Plain English with Derek Thompson - The Most Important Thing Most Americans Misunderstand About Insomnia

Episode Date: April 25, 2023

I am fascinated by sleep and also—perhaps, relatedly—not very good at it. Like tens of millions of Americans, I've had trouble falling asleep and staying asleep for most of my life. I also know that sleep is the glue that holds together health—a fact that sometimes haunts me as I toss and turn at night. Behind the fitness and health fads, what's the truth about insomnia? How dangerous is it? When do we know when we have a problem? How is it different from sleep deprivation? What have we learned about sleep in the last few decades that's most important for average people to remember? Dr. Jade Wu, a behavioral sleep medicine specialist and researcher at Duke University School of Medicine and the author of 'Hello Sleep: The Science and Art of Overcoming Insomnia Without Medications,' explains how the modern panic about sleep and insomnia misunderstands some fundamental facts. If you have questions, observations, or ideas for future episodes, email us at [e-mail]. You can find us on TikTok at www.tiktok.com/@plainenglish_ Host: Derek Thompson Guest: Dr. Jade Wu Producer: Devon Manze Learn more about your ad choices. Visit podcastchoices.com/adchoices

Rough year for your favorite NFL team. Join me, Danny Hyfitz, along with Danny Kelly, Ben Sulek, and Craig Krollabak on the Ringer NFL Draft show where we talk about all things NFL draft. And more importantly, how to fix your mediocre team. Check out the Ringer NFL Draft show every Tuesday and Thursday. Today's episode is about sleep. Some of the episodes we do on this show come from my curiosity about the world. And some of them come from my curiosity about my own life.

This episode belongs firmly in both categories. This is research and this is me search. I am fascinated by sleep and also, perhaps relatedly, not very good at it. I've had various forms of insomnia for most of my life. In college and in my 20s, I struggled to fall asleep. In my 30s, the trouble is now mostly staying asleep. I can't count the number of times. I've woken up at 3 a.m. in the morning and suddenly alert wide awake.

And a few years ago, I was researching my own nocturnal issues. when I discovered the work of a historian named Roger Eckertch. In the 1980s, Eckertz was doing research for a book about how older societies think about the nighttime, and he stumbled on references to two mysterious terms, first sleep and second sleep. He found these terms in a crime report from the 1600s. He had never seen those phrases before,

and when he broadened his search, He found mentions of first sleep or second sleep in Italy, in France, across Africa, in the Middle East, South Asia, Latin America. In Germany, he found evidence of middle of the night insomnia in no less than the journals of Martin Luther. Yes, the father of the Protestant Reformation. In the 1540s, Luther wrote this about his midnight strategies to ward off the devil. quote, every night when I wake up, I instantly chase him away with a fart. End quote. What it all meant is that segmented sleep is an old habit, or as Eckers calls it,

bifasic sleep, meaning sleep in two phases. Many and perhaps most people who have ever lived broke up their sleep in two parts until the Industrial Revolution. Beginning in the 1700s, Eckridge thinks, the accoutrements of modernity, that is, light, caffeine, clocks, and above all, modern work schedules, took the history of biphasic sleep, segmented sleep, and mushed it into one contiguous eight-hour rest. How did it do this? Well, electricity and other forms of artificial light delayed bedtimes. People could stay up later, eating, drinking, reading. new factory schedules required early wakening.

Caffeine made those early wakeups a little easier to bear. And so today, while you and I live in a world where one-shot sleep is basically the norm, it's two-part sleep that might be how the human body wants to rest. In fact, in the 1990s, there was a study done by the National Institute of Mental Health that deprived a cohort of male subjects electric lights at night. They took away electricity from these guys. after a few weeks, these dudes' sleep became segmented. They reverted back to our old pre-industrial biphasic sleep habit.

So maybe my middle of the night insomnia, and perhaps your middle of the night insomnia, is just one of those things where we can just blame capitalism. Maybe industrial capitalism took our perfect two-part beauty rest and just smashed it into one go. Maybe. But the deeper you dig into questions about sleeping habits, the more you realize just how diverse sleep is, not just among humans, but also among animals. Studies of hunter-gatherers in Tanzania, Madagascar, and Bolivia have found that tribes there actually mostly enjoy one long sleep. They sleep just like today's post-industrial workers.

And as my colleague at the Atlantic, Katie Wu, pointed out recently, there is no singular animal recipe for sleep either. Every species figures out its own thing. Cows chew while they sleep. Frigot birds fly while they sleep, seems dangerous. Dolphins shut down half their brain at a time to maintain constant alertness. Elephant seals. Average just two hours of sleep a day. Two hours of sleep broken into about 25-minute naps, which is, according to Wu, the lowest daily sleep total ever recorded definitively for mammal. By the way, there's some evidence that suggests that elephants, too, only need two hours to do their thing, which is sort of a weird coincidence because they have no relation to elephant seals. So what is the upshot of this brief and scattered history of sleep within the animal kingdom? I think it's something like this. Different bodies seem to want to sleep in different ways. So you have to find what works for you and do your best to keep that thing going. Today's guest knows much more about sleep and sleeping well than I ever will.

She is Dr. Jade Wu, a behavioral sleep medicine specialist and researcher at the Duke University School of Medicine. She is also the author of Hello Sleep, the science and art of overcoming insomnia without medications. And why I really wanted to bring Dr. Wu on the show was to answer what for me has become a kind of existential question about sleep. in a recent episode on health trends and health behaviors, we talked about how sleep in some ways might be

the most important habit you can develop. It is the glue that keeps our bodies together. And yet when I wake up in the middle of the night, when we wake up in the middle of the night or have trouble falling asleep, sometimes we start obsessing over the fact that if we don't fall asleep, we're going to lose our glue.

Our life is going to fall apart. How do we balance these two important facts? that sleep is central to our health, and also that if we take it too seriously, we can't fall asleep. I'm Derek Thompson. This is plain English. Dr. Jade Wu, welcome to the podcast.

Thanks so much for having me. First off, tell me who you are, what you do, and how as both a researcher and a clinician, you came to sleep as your specialty. Okay, so I'm Dr. Jade Wu, and I'm a behavioral sleep medicine specialist. So that means I help people to overcome their sleep problems, to improve the quality of their sleep without using medications.

And so I actually came to sleep because of a personal love for sleep. So I started college as a double major math econ, but then there was a prerequisite for an econ class that started at 8 a.m. And I am not a morning person, never have been, especially in college. And I was like, no, no, no, no. I need to get enough sleep. So then what other major can I do that allows me to get up at like eight and go to class at 9.30? And turns out that was Psychology 101.

And it just so happens that the professor teaching that class was a sleep researcher, and I just fell in love from there. My dad's favorite comedian was Lewis Black. And Lewis Black had a line about literally, I think it was economics classes starting at 8 a.m. in the morning on a Friday. And his joke was, are they trying to keep this shit a secret? because that is the only reason why they would possibly start this class at this time on this day.

It's a conspiracy. It is a conspiracy. All of economics is basically conspiracy. I do want to get into the nitty-gritty on the science of sleep and wakefulness, but before we get into the science, there's a big picture question that I want to clear up. I think there's a very fascinating tension,

almost a paradox in America today, at the heart of how we talk about sleep in this country. On the one hand, sleep, we are told, is at the heart of everything. It is one of the most important things in the world. It is the best mood stabilizer. It is the best stress reliever. It is the best immune booster. High quality sleep is treated like a miracle drug. And without it, it's like we're screwed. On the other hand, if you take all of that too seriously, the ordinary person may very well develop an anxiety disorder around sleep. that will increase their odds of insomnia.

And many people, I think, feel that tension writ small when they're lying awake in their beds. It is precisely their urgent anxiety to fall asleep that is keeping them awake. So here's the central tension for an insomniac country as I see it. We are told, if you can't sleep, just calm down. But if you don't fall asleep, you're going to die.

So what wisdom can you offer us to help resolve that tension? Well, you've asked the most insightful question because there is such attention, and I see it with my patients all the time. They're coming in saying, I'm afraid that I'm going to die early because I'm not sleeping well. And the fact that I'm worrying about having hypertension or dementia or whatever is the thing that's keeping me up. So that is definitely a common phenomenon. Now, at the heart of this is a common misconception that I think we all have. And that's that sleep deprivation. And insomnia are used interchangeably as they're the same thing. But actually, they're very different things. In fact, in some ways, they're opposite things. So sleep deprivation is when you don't have enough opportunity to sleep. So this is like the college student pulling the all-nighter to study or party. This is like someone who's working three part-time jobs and they do shift work and they just don't have enough time in bed. So that would be sleep deprivation. And also there are some medical conditions like that. sleep apnea where, you know, your own breathing problems are interrupting your sleep throughout the night. That's also sleep deprivation. On the other hand, with insomnia, you have enough opportunity to sleep. In fact, people with insomnia are usually working really hard to, like, perfect their sleep hygiene and sleep environment. And they have all the right setups and all the time in the world. But then something

internal is keeping them up. So these two are very different concepts. And the, you know, easiest way to think about how they're different is if you are sleep deprived, you are going to be really sleepy, like falling sleep standing up, right? And if you're that sleepy, you're not going to have insomnia. You're not going to have trouble falling or staying asleep. So in this way, these are actually opposite things. I don't think anyone has actually explained it to me like that, that sleep deprivation tends to be high sleepiness, but not enough bedtime, and insomnia tends to be low sleepiness and often too much bedtime. Precisely.

It sounds to me like the way we're panicking about sleep in this country is totally wrong. If it is sleep deprivation that has the higher risk of these lifetime negative consequences, like sleep deprivation seems to be the greater health risk, if I'm hearing you right, while insomnia is the more common anxiety. Exactly. And the irony is people who are sleep deprived, either they cannot. change their schedules and sleep more or get more time in bed or they just don't care. They're like 19 and partying, right? And then the people who have insomnia who really need to calm down more about sleep and be less anxious, they're the ones working really hard to perfect their sleep hygiene.

So in a way, the difficulty, the challenge for us, sleep scientists and clinicians is how do we put a public health message out there that doesn't freak people out too much about sleep, but also tells them how important it is, you know, we're trying to really target the right audience with the right message. And it's really hard to do. Are there demographic differences between the group of people who tend to be sleep deprived versus the group of people who tend to be insomniacs? Great question. So younger people are more likely to be sleep deprived, especially teens, people in college, people in their early 20s, either because high schools start at 730 or 30. or 8 a.m. That's way too early for a teenager, right? Well, we'll talk about circadian rhythms

later, but they are hardwired night owls. They are not supposed to be sleeping that early. So teenagers aren't getting enough sleep. And also, people who are sleep deprived or do shift work or somehow just don't have enough opportunity for quality sleep are more likely to be minorities. So black and brown folks in this country are much more likely to do shift work, for example, or not have good sleep environments. For example, you know, poorer neighborhoods have more lighting outside for, you know, crime reduction reasons. But this also means that there's much more light at night, which prevents quality sleep and disrupts

the circadian rhythm. That's just one of many, many examples for why people in poorer neighborhoods just don't have enough opportunity for good quality sleep compared to, you know, richer neighborhoods. Surely some people's insomnia is so bad that they are sleep deprived. And I don't want to communicate the idea or leave listeners with the idea that insomnia is just always fine and merely some anxiety disorder. And you weren't saying that, but I just want to transition to what's the best way to ask this question? Here, maybe this is it. When is insomnia biologically, physically bad for us versus when is it merely?

annoying. When is it merely the source of an anxiety disorder versus something that is actually bad for our bodies and our health? You know, I actually wouldn't draw the line at, you know, mild versus severe insomnia and how little one is actually sleeping. There's no hard cut off for how many hours you're sleeping that makes insomnia, you know, more problematic than less. I would actually identify, you know, how much is it interfering with your functioning? Because not everybody needs the same amount of sleep. You can sleep four hours and have insomnia. You can sleep eight hours and have insomnia. It's not the number of hours. It's more how much you're struggling with sleep. How bad is your relationship with sleep? So are you lying awake for two hours every night,

anxious and frustrated and waking up feeling like you got run over by a truck and you're dragging your feet through the day and you're just feeling so irritable and cranky? I mean, that's a problem. You know, if it's interfering with your functioning, if it's really putting a damper on your day and your ability to function. And, you know, a lot of my patients say, if only I didn't have insomnia, I would go out and date. If I didn't have insomnia, I will go to the gym or I would travel. You know, these are things that make our physical and mental health better, right? Social companionship and having fun and doing the things that are meaningful to us. So if insomnia is getting in the way of you doing that, then it's detrimental to your health.

Are there other ways that longitudinal studies or other observational studies have shown that there is some cardiovascular or metabolic effect of having years and years, decades and decades of insomnia? Yeah, this is a tricky question because the way that we do research on insomnia, if we follow people over years to see, you know, if they started out with insomnia, how are they doing with their health? you know, seven, 10, 20 years later. The problem is we don't know what's the chicken and what's the egg. Is it the insomnia that's causing the hypertension 10 years later? Or was it some underlying cardiovascular risk factors that are causing insomnia? Or is it some third factor? For example, having experienced trauma, that's more likely to cause insomnia and that's more likely to cause hypertension. So is it some third factor, you know, that's causing both? So, you know, we can't do experimental studies to see if we give someone somebody insomnia, what does it cause? Because one,

that's unethical. And two, you can't really give someone insomnia. Insomnia is really sort of an internal generated state, whereas we can give someone sleep deprivation. We simply don't let them sleep for a couple of days and see what happens, right? So that's an innate methodological issue in the research, that's really, really hard to tease out. But I will say that, you know, the study we're working on at Duke right now is to see, you know, if we can give people cognitive behavioral therapy for insomnia to improve their insomnia, can we also improve their hypertension? And our hypothesis is yes, because the way your blood pressure works is it's supposed to dip at night. It's supposed to dip by at least 10%. But what we see is that often people with

insomnia don't have as much of a dip. Their dip is shallower. And we will, we will, want that dip to be deep, right? So if we can get someone to sleep more soundly and have less of that anxiety and that frustration at night struggling with their sleep, can we get their blood pressure to show the appropriate pattern, which is a healthier pattern? I want to make sure that I understand this distinction. So I'm going to offer a kind of thesis statement, and then you tell me how that thesis statement is wrong. Okay. So we need to distinguish between two ideas that we often conflate. Sleep deprivation and insomnia. Sleep deprivation is high sleepiness, but not enough bedtime. This is the thing that tends to have the most significant and obvious negative biological

health effects. Insomnia, which is low sleepiness, but often too much bedtime, tends to have subtler biological health effects, but it's still a societal scourge if people are consumed by anxiety, can't live a normal life, and go through their days, not feeling like themselves because they haven't gotten the kind of high-quality rest that they're seeking. Couldn't have said it better myself. That's perfect. And one little thing I would add, too, is that we know for a fact there's very close links between mental health and physical health. So even if the insomnia itself is not causing some sort of physical health problem, just the amount of time we're spending being anxious about sleep when we have insomnia,

I mean, anxiety has well-known physical effects. Right? So, you know, often I'm just, it's just so ironic because it's the fear of having insomnia itself that's keeping people up and causing the insomnia that is then making them really tired the next day or cranky or, you know, have GI issues the next day. So, yeah, it's a really tricky thing to tease out. We're going to get to solutions. I promise listeners that are now desperate for solutions. We're going to get there. I still want to understand a little bit more about the science of sleep. Sure. For relatively intelligent people trying to improve their sleep, what do you think is the single most underrated aspect of sleep science and our bodies?

I think the most underrated thing that we should be shouting from the rooftops is circadian health. So circadian rhythms are our biological clocks. And we all have them just innately. We have our master clock in our brain and then peripheral clocks throughout our bodies. even our individual cells have clocks. So our entire bodies run on these rhythms that hopefully run in sync with each other and on a regular pattern. So, you know, ideally you're sleeping and waking at about the same time every day, eating your meals and doing your activities at about the same time every day. You're getting lots of light during the day, not much light at night.

This is kind of how our pre-industrial ancestors lived, right? And so we all have these innate rhythms that are, you know, actually not 24 hours long, you know, to match the rotation of the earth. They're actually more like 24.1 to 24.3 hours long, which means that if I stuck you in a cave and gave you no indications of what time it is, over the course of a week or so, we would see you just naturally go to sleep and wake up about 20 minutes later every day until you went all the way around the clock. How did that happen? I feel like our bodies are like so exquisitely architectured by biology and natural selection and evolution and the fact that we've been on the same planet for several hundred thousand or million years. Is there a scientific explanation for why our circadian rhythm thinks of the day as being 24.3 hours long when obviously the day is 24 hours long?

You know, I don't think we have a really good answer for this, but I mean, we can always speculate on a sort of evolutionary level. And by the way, it's not 24.3 hours for everybody. You know, we have natural variation. There are some people whose circadian clocks are less than 24 hours long and some that are 25 hours long. So the 25 hour long people tend to be night owls. These are the folks who like really have to remind themselves to go to bed and they always want to be. staying up a little bit later. Whereas the shorter phase people are the ones who are getting so sleepy at 9 p.m. They're having trouble going out with their friends, you know, for like a late drink or dinner. So natural variation in the population is basically always good for a species survival, right? Because, you know, the more variation we have between us, the more bases we cover. So, you know, if everybody went to bed at the same time in the tribe, then of course the saber two tiger is going to come and just pick us off. one by one very easily, right? So we need the night watchmen.

We need the early risers to get the bow strung for the days hunting. We need variation, you know, all throughout. And it just so happens that younger people tend to have longer and later rhythms. And older people tend to have shorter and earlier rhythms. So I almost wonder if that's like an evolutionary thing where we want the young, strong fighters to be awake later at night to fight off the tigers or in like, and like, the wise elders to get up and start making the fire or something. I don't know. Oh, no, that's so interesting. Maybe it's just so story. Maybe it is the science perfectly. But the idea

that biologically, a tribe would thrive if it had a shift system sewn into their DNA and circadian rhythm, it would allow some of them to naturally stay awake to guard against the tigers and the foxes and the wolves at 2 a.m., while others would be perfectly enlivened at 2 p.m. in order to hunt the foxes and the wolves and the tigers in order to cook over the fire. That's really interesting. So it sounds like what you're saying,

to be honest, I always kind of assume that morning person slash night owl was kind of like zodiac signs. Like everyone just sort of made it up for themselves. It sounds like you're saying, no. Chemically speaking, morning people and night owls, this is real. If it is real, what makes it real?

Like, again, scientifically, chemically speaking, what makes someone a morning person or a night owl? Yeah, so you've probably heard of melatonin. Melatonin is this hormone, timekeeping hormone that we all naturally have in our bodies. And what it does is tell the rest of the brain and body that, oh, it's starting to be nighttime. So it ramps up in the evening hours and gets higher and higher and higher. gets reaches his peak during the middle of the night and then subsides in the early morning hours and it's like mostly gone by morning by the time you get up so it's basically our internal hormonal clock that keeps us on track now melatonin we call this the melatonin curve the rise and fall and the

shape of it and the size of it and everything that's the melatonin curve for some people their curve is just earlier and for some people the curve is later so you know for example if you're a morning person, your melatonin curve might start rising at like 4 p.m., 5 p.m. and get pretty high by 9 p.m. telling your body, oh, it's really time to wind down and start getting sleepy. Whereas I'm naturally a night owl. Mine maybe doesn't start rising until like 7 or 8 p.m. and doesn't get really high until midnight or later. So that's just our, you know, biological signal to keep track of time and to, and it's really baked into our biology to tell us when to be sleepy and when to be awake. I'm very interested in my own circadian rhythm because in college and even throughout my 20s, I really was a night owl.

I found it very productive to set aside on weeknights, the hours between nine and midnight. And I felt like I got really great writing done then. Now I'm in my mid to late 30s. I can't be even barely productive after 8.30. I mean, like, every single system of creativity and product just absolutely shut up. the doors and locks it around 8.15, and I've just got nothing left to give. Which raises the question, can people purposefully change their circadian rhythm? Like, how elastic is circadian rhythm for individuals if, say, a night owl wants to become a morning person? Yeah, well, so first

of all, there are natural changes, even without trying to change your circadian rhythm on purpose. So, you know, children are notorious morning people. You know, like my three-year-old will come and peel my eyelids open at 6 a.m., you know. But then during puberty, starting in adolescence, we become night owls. That's why teenagers really, really need to have later school starts because they just, you can't just tell them to go to bed at 10 p.m. or 9 p.m. They literally can't, right? So then in your early 20s, too, you're more of a night owl. And then in our later 20s and in our 30s, we start to drift earlier.

So that totally matches your experience of what's already happened. It's also behavioral, too, because I bet you probably had a little bit more flexibility in your schedule in your 20s versus now you maybe have more family obligations or work obligations. So you probably have to get up early to get your day started. So part of it, you've already done to shift yourself to be more of a morning person. And then, you know, my favorite study on this is Kenneth Wright's study out of Colorado where he took morning people, like biologically morning people, biologically night people, took them all camping for four or five days. And Colorado's beautiful camping country. And they didn't have their electronics. So they had no light, artificial light after sunset.

They just had their campfires. And they were out and about hiking and doing stuff during the day. So lots of sunlight during the day. After those four or five days, everybody came back as a morning person, like bonafide, melatonin curve, early morning person. So it is elastic. We can change. And that's built into our DNA too because imagine if we were so rigidly set in our ways

that we can't respond to our environments to the changing seasons and the length of day and all of that, right? We do need to be able to change along with the cues that we're getting primarily light, because light is a thing that your brain really needs to tell. when it's day and when it's night. It seems like for people that are interested in riding their melatonin curve for the purpose of being productive, and I'm not suggesting that the only reason to pay attention to one's melatonin curve is to maximize productivity, but it seems like one implication of what

you're saying is that if people pay really close attention to their energy levels, their melatonin curve, maybe if they consult with a sleep doctor as well, it might be really instructive for them to learn when do you have the kind of energy that would allow you to be a really productive writer or really productive researcher versus what parts of the day make more sense to slough off toward, all right, now go to the gym because your mind's going to stop working. Now do this other activity because you've got no energy left in your brain. In your clinical work, do you sometimes help counsel people to figure out what windows of the day are best to do? suited for a certain kind of activities?

Yes, I always say work with your body, not against. So whatever, and you know, you don't even need to go to a clinic and do melatonin profile to really figure out what type of chronotype you have. If you just honestly ask yourself, if I had a two-month-long vacation, when would I naturally wake up and go to sleep? Or, you know, if you ask a young person, you know, if you had to take the SAT tomorrow, Would you rather take it at 8 a.m. or noon or 8 p.m. And resoundingly, they'll probably say the afternoon or evening, right? So it's like, it's actually pretty easy to tell what kind of prototype you have. You know, if you have the privilege of having a flexible work or school schedule. Now, lots of people, of course, don't have control over their schedules. And that's, that's really tough, especially for shift workers and early morning shift workers. They really, really have it very tough, not just on their cognitive functioning, like how creative and productive they can be, but also on their bodies.

Like we know for a fact, we know from many years of research that, you know, nurses who have done more night shift work are more likely to have breast cancer. And we know that shift workers are more likely to have cardiovascular disease. So it is truly, and in fact, shift work is the only non-chemical carcinogen on the list of known carcinogens. So, you know, it's really, it's a tough question because whenever I can counsel a patient to say like, oh, negotiate with your boss to start your date later so you can live your best life as a night owl, that's all well and good if they have that privilege, but many people just don't have that option. I've read in several places that a handful of extreme high performers simply don't need very

much sleep. Like there is this like special class of human beings that can thrive. with extraordinary energy and no caffeine on something like three, four hours of sleep a day. Is that real or is that largely a myth? It is largely a myth. I mean, it is real to the extent that, you know, it does exist exceedingly rarely. And I would say most of these people

who are bragging about four hours of sleep and functioning great as the CEO of whatever company, either they're lying or they're actually doing more damage to their body and they're not functioning as well as they think they are. So, for example, I've had cases of people who are like, yeah, no, I did perfectly fine on four hours asleep as an eye banker in Manhattan throughout my 20s. But now my hair's falling out. You know, I have ulcers. You know, I have digestive issues. I can't remember people's names.

It's like, well, you know, that it adds up, right? Like even if you don't feel the negative effects necessarily because you're pounding red bulls and you're living a fast-paced life that keeps you on your toes, doesn't mean that there's not real damage being done. And, you know, for example, we have studies on young adults especially where the less they slept the night before, the more unreasonably rosy they were about their own performance the next day on like reaction time tasks where they said, you know, yeah, I perform perfectly fine. but they were totally overestimating their performance. Whereas the people who actually slept more, but maybe had insomnia or like didn't feel like they slept enough, were unsure about their performance, but they actually perform better.

So basically, the less you sleep, the cockier you are about your performance and the more wrong you are. Which implies that when people barely sleep and say, I'm still high functioning, we should say your impression that you're high functioning is actually a delusion, created by the fact that you barely slept.

Like their judgment about their judgment is hurt by sleeping less. Yep. That's so interesting. I didn't realize that. That's a real interesting finding. I know that you do a lot of work around perinatal sleep, that is sleep among new parents. And there's a conventional wisdom here that when you have a kid,

sleep is just going to suck for a while, period. Like sleep just sucks when you have. a new child, and that is just an immutable law of life. What is your take on the relationship that modern Americans have with perinatal sleep? I think that conventional wisdom is not totally wrong, because sleep does change, right? When we're pregnant, when we have babies, just inevitably, everything gets shaken up. Your schedule is different. You know, what you're responsible for is different. Your biology is different. Everything's different. So, of course, sleep is different too. But I think we maybe don't realize that there are things we can do to help

or at least to make it suck a little bit less. And I think the reason we don't know about this is because we just take for granted that moms are martyrs, right? We put our kids first. You know, we suffer. The more sacrifice we make, the better moms we are. And we just don't really pay attention to, you know, studying perinatal sleep, sleep during pregnancy and postpartum. And, you know, whatever research we do have is not really broadcast out there. Like, for example, you know, I've had two kids. I have a one-year-old and three-year-old. During both of my pregnancies, I had top-notch prenatal care from Duke University Hospital, just literally the best you could probably get in the country. And nobody told me that the half-life of caffeine can quadruple or more

during pregnancy. So it can go up to more than 15 hours, meaning if you chug one cup of coffee at 9 a.m., half of that caffeine could still be in your system by midnight. Now, if you, so if you stick with drinking coffee the same way that you did before pregnancy, you may not realize it, but that caffeine is staying in your system much longer. So then, of course, that will affect your sleep, right? And nobody told me that. I found that out on my own after I've already had two pregnancies with insomnia. So it's just stuff like that that I'm astounded that we don't even pay attention to and don't help, you know, arguably I think moms are maybe some of the most important, maybe, yes, the most important people. And also during pregnancy and postpartum,

this is maybe our best opportunity as a society to really improve public health is from the ground up, from, you know, the life-giving force of moms. If we take care of them, we take care of everybody. right? And sleep is so foundational. You're a sleep researcher who has had two children. So I'm interested because I know that some scientists my life sort of treat their different children like, you know, control groups. Did you change the way that you slept or that you thought about your sleep and your baby's sleep between child one and child two? Absolutely. And, you know, this is almost embarrassing because by the time I was pregnant with my first child,

I was already a board-certified behavioral sleep medicine specialist, and I had been doing research on sleep for years. So you would think I, of all people, would know better, right? But nobody told me. Like, even in my professional work, this was just not a topic. So I definitely did not have a good time with sleep the first time around. I had all the sleep disorder symptoms like hallucinations, sleep paralysis, nightmares, insomnia, you know, daytime sleepiness, all the bad stuff. So then for my second child, I really concertedly did more targeted research and did a lot of sort of self-experimentation. And it went a lot better the second time. And the main change that I made was that for my second child, I prioritized my circadian health. So practically, this is what it meant. The first child, you know, I listened to the whole nap when your baby naps, just get as much sleep as you can, right? So I split the night shift with my husband and I took, you know, like 7 p.m. to 4 a.m. I slept, and then I was awake and just started my day with a baby at 4 a.m. And he slept from

4 to 11 a.m. And I just snatched napping whenever I could during the day. Now, as I told you before, I'm naturally a night owl. So that whole like seven to four sleep was totally misaligned with my preferred, you know, midnight to 8 sleep. It was totally off. So whatever I sleep I did get was not good quality sleep. And my functioning during the day was awful because I was waking up multiple hours before sunrise, which my body was just so confused by. And snatching naps at random times during the day affected my nighttime sleep and further messed up my circadian health. So I was just, I had postpartum depression. I was like physically not feeling well. I had all sorts of infections like constantly. It was just a really terrible time. So with my second child, I prioritized my

circadian stability. So I went to bed exactly, you know, when I would normally go to bed. I got up and I got lots of light during the day, you know, same time, same wake up time every day. And I napped at the same time every day. I still allowed myself a nap, but I scheduled it. And I allowed the baby schedule to sink to me rather than me chasing after the baby schedule. And this way, we actually both synced up better, and my second baby slept better and learned to sleep through the night earlier than my first baby, too. So all around, and I already had a toddler running around the house. So all around, even with a toddler, I was feeling better, performing better. I wrote a book, you know, like during that pregnancy, everything just went better when I prioritized my circadian rhythm.

Oh, and by the way, a lot of moms are agonizing over, should I breastfeed or not? Should I nurse or not? because if I don't, maybe I'll get more sleep. But one really cool thing is that when you nurse, you have more prolactin. And that gives you more deep sleep, like a lot more. Like it doubles, possibly triples your amount of deep sleep percentage during the night. So it's kind of like your brain's way of saying like, sorry that you have to wake up at night. Let me make up for it, you know, with this extra deep sleep. And so that's what I did with my second child too.

With the first one, I really tried to get my husband to feed bottles at night. And that mess with my supply and everything, too. But with the second child, I just, I was like, forget it. I'll just get up a nurse whenever needed during the night. And I actually ended up getting more and better sleep. That's so interesting. So if there's like kind of a Dr. Wu guide to new parents trying to eke out enough sleep, it goes, number one, try as much as possible to hold fast to the sleep schedules that you've carved out before

the baby is born, riding your circadian rhythm rather than trying to fight it. Number two, trust, and this goes a little bit to anxiety, trust that even though sleep will be interrupted in the middle of the night for feeding, nursing actually increases deep sleep percentage, especially for the mother. And so there can at least be a little bit of a trade-off there. And three, to the extent that Parents are going to nap because having a newborn is exhausting, try to nap the same time every single day to continue to regularize that circadian rhythm and regularize when your body wants to dip out of consciousness and then go back to wakefulness. Precisely. And I would just add that for the nap, like midday or early afternoon would be ideal. Like pretend you live in Greece and you follow the

siesta schedule, right? Just do that. And even if you don't fall asleep, rest. You know, that's a really good time to rest. So then your body gets into a rhythm of at least decompressing a little bit and, you know, sort of de-arousing a little bit. Because when you're a new parent, there's just a lot of anxieties, a lot of like, ah, I don't know what to do, you know. So give yourself a chance to decompress, maybe take turns with your partner or a helper. And that rest goes a long way, too, towards improving your nighttime sleep. Because if you are going, going, going all day, when you're a new mom,

that message that you're sending to your body is that there must be a saber-two tiger chasing you all day long. Because otherwise, why would you be, you know, four weeks postpartum and working this hard, right? So, you know, teach your body that it is safe. It's okay to relax. And, you know, let's actually take time to decompress and allow your nervous system to come down a little bit.

I want to finally get to solutions for everyone. We have talked in this show a little bit about CBT. That's cognitive behavioral therapy, which is one of the more popular forms of empirically verified clinical therapy and practice today. You study CBTI. That is cognitive behavioral therapy for insomnia.

First off, can you just define CBTI? What is that? CBTI is a non-medication therapy. that improves your relationship with sleep for people with insomnia. So the way I like to describe it, it's kind of like doing physical therapy, but for your sleep. So it's, you know, time limited. It doesn't go on forever. It's usually like four to eight sessions or so, meeting with a CBTI specialist.

And it's very hands-on. It's very tailored to you because, you know, 10 different people with 10 different broken ankles, you might have to treat slightly differently. Same thing with insomnia, right? So it's very data-driven and it's very personalized. And it's very homework practice-based. Because just like you can't improve your broken ankle by only meeting with your physical therapist once a week, you can't improve your sleep by just meeting with your sleep therapist once a week. There's a lot of practice at home, a lot of changing your schedules, trying different skills and tools.

And, you know, at the end of this, you are hopefully not only sleeping better, but you have such a good relationship with your sleep that you can weather changes and challenges in the future. You take those skills with you forever. So let's say I'm a patient. Let's say I come into your clinic or I enroll in your Duke Sleep Bright study. And I say, Dr. Wu, I'm 36. I'm a 36-year-old writer podcaster with a long history of insomnia. This is true. I've struggled falling asleep for many years.

Lately, my issue has been more that I wake up in the middle of the night and I can't fall back asleep. And just to speed things along here, you know, because you're going to ask a few details about my life and my habits and my stress. I'll just, I'll just throw it at you right now. I'm married. I'm a bit of a workaholic. I generally have lower than average externalized stress symptoms, but in terms of internalized stress symptoms, who knows? I have strong social relationships. I do keep my iPhone in my room. I drink a moderate amount, say, a glass of wine, or it's equivalent with dinner every other night and then more on the weekends.

I do not smoke cigarettes. I have very occasional marijuana use and I do not drink enough water ever. I don't know if that last part is clinically relevant, but my wife would want me to be honest here. Where would CBTI start for someone like me? That's a very good case summary. Thank you for that.

So I would start by asking you to keep a sleep log. So information like when did you go to bed last night? night, when did you turn out the lights to try to sleep? How long did it take you to fall asleep? How long were you awake during the night? When did you wake up for the day? When did you get out of bed for the day? Basically, if you give me these, I think, seven or eight pieces of information and keep that for a week or two, then we can see a lot of patterns and we'll see a lot of really useful data that we can work off of. So, for example, if I see that you are consistently having trouble falling asleep and you're taking like an hour or more to fall asleep, the beginning of the night, I may start to wonder, are you going to bed too early for your

chronotype? Are you maybe biologically more of an evening person, a night owl, than you have sort of designed your life around? So maybe we try to shift you a little later. Sometimes it's as simple as that. But if I see, for example, that you have more middle of the night awakening, which you're nodding your head, that's like what's what you've been experiencing, then I want to see, okay, how much time are you spending in bed? We can. We can't. days versus weekends, you know, are there some assumptions baked in here? Like, are you going to bed for always, you know, eight and a half hours a night? And I would ask you why eight and a half hours specifically? You might say, well, shouldn't I get eight hours asleep every night? Then we will

talk about how everyone's different and you may or may not need eight hours. Even if you did 10 years ago, you may not now. So, you know, one of the big pieces of CBTI is called sleep consolidation. And It's basically making your pizza smaller. Like if you're making your pizza from scratch and you have this much dough, but you stretch it too thin to fit like a huge pie, you're going to have holes in the crust. You don't have enough dough to go around, right? So what if we just squeeze a pizza smaller, make a Chicago deep dish style, you know, have you be in bed for a shorter amount of time to teach your brain to fill up that time with good quality sleep? Because quality always has to come first before you can sleep more. you may or may not need to sleep more,

but at very least we need better quality sleep, right? It seems like a very useful piece of counterintuitive wisdom that a lot of people think, Omnis, I have insomnia, therefore I need to focus on going to bed. But in fact, a lot of insomnia comes from too much bedtime. It comes from centering the bed and the bedtime too much in our lives,

to extend your analogy. We're making the pizza too large. And if we constrict our bedtime a little bit, I think the word you used was consolidate, we're going to feel higher sleepiness. And that higher sleepiness is going to allow us to not only fall asleep faster, but also maintain sleep throughout the night. Is that right? Right. Yes, not only more sleepiness is going to be achieved through this, but also lower hyperarousal. Hyper arousal just means your mind or body are too revved up for sleep. And the way we're decreasing arousal is, well, think about when the worst of your experiences, with insomnia. When you're lying there awake for a couple hours during the night, you're staring at the ceiling, you're like feeling resentful that your wife is sleeping peaceful beside you, you're wondering if you're going to get dementia from this, you're anxious, frustrated. Is that helping you go back to sleep?

Right. So if we actually spend less time trying, because the trying is really sometimes the worst thing we can do when we have insomnia, you know, if we just take the trying off the table and drop that rope don't play tug of war anymore with sleep, then sleep is actually more likely to come to us. So, you know, I always teach that, you know, your relationship with sleep is what we're focusing on here. And if you want to have a good relationship with sleep, you're not going to be that overbearing, like, you know, creepy ex-boyfriend that like tries to chase down sleep and monitor sleep and is really on top of sleep and aggressively says you have to show up exactly when I want you to, where I want you to, I mean, that's not a good recipe for a relationship.

Whereas if we lay back, create our environment that's welcoming for sleep and actually have realistic expectations and flexible forgiveness for our sleep to be, you know, not a perfect robot, then sleep is actually more likely to be your friend and come to you when it wants to. And your friend is a very good, loyal friend, so she will take care of you if you just let her. I've had it really interesting how different approaches clinically and psychologically, can have different effects on people. Because I can imagine that for some people, imagining their relationship with sleep

as a relationship with a friend is incredibly useful for clarifying the kind of relationship they want to develop with their sleep. For me, I'm a little bit more asocial in the metaphor that I prefer. I just want to know, like, if I go to sleep at 10 p.m.,

and I wake up at 7 a.m., and I am dealing with severe middle of the night insomnia, what do I do in terms of time in bed. And there, you know, someone in your position just might say, well, look, if you're trying 10 to 7 and it's not going well, try 1030 to 630, right? Try 11 to 7. Shrink the pie of sleep, and that might sort of concentrate the sort of the sleepiness molecules so that they're like a little bit more active. Yeah. I do want to ask another question about middle of the night insomnia,

which is sometimes called bifasic sleep. I mean, I am just so interested in the science of this and why our bodies seem in some primordial way to want to wake us up in the middle of the night. Can you tell me a little bit about what you understand to be like the science of our sleep drive and why our bodies might in some chemical way want to break up the night like this? Yeah, so naturally we all actually experienced two halves of the night, whether or not we realize it. The first half is when most of your deep sleep happens or also called slow wave sleep. And that's the sort of the money sleep. That's the thing that boost your immune system and heals your injuries and clears out the brain toxins. That's a high priority sleep that your brain wants to get done in the first half of the night.

And that's driven by your homeostatic sleep drive. On a chemical level, this is the accumulation of something called adenosine in your brain. So throughout the day, as you're awake going about your business, adenosine is accumulating, accumulating, accumulating. It's kind of like a bank account marking how long you've been awake so that your brain knows how much sleep you need to sort of recover from that amount of being awake. So the more denocene you have, the more deep sleep and more sleep you're going to get. But once you're sort of halfway through the night, you've basically burned through most of your adenicine and you've gotten your deep sleep done. But the second half of the night, it's still, you know, not time to get up yet. So the second half of the night is driven by your circadian rhythm, which we've already talked about as being your body clock.

So your body clock knows, you know, melatonin is so high, it's still the middle of the night. So let's keep sleeping. So those are the two natural halves of your sleep. Now, sometimes the baton gets dropped between these two legs of the relay race. And there's nothing wrong with that because in pre-industrial times in Europe, for example, we have. plenty of documentation that people used to just get up as a matter of routine in the middle of the night and sing songs, have sex, like get the bread rising for the morning. There are still cultures in the world that get up in the middle of night to do yoga or to pray. So this is reflective of a

natural biological thing that happens. But now in our modern capitalistic, industrialized world, we kind of expect our sleep to be squeezed in together for like those eight consolidated hours so we have more time to work and do other stuff, right? And now that we have artificial lighting and blah, blah, blah. So now we expect ourselves to sleep through the night. We ask new parents. Like the first thing we ask is, oh, is the baby sleeping through the night yet? As if that was the gold standard of what should happen as early as possible. But it doesn't have to be like that. You know, if you just naturally, wake up at 2 a.m. every day, and that's just what happens, but you still get enough sleep overall, and you're functioning well, and you're feeling well, you're healthy, your relationships are fine, then by all means, just do by phasic sleep, as if you were, you know, pre-industrial person in the whatever in Ireland, you know, just do that. It's interesting, yeah, because when my wife and I wake up at 2.30 a.m. and start blasting Taylor Swift and singing midnights, the neighbors don't seem to appreciate it. And I'm like, come on, people. This is just medieval by phasic sleep.

This is what our homeostatic sleep drive wants to do. How are you so ignorant as to not understand our need to sing Taylor Swift at 2 a.m.? I don't know if medieval people had Taylor Swift. They were clearly missing out, but... They had her essence in their hearts, I think. She's eternal enough. I want to end with some with a rapid fire round, where I ask you about some of the trendier sleep pack suggestions and you give me an expeditious, do it, skip it, or don't know enough, with maybe just like a brief elaboration. Before we start this round, I know that any good scientist in your position is going to want to offer the caveat that we're talking about averages here and some things work for some people, some things don't work for some people. You know, if playing

death metal at midnight put someone to sleep, that's fantastic, but like, you know, you're not going to prescribe slip knot and insane clown posse to insomniacs. And, you know, that's just the Usually not. Usually not. Right, exactly. Everyone is different. Okay. So we're going to do five of these.

Number one, sleep trackers. That is not only the things that you wear on your arm, but also a kind of, and I hope I'm not stacking a deck here, obsession with returning to one's sleep number to visit or measure the quality of sleep over time. I am super excited about these as a sleep researcher. And I think for many people, it can be helpful to show your overall patterns. But with a caveat that we don't want to get too attached to these numbers because they are not necessarily fully accurate. And also, there's nothing you can change about your percentage of REM, for example. So, like, why track it? So just don't make it more anxiety-provoking than it needs to be.

I do think that the kind of people who are probably most likely to use sleep trackers are the sort that are anxious to know what number is spit out by the tracking of their sleep. So I'm clearly revealing my horrific bias here. I'm way against sleep trackers and too many listeners for whom sleep trackers have been revelatory

in your life, good on you. They did the opposite of work for me. Number two, viewing sunlight very early in the day. Yes, love it. It doesn't necessarily have to be early in this. day, any time during the day is better than not, more sunlight during the day better. And why is that again? Because that tells our circadian rhythms when it's day and when it's night. And the less

confused it is about the timing, the better quality sleep and better quality wake your brain is going to give you. That's right. Because deep down inside all of us is a caveman in a cave without access to sun that wants to wake up 20 minutes later every single day. So we have to interrupt that sort of chrome magnet vestige that's inside of us. Number three, lettuce water. So you would have to eat a truckload of lettuce in order for there to be any sort of sleep effect. So probably no. And maybe unpacked just a little bit about why I just said lettuce water?

Because this is a TikTok trend that got really popular. And it's based on these studies in mice where these mice got lettuce seed concentrate. So think about how small a mouse is and how much of that chemical is in that concentrate. So if you extrapolate that to humans, we would really have to drink like a truckload of lettuce water for that to have any equivalent effect. And by the time you drank that much water, you've spent all night drinking lettuce water and not sleeping. So strong no on that one. Number four, taking Advil PM every night if you have trouble falling asleep. Oof, I know for some people this feels like the only option, and I certainly don't judge that.

Long term, this is probably, I don't know about the medical effects, but long term this probably will have psychological effects such that you develop psychological dependence on taking something to fall asleep and you lose confidence in your own ability to sleep. Number five, watching the same TV show every night to fall asleep. Sure, why not? You know, we all have our sleep associations, whether it's like taking a shower or having white noise. If you like it, sure, no problem. Any sleep routine that you have, that just personally has worked really up well for you.

But I'll share first to get the ball rolling. I tend to fall asleep very easily now, and that was not always the case. And for whatever reason for me, the answer was rewatch an episode of television that you've watched at least 50 times before. I find it so relaxing

to have a little 10-minute ritual where I dip into like a little bit of TV on my iPad that I have absolutely no anxiety about how things are going to proceed. I can tell you every single line of these TV shows, Arrested Development, I'm Breakable Kimmy Schmidt, V.

I can tell you every single line. Thank you. Yeah. It's not about enjoyment. It's about, as you just said, this sort of queuing to begin to really, really come down that curve of wakefulness. Yes, it's about queuing the beginning of your wind down. It's also about taking up just enough of your attention that your mind doesn't go to anxious places that then ends up spiraling. It's almost like, you know, counting sheep is not good enough because that's too easy.

Your mind will start spiraling anyway if you're prone to. worry. But if you do some math, like, you know, go down by 13th starting from a thousand, then it just hard enough that it takes enough attention that you let yourself, let sleepiness come to you before your mind starts spinning. So watching like, so watching an episode of friends, for example, you know, would be perfect for that too. The other thing about counting sheep or even these other sort of really boring activities that sometimes people encourage insomnia actually do at the beginning of falling asleep or in the middle of the night is that it's just that they're boring they're not fun i don't want to have an aversive relationship to anything surrounding sleep if in the

worst case scenario i can't sleep i want to look forward to that in a small sense like oh i can't fall asleep i'll just watch a little bit more of veep and i won't be you know counting sheep i'll be counting you know profane words um because it's an incredibly profane show but the fact that it's a little bit fun without being particularly arousing, without being particularly thrilling, because I've watched these episodes 50 times already, means that, or at least it's helped me to reduce my anxiety in the event,

in the sometimes inevitable event, that I have a broken up night. I think you really put your finger on and help me articulate why it's been so helpful for me. Yeah, absolutely. You know, I actually am a little bit of a rebel in this sense in the sleep researcher community were a little split on this. Most people say do something relaxing and boring to help yourself,

you know, get back into sleepiness. But I say, honestly, do whatever you enjoy, even if that's playing a video game. You know, like usually it's not going to be playing a video game for most people, but don't sit there and read a phone book or like listen to the most boring book ever. You know, do something fun and enjoyable. The whole point is that we don't want to be afraid of nighttime. We don't want to be dreading the act of being awake during the night because there's nothing inherently wrong with that. We just have a little extra me time to enjoy. And if you feel that way, you're, you know, ironically, actually less likely to wake up or stay awake for a really long time because there's nothing inherently threatening about being awake. You get to look forward to it.

Dr. Jade Wu, thank you very, very much. Thank you so much for having me. This was fun. Thank you for listening. Plain English is produced by Devin Manzi. If you like the show, please go to Apple Podcasts or Spotify. Give us a five-star rating. Leave a review. And don't forget to check out our TikTok at Plain English underscore. That's at Plain English underscore on TikTok.