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The future of sleep

2025/5/23
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The Future of Everything

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Russ Altman: 睡眠对认知、记忆和新陈代谢都有影响,但最明显的影响是感到疲倦。如果睡眠不足,认知能力、记忆力和新陈代谢都会受到影响,但这些影响都不如疲倦感来得直接和强烈。睡眠不足会让人感到疲惫,这才是最主要的问题。 Jamie Zeitzer: 睡眠的主要作用是为清醒状态做准备。睡眠期间可以优化任何在清醒时无法进行的信息收集。睡眠不仅仅是为了休息,更重要的是为清醒时的活动做好准备。在睡眠期间,身体和大脑会进行各种优化和修复工作,以便在清醒时能够更好地运作。因此,睡眠是清醒状态的基础,没有良好的睡眠,清醒时的效率和表现都会受到影响。

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This is Stanford Engineering's The Future of Everything, and I'm your host, Russ Altman. I thought it would be good to revisit the original intent of this show. In 2017, when we started, we wanted to create a forum to dive into and discuss the motivations and the research that my colleagues do across the campus in science, technology, engineering, medicine, and other topics.

Stanford University and all universities, for the most part, have a long history of doing important work that impacts the world. And it's a joy to share with you how this work is motivated by humans who are working hard to create a better future for everybody. In that spirit, I hope you will walk away from every episode with a deeper understanding of the work that's in progress here and that you'll share it with your friends, family, neighbors, co-workers as well.

Is your cognition as good if you don't get enough sleep? No. Is your memory as good? No. Is your metabolism as good? No. But all those pale in comparison to the fact that you feel tired. Right. And so, you know, what is sleep doing? Well, it's doing a lot of things. You know, I think that there's no singular thing that it does. It basically, it prepares us for being awake. This is Stanford Engineering's The Future of Everything, and I'm your host, Russ Altman. If you're enjoying the show or if it's helped you in any way, please consider sharing it with friends, families, and colleagues.

Personal recommendations are a great way to spread news about the podcast and help us grow. Today, Jamie Zeitzer will tell us about sleep. He'll tell us that one of the big problems if you're having trouble with your sleep is worrying about it. He has some hints about how to loosen up, worry less, and sleep more. It's the future of sleep.

Before we get started, a reminder to please tell your friends, family, colleagues, acquaintances, anybody you know and like that they should listen to the Future of Everything podcast. Spreading the word is the way to go.

Well, we all know about sleep. We all know that it's critical. We know that it's annoying not to get enough sleep, and it's great to get a good night's sleep. But the frequency of folks who have trouble with sleeping is remarkable. One of the things that they do is they worry about their sleep. We're going to find out that worrying about your sleep is a great way to make sure that you don't get great sleep. But what about medications? What about wearables? My watch can tell me how well I slept last night, but guess what? I kind of already know.

Well, Jamie Zeitzer is a professor of psychiatry and behavioral sciences at Stanford University. He's an expert at circadian rhythms, bad sleep, good sleep, and how to optimize sleep. He's going to tell us that wearables don't work, there are some medications that sound pretty promising, and don't worry about it as much as you are because that's contributing to the problem. Jamie, what made you decide to devote your professional life to the study of sleep?

Probably the old adage of, you know, physician helped by self.

Never been a good sleeper, always had problems. Actually came in through a back door. I was trained in circadian rhythms, but found that sleep paid the bills better. Okay. Well, that leads right to what I wanted to ask you about, which is two things. Why do we sleep and how is it related to our circadian rhythms? And maybe you should define for those who haven't thought about circadian rhythms very much. What are they and how do they relate to sleep?

Sure. So circadian clocks, something I didn't hear about until graduate school. So if people haven't heard about it, that's OK, though it is definitely more out there right now. These are intrinsic 24 hour rhythms. I find them particularly appealing. They are endogenous to an organism and you find them in every single organism that has ever been studied on the planet Earth.

So there's obviously something incredibly important about them if throughout the evolutionary tree you see them. And these are basically the key to these rhythms is that they allow you to anticipate changes in the future, as opposed to responding to the environment. You can anticipate them.

And so one of the obvious anticipations that we have as humans is sleep. And so it's very much intimately involved in the timing of sleep, when we sleep and how we sleep. So it sounds like from what you're saying, I'm kind of it's kind of implying to me that circadian rhythms might have lots of other uses to the organism other than telling us when to go to sleep and when to wake up.

Absolutely. They're basically involved in pretty much any physiologic process. I mean, the vast majority of them have a circadian component. The real question is, what is the magnitude of that component? And in fact, when people show like, oh, there's no circadian component, I'm like, wow, that's really important because it means that you have to be up all the time. There's no anticipation for it. And so everything, if you look at immune system, if you look at breathing, heart,

Every aspect of your physiology, there's a circadian component. Okay, great. Okay, so and now let's go to sleep. And I kind of buried it, but like do we understand why we sleep and why it's critical? No.

Okay. Thanks very much. That was Jamie's answer. There you go. So, I mean, you know, we have ideas about what happens during sleep. You know, what exactly, why is it important? I mean, by far, if you take a look, by far the biggest effect size about losing sleep is you feel tired.

And it's not I mean, it's more than tenfold bigger than any other like cognitive effect. Like basically, is your cognition is good if you don't get enough sleep? No. Is your memory is good? No. Is your metabolism is good? No. But all those pale in comparison to the fact that you feel tired. Right. And so, you know, what is sleep doing? Well, it's doing a lot of things. You know, I think that there's no singular thing that it does. It basically it prepares us for being awake.

And anything that can be optimized during sleep while we're not awake and gathering information, that's kind of what happens there. So you said earlier that part of the reason you entered the field is you have problematic sleep. And I want to get into that. Well, perhaps not your personal sleep situation, but the issue. But I will also just disclose that I feel very lucky to be, I don't know what the word would be, but gifted would be the only thing I can think of. And it's been an incredible asset to my life.

When I get nervous about things, I actually go to sleep instead of staying awake. And it was extremely adaptive as a student and whatnot. Okay, enough of the biography. I know you've studied a lot about light. And there's a sense that we all have that the circadian rhythm, in some sense, is kind of synchronized with the sun. And so tell me about the role of light and particularly in sleep. Sure. So circadian.

Where the circuiting clock in humans on average is a little longer than 24 hours, around 24.2 hours. So it has to synchronize to a 24 hour day. How does it do that? Mainly through light. And so basically your light exposure is dictating where the circuiting clock is placed. The most obvious place that you experience this is when you travel across time zones. You go into a new time zone. How do you adapt your internal clock to the external time that you're living on? That's through light exposure.

So the light exposure is basically dictating where the circadian clock is positioned and therefore where when you're sleeping, when you feel tired, when you feel alert. And is it certain? Is it sunlight? Is that what we need? Are there certain waves of light? I know you've looked at flashing lights. This is all very interesting.

Yeah. So, you know, basically anything you can see can impact the clock. And it's just a question of magnitude. If you are completely optimized, so you've been in a dark environment for a long time, even fairly dim light, you know, just like a few candles worth of light can impact the clock. But in general, in most adult humans, you're talking about room light being effective and outdoor light being about twice as effective.

Even though outdoor light is more than tenfold brighter, there's a compression of this information. But that being said, room light is about half as important as outdoor light. So even what you're getting in a standard office environment, home environment can be very impactful. And

And does that have any implication for like optimal? So I think of room light as a little bit more orange, a little bit on the red side of the spectrum. I think of sunlight outside as a little bit more blue. Sure. Does that imply if we're spending time, you know, a lot of us are in offices that we don't get to go be outside all day. Does that make implications for what kind of lighting we should or should not be using in our internal environments? Yeah. So the,

The circadian clock is definitely optimally sensitive to the shorter wavelengths, blue light. And that's because basically how light information goes from the outside into the circadian clock is

is a combination of your rods and cones, which again, you see things with, which are more optimized in, in total to green light. But then it also uses this substance called melanopsin, which is a option. It's basically, it's a protein in the eye that can also respond to light and that's blue sensitive. So this is why when you hear a lot about blue light,

that's the kind of the concern now again any light can have an impact but blue light photon for photon is more impactful so when you're inside the real thing about being inside and again after the pandemic so many people working from home um the real thing is that you need to create a contrast right so so basically the brain is and circadian clock is really good at

adapting to your light level so even if you were say living in a cave all day if you had five minutes of light that would be totally fine huh right but you need a contrast you need dark and you need light and so if you're basically inside all day in an office and then you're it's a home office and you're into the same lighting throughout the evening there's no contrast it didn't know that that was day and that this is night ah

And so the really the thing that people have to pay attention to in terms of working from home, things like that, is that.

They have to create this contrast. And that contrast might be have better lighting in your office. So basically brighter lighting. I mean, we found that even if you just increase the brightness of your lighting during the day in our home office, that's sufficient. Or go outside, which is good for a number of reasons. Yes. But, you know, go outside for a half hour in the afternoon, like three o'clock in the afternoon. Ideal time to go outside.

You get the light there. And the other thing that that does is that it also minimizes the impact of light in the evening. So the light, how the how the clock responds to light, as well as many other kind of impacts in the brain, it's it's a relative thing. So it's not just looking at how bright it is. It's how bright it is compared to what you were getting before. So if you're inside all day, there's no contrast.

If you go outside for a half hour in the middle of the day, you get, well, nice California weather. We're getting 80,000 lux outside. You come back inside and you get 50 lux. All of a sudden that 50 lux isn't so bright. But if you were getting 50 lux all day and then you're getting 50 lux in the evening, you're

that appears brighter to the system. Okay, so I do want to go to the issue of people who are having problems with sleep. And I think it's going to be related to a lot of these things. We're all getting advice about if you're looking at your phone at midnight, you should be looking at your phone with an orange light and not with a blue light. I don't even know if you want to comment on that at this point. Oh, sure. No, absolutely. A lot of things do, but this particularly drives me nuts. Okay.

So, if you are, again, inside all day long, don't get any bright light, can that light from your phone impact your brain? Sure. Absolutely. I mean, physiologically speaking, you keep someone in dim light all day and you give them a phone at night, it will impact it. The vast majority of people, though, don't do that, right? They're getting any degree of light.

That would really minimize that light. So the problem is that when you say, oh, I've got the orange filter on my phone. Now I can do whatever I want. No, it's like you're doing things like you're checking your email, which is stressing you out, or you're on an app that has been optimized by psychologists to keep you on the app. You know, I've got this great clip that I love playing for classes here, which is of Reed Hastings, who's the CEO of Netflix. And during a corporate earnings call, and this was several years ago,

He said, our biggest competitor is sleep. Oh my goodness. And he wasn't kidding. It's because you've got the next episode button and you just keep next episode, next episode, next episode. And so you don't, you know, you don't pay attention to sleep. So,

Blue light, light filters on phone. Do they work? Yes. If you're inside all day, they're nice. But by far, the much bigger thing is the content, what you're experiencing, how it's impacting you. If you're checking something out, you know, and you're stressing out like, oh, my God, everyone else is having so much fun. I'm not having fun. Yeah, that's going to keep you awake. Right. Or, oh, look at all this work I have to do.

Going to keep you awake. Oh, politics. Wow. Yeah, that's definitely going to keep you awake. Right. So perhaps the blue orange thing is in the noise of all the other stuff that's happening. When you look at the effect size, it's not even close. I mean, the only good thing that it really does is that it provides kind of like an inverse alarm clock.

it reminds you it's time to go to bed. Like when your screen automatically changes color, you're like, oh yeah, it's 11 o'clock at night. It's time for me to go to bed. I lost track of time. So in that sense, it can be a helpful psychological cue. But in terms of its actual effects in the brain, it's really doing quite little.

Okay. So let's go to problems with sleeping. Uh, it is so common. Like, uh, it's the number I'm aware of it. Cause as I said, I don't have problems. And so I'm maybe a sensitive to hearing how many people are struggling with it. Uh, it's a topic of conversation. Um, what can you say about it? Like, what are the sources of this? What,

What I am impressed by is when you ask, I'm a doctor, I can ask somebody, how's your sleep? I do not have to explain what it means. They know if it's good or bad or middling. And so tell me about sleep problems and how we should think about them.

Yeah. So it's good that as an MD, you actually ask people that question because most MDs do not want to ask that question because then they'll get an answer and they don't know what to do. Right. Right. So I've got to document that. So. And doc, can I have a pill, please? Exactly. Because that's what people want. I mean, they just want they want an on off switch. We don't have that. There's so there's been a lot of concern about sleep. There's been a lot of concern.

There have been many things published in the lay press, books telling us how terrible it is to lose sleep. I don't happen to agree. Now, I'm not saying that the data are wrong, but I don't happen to agree that scaring people into getting more sleep is actually an effective way of getting them more sleep. What it does, it makes them more anxious about their sleep.

And the only thing worse about not getting enough sleep is not getting enough sleep and being anxious about it. Yeah, yeah. That's worse. I mean, the stress that you're experiencing, that's doing far more damage. Honestly, losing a night of sleep or not getting great sleep, it's more like a lottery ticket. Very long odds. And you're talking about like you telling someone who's 25 years old, you know what, you should get better sleep because...

In 30 years, if you don't get good sleep now, you're going to have like a 3% increased risk of getting diabetes. I mean, it's stupid. I mean, that's not going to actually change people's behaviors. So there's a lot of anxiety, and that's bad.

That's causing problems. We can talk about wearables. They don't work. Oh, wow. Okay. So you went right to the wearables and like, you know, my watch every morning is telling me exactly how much time I spent in each of these phases that I don't really understand, but it's very impressive.

Yes, it's nice. But if you're in you, it's probably actually reasonably accurate. In bad sleepers, it is completely inaccurate. And there are a number of reasons for that. But the biggest problem is that even if it were 100% accurate in everybody,

It's decontextualized information. It makes people anxious about their sleep, especially if, look, if they're getting good sleep, fine, great. But if you're getting bad sleep and it's actually saying, well, you didn't sleep well last night. You know, you didn't get a lot of deep sleep. You got too much N1 sleep.

What am I going to do about that? Like now you just make me anxious. Like before I just woke up and I was tired. Now I'm waking up and now I'm anxious. So it's not particularly helpful. And that's something that I hope in the future, basically, this is one of the things that I think

That we need to get to is not only making that data accurate and people who are bad sleepers, but also then contextualizing it in terms of what you can do. Yeah. Actionability is always kind of on. That's what that's what the physicians would want. That's why they would they would ask more if they had a toolkit to actually be helpful.

Exactly. Look, there are standard kind of interventions that work quite well. CBTI, cognitive behavioral therapy for insomnia, works really well if people are willing to do it. It's not talk therapy. It's not, you know, like how your mom screwed up your sleep and your entire life kind of thing. This is more on like, okay, okay.

You know, here are some tools that you can use to get sleep better. And the amazing thing about it is when you look at the objective measures of sleep and someone who's been successfully treated, like they had bad insomnia and now they say they're fine. Their objective measures of sleep really don't change that much. What changes is their perception. They basically, you teach them not to care about their sleep so much. And so if it takes you, for example, if it takes you a half hour to fall asleep, that would be considered a long time.

But if it doesn't bother you, that's not insomnia. Clinical definition of insomnia and all of the international definitions, no numbers, right? So it's not about how long it takes you to sleep. If it takes you 10 minutes to fall asleep, which is totally normal, but you're anxious about that, that's insomnia. Okay. So there's a functional element to these diagnoses, which actually sounds like the right answer.

Yeah. I mean, so it's basically saying like, if it doesn't bother you, okay. You know, and, and really there's, there's been a move, you know, people have for a long time, really kind of dichotomized sleep. You have good sleep or bad sleep, you know? Now we understand that there's, there are people with good sleep and there, and there are people with pathologically bad sleep, but it's a bell curve and there are different components. Duration is just one of them.

You know how regularly you go to sleep like if you you might have like when we study college students they're wonderful to study because I I often went when I when I lecture to them I'll thank them because I say because you do things to your sleep that we study that ethically we're not allowed to ask The ethics board would never let us do what you do to yourself.

No, in a million years. It's like, so what I want you to do is sleep three hours tonight, but go to sleep at 2 a.m. Then tomorrow night, I want you to not sleep at all. And then the next night, I want you to go to sleep five hours earlier, but sleep 10 hours. It's like, you can't do that. Like, there's all sorts of data saying how bad that is for you. But people do this. So, you know, and they very rarely have, you know, insomnia. I mean, many, you know, there are many college students who do, but they're usually so sleep deprived. Right.

There's no insomnia. I mean, we, in fact, have studied in the past, we did a modeling study looking at the impact of caffeine and basically found that for most college students, caffeine has no impact. Like they're having like 600 milligrams of caffeine right before they go to bed and fall asleep instantly because they are so sleep deprived. Yes. My daughter is a resident. She's a medical resident.

And she's had sleep problems in the past per her own report. But I asked her about her sleep during her residency and she said, that has gone away, dad. If I see a bed, I'm asleep. See, there you go. This is where gurneys all of a sudden look like comfortable, you know, sleeping positions. This is the future of everything with Russ Altman. More with Jamie Zeitzer next.

Welcome back to the Future of Everything. I'm Russ Altman and I'm speaking with Jamie Zeitzer. In the last segment, we talked about some of the basics of circadian rhythm, sleep problems, and worry. In this segment, we're going to touch upon medications and we're going to talk about some easy do's and don'ts that can help you improve your sleep if you're not happy with it.

We were just talking about these college students that you talk to and the fact that you can kind of, my words, not yours, you could hardly pay them to have more bizarre sleep habits. So what kind of things do we learn from those students and teenagers and people who are at the extremes of like testing their sleep ability? Yeah, so we use it to our advantage. Basically, what we do is we, when they have these kind of weird schedules,

we're able to then look and see what is the contribution of circadian rhythms and what is the contribution of sleep. So in normal humans that are regular sleepers at all, when your circadian clock is timed is almost always at the same time relative to sleep. Like it's always signaling for sleep when you're asleep. In college students, sometimes it's signaling for sleep when they're awake, sometimes it's signaling wake when they're asleep. So basically it's

It's called basically a desynchronization of these two systems. So it basically gives us an opportunity to study what the contribution of this. So, for example, we're right now we're just finishing up a study where we're looking at how sleep and circadian rhythms in the menstrual cycle impact injury risk in women.

college aged women. And so basically these have been studied independently, but these are not independent factors. So the question is, well, can we use this and kind of tease it apart? So we're using it basically as kind of a scientific tool. Now, of course it would be great if they slept better, but you know, students are busy. They've got fun lives as interesting things.

And so we're letting them do that and then trying to figure out like how to adapt afterwards. Really interesting. So that made me think that is it something about college or is it that age group? So if I look across the world at people in that age range, let's say 18 to 22, are they kind of always a little bit wacky with their sleep or is this a phenomenon about the college?

I think it's a combination. I think at that age, basically, you have the independence to do this kind of stuff. And you also have the recovery. You know, as I as I tell my younger students, like, it's not that I can't do it anymore. It's that I can't do it anymore. Like every night. Right. You know, I can't stay up until three o'clock every single night. I do it every once in a while. And then it kills me for a week.

But they can do it and then just like roll out of bed next day. Fine. So their recovery is is remarkable. So basically they can do it and it's fun. And, you know, I think it's a time of life, especially in college. But even if you're not in college, even if you're working with, there's a lot going on. Yeah. You know, you're exploring a lot who you are, various kinds of interests, things like that. So, yeah.

I know it's unique to the college, but I do think that it definitely accentuates this. It gives you kind of a protected realm to kind of do this and, you know, and occasionally study things like that. So what about folks who are, you know, they grow older and they're involved in shift work? They have shifts, you know, nurses. We all know the kinds of folks who do that. That's a big deal for them, I'm guessing. And how do they manage it? And what do you learn from looking at their, do they just switch their circadian clocks or is it more complicated than that?

Yeah, so they try to, but they can't. So basically what happens is we have the technology to flip people's clocks. We can make day people night, night people day. Not a problem.

But it takes time. Let's put a pin in that because we want to hear about that for sure. Yeah, so but it takes time. You know, it'll take like a week. So if you're on permanent night shift, you can totally do that. But the problem is that people who are on permanent night shift, then on their days off, are day shift. They want to be awake during the day, see family and friends. So we don't have the ability to flip people back and forth, let alone what is more common in shift work, where it's people kind of flipping back and forth on multiple different days.

So they end up basically getting meh sleep all the time and then being tired a lot. So we try to work with them, things like taking naps, prophylactic naps, so basically nap before you go on a night shift. I have to say a lot of the older nurses that we've worked with, you know, they enjoy that.

you know, my wife, she's a hospitalist, right, pediatric hospitalist. And so I think it's basically to directly insult my profession, because she's worked 26 hour shifts for the past 20 years. And, but she likes it, because it gives her a flexibility in terms of her schedule and being able to, you know, she was able to be with the kids when they were younger. And now when they're a little older, you know, to be able to see them after school. So

It gives them certain flexibility. Other people are on shifts because they have to. It's economic necessity. They don't want to be on shifts, but they have to. And it's difficult to do this. It's difficult to sleep during the day. You know, we can do that. We've got medication that we've tested. We've shown that we can take people who are shift workers and –

and basically have them in the wild. So they're doing what they do. They normally sleep around four hours. And we can give them medication that basically suppresses a wake-promoting signal, which is hypocretin, and basically suppresses this signal. And hypocretin is something that if you don't have it, you have narcolepsy. But you can suppress the signal. It doesn't do much else in humans except this wake-promoting signal. So when you suppress that, they go from getting four hours of sleep to getting six to seven hours of sleep.

So you can totally get that if you're willing to take a medication during the day. If you're not willing to take a medication, it's really hard to get more than four hours during the day. Okay. So you said the word medication. I know everybody is interested in this. So talk to us. We know about benzodiazepines like Valium. So tell us what the status is. And does any of this work? Does any of it look promising to you? Where are we?

So benzodiazepines work great if you don't want to be awake. They don't recapitulate normal sleep. But for most people, for short term, your dog just died, you're totally stressed, you can't sleep. A benzodiazepine does exactly what you want, which is it puts you into a state of not being awake. Right? So...

That's fine. I totally see how that works. And I support that. And I think it's a great kind of medication to basically anesthetize people, put them into a state of not being awake. So I'm not staring at a ceiling for eight hours. Right. And anxious and stressed and feeling miserable. At least you get some degree of sleep. Again, it's not perfect. It definitely is not the same as normal sleep.

So, there are many other drugs that have been used for years for sleep. None of them really recapitulate normal sleep very well. Using medication for chronic sleep is not a great solution. People use it all the time, though. The most common things that people use are antihistamines. Yep. And antihistamines work quite well. Benadryl for the kids on the flight to the East Coast. Yep.

But you got to watch out because if they have the paradoxical hyperactivity. Bad news. Yeah. So test it out before you go on the plane. But so, I mean, you know, antihistamines work great in the sense that, you know, histamine is a wake-promoting peptide.

you're going to suppress that wake-promoting peptide, which enables normal sleep. And that's fantastic. That's what you want. Then you get normal sleep. However, antihistamines are not just antihistaminergic, they're also anticholinergic, so you get a lot of cholinergic side effects. They also obviously work on all histamine receptors, you know, including H1, which are on immune cells. So it's, you know, you take the same drug if you've got hay fever as you do if you want to go to sleep. So

It's not ideal. So there are people working on drugs that are going after the H3 receptor, which are autoreceptors on the histaminergic neurons in the brain. They would be more specific? It would be specific just to the brain, would get out the immune effects. They already have ones that are out there for alerting, but it's a little trickier to develop an agonist for these receptors because if you basically activate these receptors, you're reducing histamine.

because they're auto receptors. And so basically, so these are great, but they're not out there yet. So hopefully, we're hoping that this will go out there. There are new drugs that block the hypocretin receptors that we talked about that basically blocks his weight promoting system. They work okay for some insomnia, especially if you're trying to go to sleep at the wrong time.

It's a weird thing is your strongest circadian signal for wake occurs right before you normally go to sleep. Oh. So if you go to sleep at 11, it's really hard to go to sleep at 10 or 9 or 8 because the circadian signal is basically keeping you awake, trying to sustain your wakefulness, waking day to 16 hours. It's why if you go from California to New York, you normally go to sleep at 11. You try to go to sleep at 11. You can't fall asleep. Why? Well, because it's 8 o'clock in your brain when you first get there and your circadian system is telling you to be awake.

So the circadian system at bedtime is more like a cliff. It's not a slow reduction. Cliff is the right metaphor. Yeah, it really, you have this weird window of opportunity for sleep where basically when the circadian system turns off this strong alertness signal, which really is a very robust signal and does drop off, as you say, like a cliff, that's your opening of this window to go to sleep.

If you spend too long awake after that, the brain's like, oh, Russ, you're trying to stay awake. Let me help you out. Let me over ramp all of these systems that shouldn't be up right now. So we're going to increase norepinephrine. We're going to increase dopamine, serotonin. Let me help you out. And so then you become agitatedly awake and then it's hard to fall asleep. So it's a window. What about melatonin? So open label studies of melatonin. You give melatonin to someone who knows they're taking it at night.

30 minutes up to 60 minutes of extra sleep. Great. Extra sleep. Extra sleep. Yeah. Yeah. Double blind placebo controlled trial, five minutes of extra sleep. It's a great placebo. So basically, melatonin does not work well at night. It works well during the day, gives you around an extra half hour during the daytime. When you say it works well the day, it helps you like with a nap?

Yeah, yeah. Helps you with a nap or if you're traveling and you're traveling and you want to sleep, but in your body, it's the daytime, then it can work. Okay. If you're doing a shift work, and again, you're trying to sleep during your biological daytime, it can work. But at night, it really has a very small effect. The other problem with melatonin, of course, is that

the dosing. So if you want to get normal physiologic levels, you're looking at 300, maybe 500 micrograms, which is 0.3 to 0.5 milligrams. Of course, you go into the store, and it's really hard to find something that low. It's usually 1, 3, or even 10 milligrams, which are super pharmacologic, thousands of times higher than normal levels. And

The best part is if you take it at night, not only is it not really going to help your sleep at night, but the levels are going to be really high when you wake up in the morning when it's actually going to be effective. So it's going to make you tired in the morning. So now when I tell people not to take melatonin, if they're using it, no, it's a great placebo. If you basically say, oh, I take this pill and then I can sleep, you've overcome the major barrier. And that makes me think about all your comments earlier about worrying and anxiety. And that's what you're treating. Exactly.

Yes. Yes. You're now you have basically you have done something with CBT. I try to train you to do on your own. You have relaxed enough to let sleep happen. Right. Because it's not saying that it's one of the weird things that you can't actually work harder to get better sleep. Right. You know, when I when I talk to athletes, they're always looking to optimize. Because that's what they do. Exactly. And they're really good. They optimize their diet, their exercise, their time management. It's fantastic. You try to optimize their sleep.

And that's awful. I mean, that just does not work. Great. Okay. So in the last minute or so, I love to, I'm sure you can do this. Tell us, and you've told us already, but it's fine to repeat yourself. Somebody who's worried about their sleep. What are some of the do's and don'ts that you would tell your friends, your patients, anybody about how to kind of deal with this issue?

So easier said than done. Don't worry. Worry a little, but not too much. Okay. Again, how, how, how do you get to that sweet spot? I don't know that that's really hard. And that's actually my, my, my clinician colleagues who do CBTI that they're wonderful at getting you to that spot where, again, you're just concerned enough. I mean, to me, some of it is, well, a big part of it is regularity, regularity, not only in the timing of when you try to initiate sleep. Again, that is great for the circadian clock. Um,

but also regularity in terms of Pavlovian conditioning. You're basically saying, here's what happens is I brush my teeth. I wash my face. I get into bed. I listened to my podcast.

Future of Everything is really good. You should listen to it at some point. Very soporific. Let's skip over that. There you go. And then I go to sleep. You know, you set up this routine and it's really helpful. It really helps the brain kind of anticipate like this is what's going to happen. Now, me, I like doing puzzles. I'll do like crossword puzzles and things like that because it's engaging enough that it doesn't make me awake, but it allows me to be distracted and actually fall asleep.

Other people, podcasts, some people do yoga, some people listen to music. It's something which is not going to stress you out. Like, I love people thinking like, I'm basically, I'm alpha, I'm up all day, I'm stressed all day, and then I'm going to turn it off and go to sleep. That's not going to work. You got to slow that roll during the day because it's really hard to come down. So,

It's finding whatever is personal to you. There's no one thing that does it. If you like doing breathing exercises, fantastic. That'll work. But so will all of these other things. It's basically whatever calms you down. Alcohol, caffeine? So a lot of my colleagues are very much against alcohol. To me, it's a balance. Again, it's not good to have a drink in order to go to sleep.

But if there are times when like you're flying and you're anxious and you're taking the overnight flight and having that, you know, that half a glass of wine is going to help cut the edge and like make you not anxious, but then enable you to get sleep. Your sleep's not going to be as good as it would have been if you could have just fallen asleep naturally, but it's better than not sleeping at all. Caffeine is something that I always caution people to worry about because it's really weird. It's something that's strange about caffeine because when you look at absolutely healthy people,

The half-life range is 2 to 12 hours, which means that some people have a cup of coffee in the morning, and by lunchtime, it's all gone. Other people have that same cup of coffee in the morning, and at night, you have half a cup running around your brain. So it's really being aware, and this actually comes in as people get older. You become your thalamus, your gateway to the brain becomes conscious.

less able to cut out these signals, right? So it's much easier as you get older, you know, the noise wakes you up now. It used to not. Caffeine will wake you up. It used to not. All of these other things, just being aware of that. So again, caffeine, again, there's nothing wrong with having caffeine. As I told you in college students, they have all this caffeine doesn't impact them. When we look at soldiers in the

silly amounts of caffeine and they can, you know, and it's totally messing up their sleep. So it's, it's really just being aware, like, could that be impacting your sleep? Even if it's in the morning, you know, people have shown you give 300 milligrams of caffeine in the morning. And in some people it impacts their sleep at night. So it has the capacity to do so. It's just really being aware of whether you, you know, if you're a fast metabolizer or not. Um, and,

It's also where actually women on oral contraceptives, actually it changes the half-life as well. It increases the half-life. So you got to be worried about that. That's really helpful. And I do know, again, as a physician, that people are usually very aware of their caffeine sensitivity. It's something that they've all assayed. And so you ask somebody, when's the last time you can have a cup of coffee? And they are calibrated to within half an hour about when that last caffeine can happen.

Thanks to Jamie Zeitzer. That was the future of sleep. Thank you for tuning into this episode. Don't forget, we have zillions of old episodes in our back catalogs, and you can spend hours and hours listening to them and learning about a wide variety of topics. If you're enjoying the show, please remember to share with your friends, family, colleagues, acquaintances, anybody who you like. Tell them because personal recommendations are a great way to spread news about the show and help us grow. You can also find us on Facebook, Twitter, or Instagram.

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