would see on a grosslevel, on a sort of macrolevel, we would see that your brain is prioritising very deep sleep over other stages ofsleep, atnight.
During theday, if you were chronically sleepdeprived, using the techniques that we use in clinicalpractice, you would see verylittle.
There is some increasing evidence that actually what is happening within our brains is that we are constantly showing little areas of our cerebralcortex, the outer lining of ourbrain, the bit of the brain that's responsible for our cognitiveabilities, forexample, that dip it in and out of electricalsilence, what has been termed localsleep, so that there are little islands of local sleep that are constantly occurring over our cerebralcortex, whilst we'reawake.
And as we get more and more sleepdeprived, and depending on how much we've used that particular bit of ourbrain, those islands tend to get slightlylonger, the periods of silence getlonger, and those islands become morewidespread.
So we'reconstantly, even with you and I aretalking, there are little areas of our brain that are constantly dipping in and out ofsleep.
But if we're very sleepdeprived, actually that electrical silence of our cerebral cortex gets more extensive and morewidespread, which is probablywhy, or at least one of the reasons why we decline from a cognitive perspective when we are very sleepdeprived.
Okay, somy,okay,interesting, becauseokay, so different little parts of my brain are doing little micro-sleeps if I'm sleepdeprived.
Yes. Andthat, from a behavioralstandpoint, will show up in my day-to-day lifeas, worst cognitiveperformance, maybe lessfocus.
Arethere, because I've always wondered why on an unsleptday, I feel like I'm moreemotional.
Youknow, people say they're a test of the fact that if someone's a little bitcranky, theythink, are they probably not slept lastnight?
There's that phrase and they'relike, who woke up on the wrong side of thebed,etc.
Is there a scientific basis forthat?
So I don't think we can fully explainit.
I think that there are certainly the areas of the brain that are responsible for emotion and emotional cognition are more metabolicallyactive, and so maybe more vulnerable to the effects of sleepdeprivation.
I thinkwe, it is likely that when you're sleepdeprived, there are some changes in terms of certain neurotransmitters within the brain that may exacerbatethat.
But what'svery, very clear is that that association betweensleep,mood, anxiety levels isvery, veryclear, and in fact we seethat, forexample, in people with clinically significant anxiety or clinically significantdepression, that actually treating anxiety or depression in somebody who is sleep deprived or has insomnia as much moredifficult, that treating the insomnia or somebody who is anxious or depressed is much more difficult without addressing the anxiety anddepression.
This is reallysignificant, not just on a day-to-day basis for all ofus, but also in clinical medicine and clinicalpsychiatry.
So jumping back to the point about when we're under-sled certain parts of our brain are doing littlemicro-sleeps, it is fair to say that the phrase that we're halfasleep, there's some merit tothat.
We may not be halfasleep, but we could be a thousandths of sleep or a hundredth ofsleep.
And this idea that the brain can exist in different stages of sleep or wake at the sametime, by theway, also extends to thenighttime.
So forexample, in people whosleepwalk, who do really rather dramaticthings, and I've seenpatients, forexample, who've driven in theirsleep, one patient who rode a motorbike in hersleep, I've seen people do some incredibly complicated things like cooking a meal in theirsleep.
All of these sleepwalking type events relate to the fact that certain parts of the brain are in very deepsleep, whereas other parts of the brain actually demonstrate wakingactivity.
So the bits of the brain that are remain asleep are the frontallobes, which are basically where our rationalthinking, where our decision-makingoccurs, and the parts of the brain that are responsible for memory are part of the brain calledhippocampus.
Whereas actually in theseevents, there are other areas of the brain like the areas responsible for movement or vision oremotion, demonstrate waking activity both on an electricalbasis, but also on a metabolic basis aswell.
Why do wedream? It's a bigquestion, isn'tit?
That's such a bigquestion.
The short answeris, I think we still don'tknow.
I think there are lots and lots of theories about why we dream that those range from dreaming sleep being fundamental formemory, for reinforcingmemories, for regulation of our emotionalmemories.
I think you've had Matthew Walker on previously who probably talked about this view that dreaming sleep is emotionalrehabilitation, form of emotionaltherapy.
One of the unanswered questionsis, forexample, why when we are born or when we're in our mother'swomb, we spend the third of our lives in REMsleep.
Andyet, that drops off significantly as we get older to the point where by the time we areelderly, we're doing very little REM sleep at allovernight.
So this rapid decline in the proportion and the amount of REM sleep that we are exhibiting has been explained by some individuals as it being fundamental to the development ofconsciousness, forexample.
So there's a chap calledHobson, who is based in one of the Ivy League colleges in the states who was very keen on this idea that REM sleep is part of the early development of consciousness as we are inside ourmothers.
We're inside our mothers womb and maybe fundamental subsequently to learning newthings, to learning new motortasks.
The honest answer is I think that there's probably more than onefunction, if that many functions of REMsleep.
So REM sleep is the stage of sleep where we where we start to dreamright.
So REM sleep is the stage of sleep that we most associate with dreaming and it's the stage of sleep that is most associated with dreams of a narrativestructure.
So these kind of stories thatevolve, that have aplot.
But actually we know that lots of people dream in non REM sleep aswell.
And then you can see thatin, forexample, people who sleepwalk or have nightterrors, they will often very clearly be able to rememberdreams.
But those events will have arisen from very deep non REMsleep.
So we do dream in other stages aswell.
It feels like it's not a great evolutionary trait to havenightmares.
I can't understand the basis of having a nightmare and why that's a goodthing.
Youknow, I'm not sure that that we're evolutionally driven to havenightmares.
I think that what nightmares represent is the fact that we've had these kind of mentalexperiences, but we've woken up to the extent that that nightmare has never beencompleted.
Because usually we forget ourdreams.
Youknow, we all almost all of us go through four or five cycles of REM sleep anight.
And so we're probably having dreams throughout thenight.
But youknow, most of us don't remember the vast majority of ourdreams.
We remember the dreams whereby we've woken directly out of REMsleep.
Why isthat? Why do we remember the dream when we wakeup?
I think that's another unansweredquestion, but it's quite clear that that rapid transition between REM sleep and wake means that the memory of whatever it is that we've been experiencing has not been fully cleansed has not beenremoved.
Now, that goes back to Matthew Walker's theory of REM of dreaming as an emotional therapy because youknow, the argument is that if you've experienced something that is so strongly driven byemotion, youknow, you've had a very traumaticexperience.
Then one of the things that one of the reasons why you don't recover from that is because you are when you're dreaming about thatevent, you will invariably wake up because the emotional content of that dream is sohigh.
Which is why these kind of recurrent nightmares are part and parcel of post traumatic stressdisorder.
You're never completing thatprocess.
And you're never allowing yourself to achieve emotional recovery from that originaltrauma.
So, so one could argue under the theory that our dreams are therapy that it's our like subconscious mind playing through the scenario in order to maybe better understand it and process it and to come to peace with what happened maybe learn fromit.
Youknow, from an evolutionaryperspective,okay, so if you've had a traumatic event say you were attacked by alion, youknow, out in out in thewilds, then obviously having avery, very strong emotional association with the terror of being attacked by a lion is very important for you to avoid that again and to learn from thatevent.
But what you don't want is you don't want the next time you see that lion to have such an strong emotional response to it that you can't do anything about it that you that you freeze has that's not very good for yoursurvival.
So, you want to learn from these very strong emotionalevents, but you don't want that emotion to be heightened to the same extent that it was during that originalexperience.
So, from an evolutionaryperspective, there is some rationale tothat.
What's the most upsetting case of a sleep disorder that you've everseen?
Imean, I've seen a lot of very upsettingcases, youknow, I've seen individuals who have committed crimes in theirsleep.
Really?Yeah, I was involved with somebody who not in theUK, I wouldstress, who shot a family member in theirsleep.
I've seen individuals who have committed sexual assault in theirsleep.
Butalso,yes, somebody who was convicted for rape as a result of a sleepdisorder.
Now,obviously, youknow, one of the great difficulties is that you can never be absolutely sure whether during that particular episode they were in there that that occurred during their sleepdisorder.
But what you can certainly say with a degree of certainty is that there is clear evidence that they have exhibited similar things that have definitively occurred out of theirsleep.
Butalso, some of the effects of these sleep disorders on people's lives is reallydramatic.
So, I look after a large number of individuals with a condition called Cline Levinsyndrome, which is a very poorly understood condition often affects young kids andteenagers.
And they will gothrough, there'll be fairly normal betweenepisodes.
And then duringepisodes, they will be profoundlysleepy, sometimes sleeping23, 24 hours aday, when they'reawake, they're veryconfused, they exhibit very abnormalbehavior, eatingbehavior, sexualbehavior.
And that can last four days or weeks out of theblue, which can have a massive impact on people'seducation, people's sociallives, youknow, how they're managing in theworkplace.
So, these sorts of conditions can devastate people'slives.
In the case of the person that killed somebody while they wereasleep, did they get convicted of thatcrime?
That is still inprocess, as Isaid, it's not in theUK, which is why I'm mentioningit.
But, youknow, there have been many examples of individuals who have been found not guilty as a result of acrime, includingmurder, having occurred in theirsleep.
Now, as Isaid, there is always a degree of uncertainty as to whether or not a particular event happened insleep, but what in those individuals we can say is that there are many individuals who exhibit similar sorts of patterns of behavior that have been clearly demonstrated to arise fromsleep.
What do you have to demonstrate in orderto, when that goes tocourt, what are they lookingat?
Are they looking at your past sleepbehavior?
Do they put you in a sleep laboratory andcheck?
I think both of thosethings.
So, youknow, first ofall, is past behavior consistent with what has happened on that night inquestion?
Secondly, are there any features about the event itself that suggests that there was an attemptto, forexample, cover it up or a degree of pre-planning in order to commit that particularact?
And also whether or not there can be evidence found by studying that individual sleep that they suffer from these kinds of sleepdisorders.
I read about the famous example of KennethParks, which is prettyunimaginable.
Yes. What is the story of KennethParks?
Kenneth Parks was a chap who was based in Ontario who apparently in his sleep drove several miles to his parents in law'shouse.
23kilometres. He was along, long way and apparently got a tyre iron out of the boot of hiscar, bloodshed his mother-in-law to death and then tried to kill his father-in-law and ended up throwing him into a swimmingpool.
Itwas, this was made even more curious by the fact that there had been some evidence that he'd been having some financial difficulties and had had some discussions with his parents in law about financialissues.
But it was deemed by a court of law that this happened whilst he was sleepwalking and he was actuallyacquitted.
So this is a remarkablestory.
Now, is it impossible for somebody to drive in theirsleep?
No, I've seen itmyself.
It seems stretching credibility that somebody could have undertaken all of that whilstsleeping, but in the court of law he was found notguilty.
That'scrazy. Have you ever seen someone drive miles in theirsleep?
Yes, youknow, I've got a patient who I don't seeanymore, who I mention in mybook, who has driven several miles in her sleep and in fact has driven a motorbike in her youth in hersleep.
And the only knowledge that she had was her land lady at the timesaid, were you going at one o'clock in the morning clutching your motorcycle orhelmet?
And she'd obviously been for a ride in the middle of the night without anyrecollection.
I think this goes back to what we were talkingabout, whichis, youknow, are we half asleep or we're 100th asleep or we're 1000sasleep.
So in those kinds ofsituations, it's likely that actually the majority of the brain is probably awake because it's very hard to envisage how somebody may be able to do something quite so complicated when the majority of their brain isasleep.
Butcrucially, the parts of the brain that remain asleep are the bits that are responsible for rationalthinking.
Imean, why would she have gone for a motorcycle ride in the middle of the night if she was thinking rationally and also the bits of the brain that responsible formemory?
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What proportion of people thatare, because there's various types of insomnia isn'tthere.
There's not just one type ofinsomnia.
I read about this sort of short sleep durationinsomnia.
And then in other insomniacs where they might be in bed for eight hours and sleep forhours, but they're not getting sufficient restorativesleep.
Is thatit? So we knowthat, youknow, and going back to what I was saying about us being poor witnesses to oursleep, the majority of individuals who have insomnia subjective insomnia when you bring them into a sleeplab, they may be sleeping slightly shorter than normal based upon tracking of their brainwaves.
But probably don't sleep a huge amount less than normalindividuals.
It's their subjective experience of sleep that is impacted rather than the true duration of theirsleep.
Those make up the majority of individuals withininsomnia.
But there is a subgroup of individuals whosay,well, youknow, I sleep four hours a night or three hours anight.
And they really do only sleep two or three hours anight.
Now in those individuals who kind of have the feeling that they are sleeping verylittle.
What we are actually beginning to understand is that there are some again some local changes in the way that the brain acts so that there are areas of thebrain, forexample, that might be responsible for awareness that don't switch off to the same extent at the rest of thebrain.
So whilst the majority of the brain may besleeping, those little areas of the brain that are responsible for our awareness at night for what's going on in our environment may not be switching off to quite the sameextent.
And so there's a sort of huge spectrum of what insomnia actuallyis.
What hope would you offer insomnia insomniacs because you know this video is going to draw in a lot ofinsomnia.
It always does whenever we talk about sleeps when I look at the comments and the feedback and thereviews,etc.
And it seems that insomnia acts converge here looking foranswers.
So I would say that the odds are in your favor that there are some very effective treatments forinsomnia.
That it's not always straightforward because insomnia interacts with a whole range of other conditions that may be affectingyou, like yourmood, like your anxietylevels, like what's happened in yourpast.
And sometimes it requires a multi-prongedapproach.
But for the majority of individuals we can make sleepbetter.
One of the real big issues that a lot of people are seeking for rapid or instant answers to theirinsomnia, which is why a lot of people end up ondrugs.
That may not necessarily be the right approach foryou.
And I would really count on it as the treatment of an insomnia can in some individuals take sometime.
And it's important to have a degree of patience to try and fix this in the long term rather than to provide a short termsolution.
What sort of percentage of insomnia actually thinkrecover?
Well, I think that if you extrapolate on the basis ofCBT, CBT-basedapproaches, we know that helps about80% ofindividuals.
Really?80%?Yeah, I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
I think that's a bigproblem.
So one of the individuals in that book is an individual who is not apatient.
It doesn't have anything wrong withhim.
He's got a condition calledsynesthesia, which is themelding, the combining of certainsensors.
So when he sees objects or he hearsobjects, he gets a taste associated withthem.
So he gives a really good example ofhis, youknow, inchildhood, his friend had a girlfriend whose particular name in him gave him a awfultaste.
And every time his friend mentioned this girl'sname, his mouth was filled with a terribletaste.
So he will readwords, he will hearwords, and all of those words will be associated with a particular taste that has lasted his entire life and it's been veryfixed.
So as akid, when he startedreading, he learned how to read by looking at the tube map on the way toschool.
And each of those tube stations has got a particular taste associated withit.
And that taste has remained fixed throughout hislife.
Now this sounds really verystrange, but actually we know that some degree ofsynesthesia, some degree of melding of our sensors is actually quitecommon.
That up to about4% of individuals exhibit some form ofsynesthesia.
And itreally, Ithink, illustrates how in all ofus, our minds and our brains and our nervous systems working slightly different ways to define ourreality.
And it's an exploration of how our nervous system can influence how we perceive reality to be and that truth may not always be what weperceive.
There's another patient inthat, not apatient, another woman in that book who hassynesthesia, she's amusician.
And when she playsmusic, she will see colors washing in and out of hervision.
And so forher, every time she hears a piece of music that will be accompanied by a visualphenomenon, sometimes even a sensoryphenomenon.
So certain pieces of music or certain sounds will precipitate certain sensoryexperiences.
I've oftenheard, youknow, hear about rain man and various types of autism where these sort of apparent geniuses say that theysee, what do theysay?
They say they do maths with like shapes in theirbrain.
If you ask them what 4 plus 4is, they describe that it kind of appears in front of them as ashape.
Yes. So that is a form ofsynesthesia.
And we know that synesthesia is much more common in people with autistic spectrum disorder than it is in individuals without neurodevelopmentaldisorders.
What does this tell us about the nature of ourexperience?
For someone that's not living withsynesthesia, does it mean that there is no such thing astruth?
I think what it tells us is that ourreality, what we perceive truth tobe, is intimately linked with the structure and the function of ourbrain.
And whilst we all assume that people's experiences of theworld, and by theway, the way that we interpret those experiences of the world are allidentical, that is very far from thetruth.
And I think it gives us someinsight, given the fact that how we perceive reality even in the context of an entirely normal and entirely functioning nervoussystem, is so predicated upon ourexperiences, is so predicated on our model of theworld, that the brain works as a predictionsystem.
So it works by assessing whether or not our senses are telling us or in keeping with what our expectation of the worldis.
So we need a model of the world as we understandit.
And that model of the world is influenced by ourexperiences, by ourgenes, by the structure and function of ourbrain.
So it's not necessarilysurprising, given that we all have very different experiences inlife, that we have differentgenes, that we will have gone through differentthings, that our truth may be very different from the truth ofothers, and that ourexperiences, our perceptions of the reality of theworld, may be verydifferent.
It kind of explains why there's a lot of polarization and a lot of conflict to somedegree.
I think itdoes. I think you only need to have a look on Twitter to see howdifferently, different people perceive exactly the samesituation.
But also one might argue that if there's people who have entirely different perceptions of the world because of their brain and their nervoussystem, that maybe they're not guilty of crimes that they'vecommitted.
Well, I think that's the subject of the thirdbook.
Yeah, seven deadlysins, the biology of beinghuman.
I had this debate with my friend the otherday, because I was reading about somestudies.
I think it was a study that showed a guy with a brain tumor had gone outsuddenly.
He was like a normalteacher, and he'd gone out and committed somehorrific, horrificcrimes.
And when they removed the brain tumor from hishead, he stopped committing all thesecrimes.
And so the question becomeslike, is this person to blame for thesecrimes?
But then you could obviously stretch that out further and justgo, when people are serial killersoftentimes, we find that there's something in theirbrain, or there's some earlytrauma, or there's some neurological issue that they'vehad.
So are theyguilty?Well,indeed.
And that's a really importantquestion, which is how much free will do all of ushave?
If we are all essentially machines that are doing the bidding of ourbrains, then anything that affects our brain function defines ourbehaviour.
And the book that is out in November very much discusses the neurological and psychological conditions that can influence our behaviour in really rather dramaticways.
Youknow, bethat, youknow, from the perspective of gluttony or wroth or pride or any of the other seven deadlysins.
Why did you write thisbook?
Thisbook, seven deadlysins.
Because it again reflects some of my clinical practice that I see individuals who have brain conditions that dramatically influence theirbehaviour.
Now the question in always in my mindis,well,firstly, does this reflect their ownmorality?
And it's quite clear that in those individuals itdoesn't.
But what are the implications for all ofus?
And as you alreadysaid, youknow, if that is the casefor, if a brain tumor can suddenly cause a dramatic change inbehaviour, if a strokecan, if Parkinson's diseasecan, if a chemicalchange, and some of the people that I detail in the book are individuals who are very similar to patients in mind in whom I'vestarted, an anti-aplecticdrug, forexample, exhibit a dramatic change in theirbehaviour.
And so a simple chemical taken in tablet form can result in those changes ofbehaviour.
What about all ofus? Are there things in ourenvironment?
Are there things that we are doing that influence the machinations of ourbrains?
So do these kinds of behaviours then take a moral viewpoint or should we be looking at them from a biological perspective rather than a moralone?
Give me one such extreme behaviour where you've seen some kind of chemical intervention or other intervention completely eradicate thatbehaviour.
So I've certainly seen a lot ofindividuals, so I said at the start that one of the specialist clinics I do is an epilepsyclinic.
And there are anti-aplectic drugs that are well known in a very small proportion of individuals to cause a dramatic increase inirritability, anger andaggression.
And I remember one of the earliest patients that I saw started on this drug was a very frail little old lady who must have been in her 70s and who was arrested by six police officers in her front garden being pinned down because she was so violent andaggressive.
So that's oneexample. Lots of patientswho, forexample, exhibit behavioural change after aseizure.
I've seen individuals who have had autoimmune conditions at their brain who have become franklypsychotic, youknow, ripping sinks off the wall in their hospitalroom, trashing their hospitalroom, attacking theirnurses, whoactually, when that condition istreated, they've reverted tonormality.
And in the case of the very angry grandmother who was kicking off at the police was she cured of thatbehaviour?
The drug was stopped and she returned tonormal.
The drug wasstopped?Yes.
So itwas...Oh, you took her off the anti-aplectic drug and replaced it with another and shenormalized.
Of all the extreme cases you've seen throughout your work and through these books you've written about sleep and the seven deadly sins and the man who tastedwords, what is the mostsurprising, crazy story that you'veencountered?
That show just how extreme and bizarre the human brain canbe?
So I think probably the one that sits with me in the most emotional way is probably a young man that I met who has never been able to feel pain throughout his entire life from the moment that he wasborn.
And infact, he has a genetic disorder that was also inherited by two of his siblings and none of the three children have ever been able to experiencepain.
Now at first glance you kind ofthink,oh, that might be quitenice, never to experiencepain.
But meeting somebody like that and you realise quite how important pain is for our normaldevelopment, for our normallives.
Youknow, he tells stories of him and his sisters essentially holding their hands up to the fart to hear the sizzling of their hands because they thought it wasfunny.
They didn't feel anypain.
They, he would regularly jump off the roof of his garage in order to get attention because he knew that if he broke a limb he would end up in hospital being looked after by these nicenurses.
And there was no downside toit.
Yet he is now terribly physicallyscarred.
It doesn'treally, youknow, he has no comprehension of what painis.
So there is that disconnect between the human experience ofpain, which is common to all of us and what heexperiences.
And I think that he feels that that is very much a barrier between him and understanding all the people aroundhim.
But it's also resulted in him being terribly damaged by the inability to feelpain.
Gosh, it really does perfectly highlight the role ofpain.
Very muchso. Something all of us think we'd rather livewithout.
Yes. And then you see somebody who has never experienced pain and see the impact it has onthem.
I think it makes you appreciate it in a slightly differentway.
Is there anything elsepain?
Oh,load. Imean, somuch, youknow.
Thereare, youknow, one woman who lost her vision as a result of multiple operations to her eye who sees visual hallucinations everywhere shegoes.
Youknow, I think that very much illustrates the fact that ourbrain, even when it's starved ofinputs, creates its own inputs because it's so eager to experience theworld, youknow, individuals inwhom.
Is sheokay? What's herexperience?
So she has lost her visionentirely.
And sees sometimes rather scary hallucinations as a result of that loss ofvision.
Youknow, what's really fascinating about her is that when she was asked by a doctor whether or not she would want those treated because there are some things that we can do to try and improvethose.
She had to think very long and hard about it because shesaid,look, youknow, at least I'm seeing somethingnow, whether that is real ornot.
There is a comfort to seeing something and in the end decided that she didn't want ittreated.
She'd rather live with thehallucinations.
What else are herinteractions?
So individuals who have lost their sense of smell or lost their sense oftaste.
Now, youknow, you kind ofthink,well, I could live without my sense ofsmell.
Probably it wouldn't be as quite a ritual that Iwould, as I wouldlike.
But actually the implications of losing your sense of smell both in terms ofmemory.
Youknow, you think how important smell is for memory for those sort of emotional memories that wehave.
Youknow, smelling your mother's perfume or a particular meal and taking you back directly tochildhood.
And the impact of smell on emotion on yourmood,on, youknow, depression is really underappreciated until you look at individuals who have lost their sense ofsmell.
And that was particularly important over COVID because a lot of people were losing their sense of smell as part of COVID and didn't know whether or not they would ever get their sense of smellback.
So all of oursenses... And they weredepressed,often.
They weredepressed.And, youknow, it is very clearly associated with changes inmood.
Smell and mood are very closelylinked.
And, youknow, if you think about some of the othersenses, sohearing, so people who experience auditoryhallucinations,or, youknow, in the man who tastedwords, actually I was verykindly, Bill Odie agreed to talk to me and Bill has been experiencing musical hallucinations formany, manyyears.
So everywhere he goes in hishouse, he will hear a soundtrack ofmusic.
And, youknow, what the implications of thatare.
When it was theimplications.
So initially he thought he was going slightlymad.
And he thought thatactually,well, first of all he thought that his neighbors were playing radiovery, veryloudly.
And then he thought he was going slightlycrazy.
But actually it turned out that one of the reasons why he was experiencing musical hallucinations was because he was losing his hearinganyway.
Andso, youknow, it goes back to the fact that when the brain is starved ofinputs, it creates its own experiences because it's eager to experiencelife.
But also the counter-sight of that is that this association between hearing loss and cognitivedecline.
Thatactually, youknow, it's important to look after your hearing because it provides important inputs that maintain the health and the integrity of ourbrains.
So there are lots of these aspects of that you can take from clinical medicine and apply them to what it tells us about ourselves and how our own brainswork.
So how has it changed you meeting all these people and doing all this work because it can't be easy attimes?
It must have had left sort of fingerprints on you in some sort ofway.
Look, I think the problem is that particularly when you're sitting in a busy NHS clinic where you've got a very limited amount of time to seepeople, it is often very much focused on the problem that is sitting in front ofyou.
And byproblem, I mean theissue, the medical issue that is affecting thatindividual.
Whereas writing these books and talking to thesepatients, I think it's given me much broader appreciationof, youknow, what it is that we are actuallydoing.
In theNHS, you kindof,yes, yousee,well, I'm treatingthat, I'm diagnosingthat, I'm maybe curingthat.
Butactually, you see the much wider implications on those individuals when you are addressing theirstories, their experiences in a much broaderway.
You see the impacts when their families and the people aroundthem.
And that stuff stays withyou.
Andundoubtedly. How do you take care of yourself to make sure that that stuffdoesn't?
The other sponsor is not verywell.
Really?No, Imean, youknow,look, I try and have downtime and I try and get away and get out ofLondon.
But Ithink, youknow, this is something that everybody in the NHS is currentlyfacing.
Everybody is feelingvery, very burntout.
Do you sleepwell?Sometimes.
We have a closing tradition where the last guest leaves a question for the next guest not knowing who they're leaving itfor.
Okay. And the question left for youis, what is the most difficult decision you ever had to make and how did it benefityou?
Oh,God. I think there's lots of ways to answer thatquestion, isn'tit?
What came tomind? I thinkthe, I can thinkof, youknow, clinical situations where I've had to make very difficult decisions about whether or not to treat somebody or not to treat somebody to whether or not to whether or not to give up on somebody or whether or not to continueworking, youknow, the sort of situation like cardiac arrestswitch, all doctors have toface.
Personaldecisions, youknow, I think certainly making the decision to study medicine was an important fork in the road for mebecause, youknow, medicine brings with it lots of amazing things and amazing experiences and we see through windows on life that very few other people get tosee.
And it comes withit, with it quite a lot of responsibilities and implications in terms of the future direction of yourlife.
So I think there are different ways to answerthat.
Thankyou,guy. You write such interesting books and such interesting ways and they're all absolutelyfascinating.
So usually I'd recommend one ofthem, but I have to highly recommend all ofthem.
I'm going to link all of them below in thedescription.
Seven deadlysins, the biology of beinghuman.
I've got the man who tasted words inside the strange and startling world of our senses and the secret world ofsleep.
All of them will be linked below the seven deadly sins book is not out until November21st, Ibelieve.
So you can probably pre-order thatnow.
You can keep in mind gettingthat.
So check out the descriptionbelow.
All of the books are linkedthere.
And thank you so much such a fascinatingconversation.
