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How sleep affects your health with Molly Atwood, PhD


AMA Update covers a range of health care topics affecting the lives of physicians, residents, medical students and patients. From private practice and health system leaders to scientists and public health officials, hear from the experts in medicine on COVID-19, medical education, advocacy issues, burnout, vaccines and more.

Are you getting enough sleep? How much sleep is good for your health? What are the benefits of napping—or are naps bad for you? In today’s AMA Update, Molly Atwood, PhD, assistant professor of psychiatry and behavioral sciences at the Johns Hopkins School of Medicine, dives into the science of sleep medicine to answer those questions and more. AMA Chief Experience Officer Todd Unger hosts.

Read 8 things doctors wish patients knew about healthy sleep habits.


  • Molly Atwood, PhD, assistant professor of psychiatry and behavioral sciences, Johns Hopkins School of Medicine

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Unger: Hello and welcome to the AMA Update video and podcast series. Today we're talking about sleep, specifically how many of us are not getting enough of it and what exactly we can do about that. I'm joined today by Dr. Molly Atwood, an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins School of Medicine in Baltimore. I'm Todd Unger, AMA's chief experience officer in Chicago. Welcome Dr. Atwood.

Dr. Atwood: Thank you, Todd. It's wonderful to be here.

Unger: Well, as we were talking a little bit before, one can't help but look at the news and see all of the stories about sleep. Must be in the zeitgeist out there, so to speak, and more and more learning about that. In fact, over the years, study after study has reiterated what the long lines at Starbucks remind us of every day—we're not getting enough sleep. So let's talk about, how much sleep debt does the average person have, and has it gotten worse over time?

Dr. Atwood: I think that's a really important question, Todd, and what we see when we look at large-scale surveys of healthy adults, both within the U.S. and countries in Europe and Asia, is that there's actually no consistent data to suggest that the average sleep duration has decreased over the past several decades. But having said that, somewhere around 30% of healthy adults are regularly getting six hours of sleep or less.

And in particular, data from the U.S. suggests that, although the mean sleep duration may have actually increased slightly over the past 40 or so years, the proportion of these short sleepers seems to have also increased. So the proportion of folks with short sleep duration, specifically, is on the rise. And this is important because numerous epidemiologic and laboratory studies looking at the relationship between sleep duration and indices of health, as well as all-cause mortality, have demonstrated that the optimal range for sleep is around seven to nine hours.

When we see the average sleep duration go below or, interestingly, also above that range, we start to see a greater association with morbidity and mortality.

Unger: Well, those definitely sound some of the consequences of not getting enough sleep. Can you tell us a little bit more about some of the other health consequences of not getting the proper amount?

Dr. Atwood: Yeah. So sleep is extremely important for almost every system in our body, so insufficient sleep can impact your health, really, in a myriad of ways. I think the most important would be that sleep is vital for cognitive function across the lifespan. So this means memory, concentration, attention, reaction time, judgment, and this obviously has implications for motor vehicle, industrial and medical errors, accidents.

And we also know that insufficient sleep can contribute to or accelerate cognitive decline and dementia as we age. Insufficient sleep also negatively impacts our metabolic health via impaired glycemic control and increased risk of diabetes, and there's also a really strong relationship between insufficient sleep and cardiovascular health, whether it be hypertension, coronary artery disease, heart attack, arrhythmias, stroke.

And sleep loss can also really profoundly affect our mood and even predict depression over time. So adequate sleep is really one of the pillars of a healthy lifestyle.

Unger: You may not know it, but I'm the king of napping. Question for you. So for those folks who've had a bad night of sleep, you drank some coffee. It's still not kicking in yet. Can a nap help you recover?

Dr. Atwood: That's a great question and I think to answer that it's important, first, to highlight the difference between acute or short sleep loss, as you're referring to, and chronic sleep loss. So acute sleep loss means a poor night of sleep, maybe up to a week of poor sleep, and this is actually really common now and then, even for the best of sleepers. And that's OK because our sleep systems are designed to compensate for acute sleep loss without us having to do anything.

And what I mean by that is if you get less sleep, and you need one night, the following night, your body will actually compensate by spending a greater percentage of time that you are asleep in the most important stages of sleep—REM sleep and deep sleep. So there's this natural compensatory mechanism there to ensure that we're getting the type of sleep we need to recover and function optimally.

But until we get that recovery sleep, we do know that after a fortnight, mood and cognitive functioning will be somewhat impaired. So there are certain instances where naps can be helpful or even important. For example, for folks who are in certain industries or job positions like commercial drivers, physicians, pilots, a short nap can actually immediately improve things like alertness, reaction time and recall close to baseline functioning.

On the other hand, when you experience chronic insufficient sleep for a period of months to maybe even years, napping is no longer going to help you fully overcome the deleterious effects of not prioritizing adequate sleep. And furthermore, it will take some time getting consistent adequate sleep again to see a return to baseline and things like cognitive function.

Unger: So for that former category, and that is the not-long-term sleep issues, is there an ideal nap time?

Dr. Atwood: Yeah, that's a great question, too. So if you need to take a nap, I think in terms of duration, keep it short—around 30 minutes. If you sleep more than 30 minutes, you're more likely to go into deep sleep, which could make it more difficult the following night.

And the ideal timing of a nap would be around seven to nine hours after your typical wake time, when we tend to have a natural dip in alertness and are thus more likely to be able to fall asleep and capitalize on the nap.

Unger: Is that about between two and three, when I feel like sometimes a truck hit me?

Dr. Atwood: For the typical sleeper, yes.

Unger: OK, good. I think we're learning a lot, too, about that things that interfere with sleep, and interestingly, one of the things that's coinciding with learning about effects of alcohol on the body, I know that is a pretty significant inhibitor of quality sleep. Can you share more about that?

Dr. Atwood: Absolutely. So alcohol can actually help us to fall asleep, but once it starts getting metabolized in our system, it fragments sleep and so reduces quality. And interestingly, now that cannabis is being legalized in more and more states—Maryland, in our last election, included—I think it's important for people to know that, specifically THC or the psychoactive component of cannabis, really accessing way on our sleep as cannabis does—or as alcohol does. Sorry.

And that it can help us to fall asleep, but it also really fragments or impairs the quality of sleep.

Unger: Really interesting. So let's talk a little bit more about best practices around sleeping and napping that doctors can share with their patients. Any other kind of dos and don'ts?

Dr. Atwood: Yeah. I do think that, especially when people have a busy lifestyle—they have many responsibilities—the first thing that tends to suffer is sleep. So first and foremost, I would say that it's important to understand your individual sleep need—so how much sleep you need on average to function at your best—and to make sure that you stick to that on a consistent basis.

It's also important to understand that it takes some time to prepare your body for sleep. So this means setting aside at least 30, if not 60, minutes to wind down before bed with relaxing activities only. So no work, no news, no intense planning or problem-solving, nothing physically taxing. And this should really be done under dim lighting and without exposure to blue or white light from electronics or LEDs, which suppress our body's natural release of melatonin and can keep us alert.

And then if, after getting into bed, you find that sleep is just not happening, get out and continue to do something relaxing until you feel sleepy again instead of staying in bed tossing and turning and feeling frustrated, which only makes the problem worse.

Unger: How much time should you allow before you say, I'm going to get up and give it another shot?

Dr. Atwood: The general rule of thumb is around 20 minutes, but what I typically tell my patients is, as soon as you start feeling like this is just not happening or start getting frustrated, that's the time to throw in the towel and go do something relaxing to reset.

Unger: Got it. Sorry I interrupted you. Keep telling us more about best practices.

Dr. Atwood: That's OK. I was just going to say that I think the other really important thing that not enough people stick to is a consistent into-bed and out-of-bed time, particularly wake time is important. And it's important for maintaining the timing of the body's internal clock or our circadian rhythm, and there's many systems in our body that follow a circadian pattern. So if you vary during the week more than an hour, it's not a big deal.

But if your schedule shifts by multiple hours several times per week, that's more of a problem, and unfortunately, my shift work increases the risk of developing health issues.

Unger: Now, I know one of the best things my wife and I did as part of the our New Year's resolutions is shutting the video off certainly by 9:00 and then reading for an hour. Consistent bedtime lights out at 10:00. That sounds like right in line with your plan.

Dr. Atwood: That sounds like an excellent routine.

Unger: Well, let's say despite getting a full night's sleep, doing these things, someone is not feeling rested or they always have trouble falling asleep or staying asleep, what should a physician be on the lookout for here when a patient comes in complaining of problems like this?

Dr. Atwood: Yeah. I think, in general, while it's OK to have an occasional poor night of sleep, there's also a lot of people out there who have a diagnosable sleep disorder. And that's OK, too, because we do have good treatments. So if people are getting a sufficient number of hours of sleep, and they're on a consistent schedule and they're still feeling tired, the first thing I think a physician should look for is potential sleep disorder breathing.

Sleep apnea is extremely common and would be the most likely explanation for those symptoms. So if somebody snores loudly, they have overweight or obesity, they're waking up gasping or choking for breath or are observed not breathing during sleep, it's a really good idea to refer them for a sleep study to confirm a diagnosis and initiate therapy. With respect to difficulty falling or staying asleep, the most common and likely disorder that would explain those symptoms is insomnia disorder.

And I think it's important for physicians to know that the first-line treatment for chronic insomnia is actually not a sedating medication. It's something called cognitive behavioral therapy for insomnia or CBTI. And in the short term, it's at least as effective as medication. In the long term, more so. It's also a relatively short-term treatment and doesn't have the potential risks associated with it that medications do, which makes it appealing to patients.

Unger: Without going into great detail, kind of at the top level, what does that involve?

Dr. Atwood: So cognitive behavioral therapy for insomnia is really grounded in the science of sleep. So an understanding of the systems in our brain that regulate sleep and how certain things that we do—for example, varying our wake time, spending way too much time in bed, using light in bed—can weaken or regulate our natural sleep systems. And so we work with people to really help reset patterns to optimize their natural sleep systems and to make sure that stress, anxiety, frustration or worry is not overriding their natural sleep at nighttime. So it's a very skills-based therapy.

Unger: Are there any other environmental factors that people could be overlooking when they think about what might be getting in the way?

Dr. Atwood: Yeah. Unfortunately, our sleep systems are very sensitive to a number of things, both internal and external. So things like pain or any kind of discomfort in the body, noisy bed partners, if you sleep with pets. Unfortunately, they can fragment sleep. Certain medications as well.

Depression and anxiety are extremely common, and a number of SSRIs can also interfere with sleep quality. And then even when in how much we eat or exercise in relation to our sleep can also have an impact.

Unger: I think I might get kicked out before my dog on that thing, so I'm learning to live with that particular interrupter. You've got an audience listening in on this particular conversation that are not unfamiliar with lack of sleep—med students, residents, physicians out there. A lot of late nights studying, a lot of late shifts. Sometimes it's just unavoidable.

What advice do you have for those folks who may not get the kind of access to sleep that they need?

Dr. Atwood: Yeah, I think that's another really important question. And I think my answer may be somewhat controversial to a medical audience, but in my opinion, I do think that the culture needs to shift somewhat. And that's not just in medicine, but I think in many fields, too. Support what we preach to our patients, which is to prioritize adequate sleep as a fundamental pillar of good physical and emotional health, because it impacts how we treat our patients and not just ourselves.

But having said that, for people who are already in that environment, there is some data to suggest that if you're really conscientious about other areas of health—so you exercise regularly, you eat well, don't drink to excess, smoke, and really take care of stress and mental health—that that can compensate somewhat for the effects of insufficient sleep, although not fully. And I would also suggest that if you are experiencing some sleep deprivation, go ahead and take a nap, especially before you go into a procedure, and to try to practice good sleep hygiene in terms of creating an optimal environment for sleep.

And then if you're still struggling, to see a sleep medicine specialist to see whether a more tailored treatment approach can provide additional support.

Unger: Dr. Atwood, thank you so much for joining us. It's so interesting. I know I'm putting a lot more emphasis on getting the sleep that I need. It doesn't make me feel exactly youthful, but, boy, do I feel better. And hearing your advice here is a lot of motivation.

If you'd like to learn more about this topic, make sure to check out the article in the description of this episode, called "Eight Things Doctors Wish Patients Knew About Healthy Sleep Habits." We'll be back soon with another episode. In the meantime, you can find all our videos and podcasts at Thanks for joining us today and please take care.

Disclaimer: The viewpoints expressed in this video are those of the participants and/or do not necessarily reflect the views and policies of the AMA.