Tweeting, not sleeping? What is your Social Media/Sleep Balance?

Photo credit: m01229 via / CC BY

Photo credit: m01229 via / CC BY

New research links social media and sleep problems 

Social media has become a fixture of modern life, a constant stream of information coming and going, and a way to stay perpetually connected. I love social media, it keeps me in touch with friends, family, and all of the people out there who are interested in learning more about sleep! But, have you ever wonder how all that Twittering, Instagramming and Snapchatting might be affecting your sleep? According to just-released research, time spent on social media may be seriously undermining nightly rest.

Sleep and the digital generation

Young people are among the most avid and heavy users of social media, and this latest research focused on the effects of social media engagement among young adults. The results strongly indicate social media use in young people is linked to sleep problems. Researchers at the University of Pittsburgh examined social media use and sleep in a group of young adults, and found that heavier users of social media are significantly more likely to experience disturbances to their sleep.

Their study included a nationally representative group of 1,788 adults between the ages 19-32. Researchers measured both the frequency and volume of social media use. Social media volume was a measurement of the amount of time spent engaged daily. Social media frequency was a measurement of the number of visits to social media sites over the course of a week. Researchers gathered sleep data using patient-reported information about sleep habits and experiences. So these data are subjective not objective.

The scientists’ analysis showed a strong correlation ( a relationship, not a cause) between social media use and sleep disruption. Among participants, heavier volume and frequency of social media interaction was associated with significantly greater likelihood of sleep problems.

  • The highest volume users of social media—those in the top 25 percent—had nearly two times the risk of sleep disruption as those in the lowest 25 percent.
  • The most frequent social media users—again, those young adults in the top 25 percent—had nearly three times the risk of sleep disturbance as those in the lowest 25 percent.

This study did not address what is driving the relationship between social media engagement and sleep. Is frequent, heavy social media use contributing directly or indirectly to sleep problems. Are people who have trouble sleeping more likely to be using social media more often than better sleepers? Or are both influences in effect? These are important questions that need to be the subject of additional study.

The impact of social media on health, sleep

Science is just beginning to assess the impact of social media use on health and well being. This current research is one of the first studies to draw a link between social media engagement and risk of sleep disturbance. But other recent scientific evidence has also provided insight into social media’s possible role in undermining sleep and health in young people:

  • College-age adults who check social media sites during typical sleeping hours are more likely to suffer daytime tiredness and cognitive impairment, according to research. They are also more likely to use sleep medications. (Other research shows that young adults are extremely likely to keep their phones or mobile devices near their beds, and are very likely to use these devices while in bed.)
  • A 2015 study of teenagers ages 11-17 found that social media use was linked to diminished sleep quality. Researchers also found social media use linked to lower self-esteem among teens, as well as to elevated levels of anxiety and depression. This study examined time of day as a factor in social media’s effect on sleep, and found that using social media at night was especially detrimental to teens’ sleep.

Links to depression, anxiety

Other research has demonstrated troubling associations between social media use and psychological health in children, teens and young people.

  • Frequent use of social media among children and teens in grades 7-12 has been linked to increased levels of psychological stress and diminished mental health, according to research. Higher levels of social media use also increases teens’ risk for becoming victims of cyber-bullying.
  • A recent study of more than 1,700 young adults ages 19-32, also conducted at the University of Pittsburgh School of Medicine, examined the link between social media use and depression. (This investigation involved some of the same researchers as the current sleep and social media study.) Researchers found that young adults with the highest rates of social media engagement were at significantly greater risk for depression.

Depression and sleep have a complicated, bi-directional relationship—that’s to say, each condition can significantly influence the other. People with depression very often have trouble sleeping, and people with sleep problems are more vulnerable to depression. The effect of social media on mood and psychological well being, in children and in adults, has important implications for sleep, but is not yet well understood.

Social Media/Sleep Balance

All of these studies, like the current one, draw compelling connections among sleep, sleep-related problems, and social media use. But none of them establish underlying cause. Given the outsized role that social media plays in the lives of most young people—and people of all ages—it is critically important we develop a better, more thorough understanding of how social media behavior is affecting sleep and health, if at all.

In the meantime, it is important to draw boundaries on social media time, and to help children and teenagers learn to do so as well. With such easy and unlimited access, it’s not difficult to understand how establishing and maintaining limits around social media might be difficult, but it is not impossible. You can have your tweet, post, or chat in a healthy way, it just about making a decision for balance in your social media world. Let’s call it your social media/sleep balance (like your work/life balance).

The Sleep Doctor Guide for Social Media/Sleep Balance:

  • Charge your mobile devices out of the bedroom (this way you cant hear it buzz in the middle of the night).
  • Stop social media use at least an hour before bedtime (this can be a tough one, try 30 minutes at first, then make it a little longer).
  • Replace this time, with light reading (not on an electronic device), simple stretches, meditation or deep breathing.
  • Don’t check Social Media in the middle of the night when you may wake to use the restroom or just get more comfortable.

Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™

For updates follow me @thesleepdoctor



A new, more sleep-friendly iPhone on the way? Its about time!

Photo credit: Hendrik Wieduwilt via / CC BY

Photo credit: Hendrik Wieduwilt via / CC BY

Apple takes steps to address the iPhone’s sleep-disrupting light

We learned this week that Apple is moving toward making its handheld devices more sleep friendly. Included in an upgrade for Apple’s iOS operating system is an app called “Night Shift,” which changes the color balance of light from device screens during evening hours. The Night Shift app uses GPS data and user settings to adjust the composition of screen light after sunset, reducing white and blue light while increasing red and orange light. The upgrade (iOS 9.3) and the app itself are not yet available to the general public, but are currently in beta testing.

The effects of light on sleep

What does color temperature of artificial light have to do with sleep? A lot, according to scientific research. Exposure to artificial light at night is one of the most widespread and significant disruptors to sleep. Blue light is particularly aggressive in its disruption to sleep and to circadian rhythms, according to a deep and growing body of scientific study. Digital devices—phones, tablets, computers, and other LCD screens—emit high concentrations of blue light.

The addition of this feature to Apple’s hand-held operating system is an important step in the right direction. Effective reductions to blue light exposure are likely to benefit sleep and overall health.  The company deserves acknowledgment for recognizing this health issue, and taking steps to integrate light controls like these into their handheld devices.

But the problem of light to sleep and health is bigger than Apple, and more pervasive than the ubiquitous smartphones that are so often shining brightly at night. As worthwhile a move as this is by such a high-profile company, it doesn’t—it can’t, really—go far enough to correct the toxic health problem that excessive exposure to light poses. Light should have a warning label, plain and simple.

By impeding healthy, abundant sleep and interfering with circadian rhythms, the consequences of unhealthful light exposure reach into nearly every aspect of life, including health, safety, productivity, and relationships.

Insufficient sleep and circadian rhythm dysfunction are linked to:

The epidemic of light pollution

While these ever-present devices—our smartphones and tablets—certainly contribute significantly to the problem, our unhealthful exposure to light existed before most of us had smartphones.

We live in an environment saturated with light. Think about all the sources of artificial light you encounter in a typical day. There’s the light in your home, the street lights that shine in through your bedroom window, the television and computer screens we log hours in front of after the sun sets. And yes, there are our phones, which too often reside on the bedside table.

In today’s world, darkness—essential for sound, plentiful, high-quality sleep—must be sought out, and is often difficult to achieve. Darkness triggers critical physiological changes that pave the way for sleep, including the release of melatonin, a hormone that regulates circadian rhythms and enables normal sleep-wake patterns. Exposure to light in the evening hours can significantly delay the release of melatonin and shorten the length of time the body produces melatonin. Both of these changes disrupt normal circadian function and sleep. It’s not only light from smartphones or other devices held at close range to the face and body that have this negative impact. Research shows that typical room lighting in the hours before bedtime exerts a high degree of disruption to melatonin release and duration.

Blue light, as a growing body of research demonstrates, is an especially aggressive disruptor of melatonin, circadian rhythms, and sleep. Studies indicate that blue light may be twice as potent a melatonin-suppressor as other light wavelengths. Efforts to improve energy efficiency have increased our exposure to blue light. That’s because blue light is emitted in higher concentrations in many energy efficient light sources, including LED and other energy-efficient lighting and LCD screens for digital and electronic devices.

To truly address the health problems that result from excessive light exposure will require a comprehensive environmental solution. Personally, I use lighting products that filter blue light so that light is not a factor for me or my family in the evenings. These types of products, in conjunction with new technologies like the one Apple is going to deploy, are empowering steps that enable us to create healthier environments for ourselves and our families.

What are the risks?

Where to begin

Light pollution and its negative effects to human health and safety are an important public health issue, one that continues to be overlooked. The harmful effects of excessive and poorly timed light exposure need systemic investigation and attention. At the same time, we don’t need major policy breakthroughs to begin to make positive changes in our own lives. We can all pay more attention to how we use light, particularly the ways and degrees to which we extend daylight artificially in the evenings or very early mornings. We can use products that address this issue in our homes and places of employment.

Handheld devices like smartphones are one of several considerations, and Apple is taking an appropriate initial step with Night Shift. But we all need—individually and collectively—to think bigger, broader, and much more about darkness if we’re going to effectively address the health threats of persistent and excessive light exposure. Light is medicine, and we need to understand and respect it.

Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™



Examining the effects of mobile phones on kids and teens


Is sleep technology making good on its promise to improve sleep?


Details from the new frontier of sleep

Photo credit: technoevangelist via / CC BY

Photo credit: technoevangelist via / CC BY

Do you use sleep technology to help your nightly rest? 

We talk a lot about the threats that technology poses to healthy sleep—the hazards of nighttime exposure to artificial light, the sleep-stealing impact of constant stimulation and engagement. But technology also has the capacity to change sleep for the better. New sleep technologies have flooded the marketplace in recent years. How are they working?

Learning about sleep tech

The National Sleep Foundation and the Consumer Electronics Association recently teamed up to learn more about sleep technology: who is using sleep tech devices, what’s motivating them, how sleep technology is changing sleep and other health metrics. Their survey included 1,029 U.S. adults. Their inquiry posed a range of questions about how often sleep technology is being used, what users believe it is—or isn’t—doing to help their sleep and their overall health.

The sleep technology currently available to consumers fall into some broad basic categories:

  • Multipurpose or sleep-only: A number of sleep technology options are in fact multipurpose, measuring activity levels, food intake and fitness in addition to sleep, while others are devoted exclusively to sleep.
  • Wearable or non-wearable: Some sleep technology involves wearable devices (think FitBit and Apple Watch, among others), while others require no equipment on the body to track sleep and provide other sleep assistance.
  • Tracking only, or “active” tech: Some sleep tech is completely devoted to tracking and analyzing sleep data, while other options offer sleep guidance and additional features (music, meditation) that are intended to directly influence sleep, along with–or instead of–tracking.

Sleep-tech basics

How common is sleep technology in people’s lives today? The number might surprise you. Of the adults surveyed by the NSF and CEA, 22% reported using some form of sleep technology. A large share of those users—38 %–report using a wearable fitness and health tracker that also tracks sleep. Smartphone apps are the next most commonly used form of sleep technology.

Not everybody who owns sleep technology is actually using it consistently, however. Of those 22% who own a sleep tech device or app, less than 10% are using their sleep tech regularly. A significant share of people who own sleep tech don’t feel they have a grasp on the technology: 23% of users say they don’t know how their devices can be used to help improve sleep.

Who’s using sleep tech? 

Not surprisingly, many of the users of today’s sleep tech products are young, health conscious, and tech savvy. Almost three-quarters of sleep tech users are under age 45. Among sleep tech users who use wearable technology, that number rises to 81%.

  • Sleep tech users are more likely than non-users to be single or never married than non-users
  • People using sleep technology products are more likely to be living in larger households than non-users. And 47% of sleep tech users have children under the age of 18.

The survey found that people who are using sleep technology consider themselves motivated to work on their physical and emotional health:

  • 70% say they are actively working to manage their mental health
  • 68% report eating healthfully most of the time
  • More than half are trying to lose weight

More than half report getting what they consider sufficient exercise every week.

Consistent, high quality sleep is critical to mental and physical wellness. Sleep helps to avoid and alleviate depression and anxiety, it helps keep weight on track and supports healthy eating choices, and makes exercise routines easier to maintain.

Gender, generation gaps

Men are more likely than women to be using sleep technology these days—57% of sleep tech users are men, according to the study. Men are especially likely to be using wearable sleep tech devices.

There is also a pretty significant generational gap among current sleep tech users—71% of them are under age 45. Men and women ages 25-34 make up the greatest share of sleep tech users—nearly one third of people using sleep tech fall into this age range.

Tech savvy, sleep soundly? 

The use of technology to improve sleep is part of a broader wave of comfort, interest and engagement with technology. Most of the people currently using sleep tech are “early adopters,” people who are eager and motivated to hop on board with new technology of all kinds. Among current sleep tech users, 78% fall into this early-adopter category.

Ease and overall engagement with technology is also a factor in how people are learning about sleep technology products and what they promise to do for sleep. Nearly half of sleep tech users—46%–report getting information about sleep tech from online reviews, compared to 32% of people who don’t currently use the technology. For those non-users, information gathered from physicians and other health-care professionals is the most popular—and most trusted—resource.

Luxury, not a necessity

What are the barriers to using sleep technology? Awareness is one. Twenty-nine percent of people reported not being at all aware of sleep technology. Even among people who own some form of sleep tech, 25% report being not very familiar with the technology.

Cost is another barrier. Among non-users of sleep technology, nearly half report that the technology is too expensive.

Many people who don’t currently use sleep tech say they simply don’t have a sleep problem that warrants the help—40% of non-users say this is the case. Interestingly, that number drops to only 10% among non-users who are sleeping less than 6 hours a night.

Sleeping in comfort (with technology)

Comfort is a key issue for both users and non-users of sleep technology—it is among the most important factors in considering whether to use sleep tech. Reliability and price are as important as comfort to respondents. Usability and durability are also ranked highly as attributes, as are the accuracy of tracking and the ability to convert sleep assistance into real-life improvements to sleep.

Many people care about the location of the device during sleep—do they have to wear something while sleeping? Is it necessary to have a monitor or a smartphone at the bedside to take advantage of high-tech sleep help?

These are excellent questions—for all the potential good that sleep technology may do, it can be undermined if the presence of devices is at all disruptive to sleep.

Technology is often regarded as exclusively undermining to sleep, intruding into our lives at all times of day and night and compromising healthy rest.  But the reality is more complicated than that.  While there’s little question that technological devices used at the wrong times can interfere with sleep, there is also great potential benefit for sleep in technology.  Tools that raise awareness about sleep and deliver substantive information and guidance to people struggling with sleep issues stand to have a powerful impact.

Next, we’ll talk a look at the health and sleep challenges that are motivating people to use sleep technology, and how effectively these technologies are—or aren’t—changing sleep habits and patterns.


Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™




7 Ways Sleep Powers Athletic Performance

10-23-15 Sleep Powers Athetic Performance - Football Player

It’s football season, and with that comes renewed interest in the effects of sleep on athletic performance. I’ve seen a number of articles referencing the contribution that sleep makes to on-field performance, including a recent piece in the Wall Street Journal, which details the growing interest among college football coaching staff in leveraging sleep for their players’ and teams’ advantage.

Coaches at many top universities are digging into the science of sleep, and what it reveals about sleep’s power to boost athletic performance. Several college football programs are taking new steps to ensure their players are getting enough sleep. Some are using sleep tracking to monitor the quantity and quality of players’ sleep, others are hiring sleep coaches to help players establish and maintain healthy sleep routines throughout the season. One coach even took up residence in players’ dorm during training camp to ensure players were getting to bed on schedule.

Sleep’s a smart play

Devoting attention to sleep is a smart strategy and a wise investment for athletes and teams. Athletes face more widespread and greater threats to healthy sleep than ever before, coming not only from the rigors of their schedules, but also from sleep-stealing use of technology.

Technology used in the wrong ways at the wrong times can pose hazards to health and to sleep, for athletes and non-athletes. The nighttime use of smartphones, tablets, and other devices emit sleep-disrupting light that suppresses melatonin, throws off circadian rhythms, and delays the onset of sleep. The result? More daytime fatigue, and less robust performance on and off the field. Young people—including college, elite, and professional athletes—are more likely to be using technology, and more likely to have their sleep disrupted as a result.

Sleep powers performance

Scientific research has long pointed to the performance enhancing powers of sleep. In the world of athletics, every bit of performance—both mental and physical—is immensely valuable. From speed and reaction time to decision-making and recovery, both sleep quality and sleep quantity can make athletes stronger, quicker, smarter, and more agile. Take a look at some of the most important ways sleep influences athletic performance:

1. Energy. It’s a given that athletes must marshal tremendous energy to sustain themselves practices and competition.  Lack of sufficient high-quality sleep limits and decreases energy in a number of ways. Poor sleep:

  • Decreases glycogen storage. Glycogen is the body’s stored fuel. When the tank is low, athletes can’t function optimally, mentally or physically. In particular, the loss of deep sleep (stages 3 and 4) diminishes glycogen levels.
  • Reduces testosterone. Testosterone enhances physical strength in both men and women. Testosterone strengthens muscles and bones, and promotes lean body mass. Testosterone levels diminish as a result of insufficient sleep, particularly REM sleep.
  • Lowers HGH. This hormone in its natural state contributes to the restoration, repair and healthy growth of cells and tissues throughout the body. Sleep is an important time for the HGH-led restoration and renewal. This important hormone is released at higher levels during sleep, particularly during the early phases of deep, or slow-wave, sleep. Circadian rhythms influence HGH levels. Studies show that HGH decreases when circadian cycles are disrupted.
  • Alters metabolism. Sleep helps to regulate metabolism, energy expenditure, and appetite. The balance of these factors is critical for athletes. Poor sleep upends that balance. When sleep deprived, appetite increases as toes the tendency to eat foods higher in sugar, fat, and carbohydrate. In a sleep-deprived state, the body adapts to increase energy consumption and decrease energy expenditure.
  • Diminishes muscle memory. Sleep is critical to motor skill development and learning, as well as to muscle memory. Research has pinpointed a neurological process that occurs during sleep in which the brain processes and organizes motor learning. Some significant portion of this sleeping brain activity occurs in the supplementary motor area, a region of the brain that enables complex movement and coordination.
  • Inflammation. Any athlete knows, inflammation equals pain, stiffness, reduced mobility and flexibility. Sleep plays an important role in managing inflammation. Sleep deprivation diminishes anti-inflammatory chemicals in the body, while at the same time increasing pro-inflammatory chemicals.

2. Reaction time. There’s a substantial body of research showing the effect sleep has on reaction time. Recent research suggests that reaction time may as much as triple as a consequence of sleep deprivation. Studies of college, elite, and professional athletes across a range of sports show sleep deprivation slows reaction time considerably.

3. Visual tracking. Research indicates that insufficient sleep impairs visual tracking skills. From hand-eye coordination to predicting trajectories, visual tracking skills are critical to gaining a competitive edge in sport.

4. Accuracy. Accuracy in physical, motor, and cognitive tasks is compromised by sleep deprivation, according to research. Diminished accuracy from insufficient sleep is on par with the effects of alcohol intoxication. That’s right—sleep deprivation is equivalent to drunkenness in its impairment of accuracy and other cognitive and motor functions. There’s also a direct correlation between hand-eye coordination and sleep.

5. Decision making. Assessing risks, making swift, complex decisions and on-the-spot judgment calls is part of the athlete’s challenge—and the ability to do so is key to athletic success. Numerous studies have demonstrated the negative effects of poor sleep on judgment and decision-making. Sleep deprived, we’re more likely to take unnecessary or ill-advised risks, despite being aware that those risks are present.

6. Memory. The brain is at work throughout all the stages of sleep to process, store, and secure memory. Sleep is a critical time for the brain to secure recently acquired information as memory, and to integrate that new learning with past experiences.

Athletes’ cognitive prowess is as important to their success as their physical excellence. Fascinating research shows how the brains of athletes are constantly making new neural connections, integrating information, relying on memory of previous experiences to make decisions and predictions swiftly and under pressure. Poor sleep undermines these important processes, impairing full memory function, and interfering with learning, storage and recall.

7. Recovery. Mental and physical recovery is essential athletes’ sustained performance—through the daily regimen of training, over a season of competition, and throughout the life of an athletic career. Sleep is essential to athletes’ recovery. Sleep deprivation and poor sleep quality both affect the restorative, recovery-based functions of sleep. So, too, does the disruption to circadian function that comes from irregular sleep habits, jet lag, and other sleep hazards that athletes commonly face.

Sleep also has a powerful influence over pain. Poor sleep slows healing. It also increases sensitivity to pain, lowering pain thresholds and elevating perceptions of pain. Sleeping well eases pain, and increases pain tolerance. Sleep also confers powerful rejuvenation and restoration of cognitive and physical skills and abilities.

The frontier of sleep as a tool and resource for athletes at all levels is an exciting one.

Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™


New details about how melatonin triggers sleep


Melatonin molecule

Though widely known as the “sleep hormone,” melatonin’s exact role in sleep is far from fully understood. We know of many links between melatonin and sleep: the hormone’s levels rise at night and fall during the day, regulated by the same circadian rhythms that help govern sleep. Disruptions in melatonin levels go hand in hand with sleep problems. But how, exactly does melatonin influence sleep, and our sleep and wake cycles? That, we do not yet really understand. Scientists at Caltech sought to find out more about melatonin’s precise role in sleep, and recently shared their results. Their findings shed some new light on how important melatonin is to sleep, and how it may function to bring sleep about.

To explore in detail the effects of melatonin on sleep, the researchers investigated the sleep-related functions of melatonin in zebrafish larvae. These tiny organisms have a circadian cycle similar to humans. They are awake during daylight hours, and sleep at night, during which time melatonin levels are at their highest. Researchers compared the sleep-wake patterns of normal zebrafish larvae to zebrafish larvae that were unable to produce melatonin, due to a gene mutation. The melatonin-deficient fish larvae slept significantly less than their melatonin-making counterparts, about half as long. The fish larvae without melatonin also took twice as long to fall asleep.

Researchers went a step further, and temporarily prevented the normal zebrafish larvae from making melatonin, by impairing cells in their pineal gland. (The pineal gland is also where melatonin is produced in humans.) Without the ability to generate melatonin, the zebrafish larvae displayed drastic changes to their sleep patterns. They began sleeping the same reduced amount as the genetically-mutated fish larvae, about half as much as they had slept when they were able to make melatonin. When researchers stopped preventing the fish larvae from making melatonin and they began to produce it again naturally, their sleep returned to its normal levels.

These results strongly suggest there is a direct role for melatonin in both falling asleep and in sleeping for a normal, healthy duration throughout the night.

The researchers also looked into how melatonin functioned in relation to the zebrafish larvae’s circadian clocks and their sleep-wake cycles. They first exposed both the normal zebrafish larvae and the genetically-mutated zebrafish larvae to a regular pattern of day and night—14 hours of light and 10 hours of darkness. This established the larvae with circadian clocks that operated in sync with the light and darkness. Then they moved both types of fish larvae to an environment of complete darkness. The fish that produced melatonin naturally maintained their normal circadian cycle of sleep and wakefulness, even in the absence of routine light exposure.

But the genetically-mutated zebrafish, which were incapable of producing any melatonin, lost all circadian pattern or rhythmicity to their sleep. Without melatonin, the fish larvae could not maintain circadian cycles of sleep and wakefulness. This was a surprise to researchers, and strongly suggests that melatonin is not just useful and helpful to circadian sleep-wake cycles, but essential to them.

Working with this understanding, that melatonin is required for circadian sleep cycles to function, researchers next sought to learn how melatonin goes about exerting this regulatory influence. They investigated the relationship between melatonin and adenosine, a neurotransmitter that in humans is thought to play an important part in the body’s homeostatic sleep system—our internal drive to sleep. In humans, adenosine levels rise in the brain throughout the day. This build-up of adenosine is associated with increasing feelings of tiredness and need for sleep. Adenosine levels decrease during sleep.

Researchers gave both normal zebrafish larvae and the melatonin-deficient larvae doses of a drug that stimulated adenosine. The two groups of fish reacted in very different ways. The adenosine had no effect on the normal zebrafish larvae. But among the melatonin-deficient fish larvae, researchers observed significant changes to their sleep. The genetically-mutated fish larvae began sleeping normally, in patterns like the fish that were able to produce melatonin.

This phase of their experiment suggests that one function of melatonin may be to help trigger the adenosine build up in the brain that in turn leads to feeling the need for sleep.

These findings also suggest that melatonin may be a bridge between the two powerful systems that govern sleep: the circadian system and the homeostatic sleep system.  We know these two systems both exert influence over sleep, and together create our basic 24-hour cycle of a long, consolidated period of sleep followed by an extended period of wakefulness. But science has yet to establish or uncover a direct, concrete link between these two systems. This research offers a lot of new detail about how melatonin actually may work on behalf of sleep, as well as the first evidence of a direct connection between our two sleep systems.

Next, we’ll examine recent scientific breakthroughs in understanding how melatonin may influence health and disease, and new therapeutic possibilities for melatonin.

Sweet Dreams,


Michael J. Breus, PhD

The Sleep Doctor™


New insights about ‘the darkness hormone,’ melatonin

Photo credit: radiant guy via / CC BY-SA

Photo credit: radiant guy via / CC BY-SA

Melatonin is central to our sleep and to our cycles of rest and activity. As much as we’ve learned about melatonin and its importance to sleep, there’s a great deal we still don’t yet know about the hormone’s biological functions and purpose. In the past few years, there have been some important breakthroughs in our understanding of how melatonin affects the body’s sleep-wake cycles, and how it may influence health and disease as well as sleep. We’ve also seen some discoveries about what may be melatonin’s possible role in the evolution the sleep itself.

Melatonin is a biologically ancient molecule, known to have existed in some of the earliest and most primitive living organisms. Recent research about melatonin has provided us with some fascinating new insights to the possible evolutionary beginnings of sleep. Scientists at the European Molecular Biology Laboratory in Heidelberg, Germany investigated how melatonin works in a form of marine zooplankton, a tiny, invertebrate ocean worm. The scientists’ discoveries may shed new light on the earliest biological origins of sleep.

Researchers studied marine zooplankton in their larval stage. These larvae have a regular, distinct day-and-night pattern of activity that unfolds in their natural ocean environment. As the sun sets, the larvae swim toward the surface of the water to feed under the cover of darkness. As the sun rises, they drop back to the ocean’s lower depths, where they remain—protected from predators and shielded from the sun’s UV rays—until the sun begins to go down and they start their upward move again. Scientists regard these cyclical patterns among zooplankton larvae as a possible link to an evolutionary ancient version of circadian rhythms, which exist not only in humans but also in nearly all animals and other living organisms.

Scientists wanted to see what role melatonin might play in the cyclical, night-day activity of the tiny larvae. Based on earlier research, scientists had already identified cells in the larvae that were sensitive to light and showed some basic similarities with the light-sensitive cells in the human brain that trigger melatonin production. Researchers investigated genetic make-up and activity of these light-sensitive cells, looking for evidence of melatonin and its possible relationship to the night-day routines of the larvae.

Researchers found that the zooplankton generated melatonin at night, and ceased melatonin production during the day. They also found that the nightly rise and fall of melatonin levels in the larvae was directly involved in helping the tiny organisms move up and down in the water. They even found that the larvae experienced their own version of circadian rhythm disruption, or jet lag—deprived of exposure to light, the larvae continued to produce the melatonin that regulated their movement in water according to their night-day cycle.

The researchers theorize that what they observed in the larvae may be a biologically ancient, primitive version of a sleep-wake cycle, one that traces back hundreds of millions of years. It’s an intriguing and compelling scenario about how our own sleep cycles may have originated.

In other research that suggests the deep evolutionary role of melatonin to sleep-wake cycles, the hormone’s fluctuating levels have also been linked—for the first time– to the lunar cycle. Researchers at Switzerland’s University of Basel have documented the first evidence that our sleep-wake cycles are influenced by the shifting phases of the moon.  The scientists didn’t set out to study the lunar influence over sleep. They used data from a previously completed study on circadian rhythms and the body’s internal, homeostatic sleep drive. Their study data included detailed sleep information about 33 healthy men and women, ages 20-74, who spent multiple stints sleeping in a laboratory setting that monitored and measured sleep and also controlled exposure to light, including moonlight and artificial light at night.

Researchers found that melatonin levels—along with several other important markers of sleep—shifted significantly along with the changes to the moon. At the time of the full moon, nighttime melatonin levels were at their lowest, having fallen steadily in the several days leading up to the full moon. After the full moon passed, nighttime melatonin levels rose, before beginning to drop again after passing the halfway mark toward the next full moon. In addition to the changes in melatonin, researchers also found that people slept less overall, spent less time in deep sleep, and took longer to fall asleep in the same corresponding pattern to the full moon. These findings surprised researchers and other scientists—we’ve never before seen reliable scientific evidence of a connection between sleep and the lunar cycle in humans. Their research—preliminary to be sure—suggests that our sleep-wake cycles may not only operate under the influence of the 24-hour circadian cycle of daylight and darkness, but under the effects of the roughly 29-day lunar cycle as well.

Next, we’ll take a look at research that explores in groundbreaking new detail ways melatonin may influence the body’s circadian clock.


Sweet Dreams,


Michael J. Breus, PhD

The Sleep Doctor™


Hot enough for you? Sweating at night undermines sleep

Photo credit: Mr.TinDC via / CC BY-ND

Photo credit: Mr.TinDC via / CC BY-ND

Do you ever experience night sweats? It’s an uncomfortable feeling, to wake from sleep drenched in sweat, your pajamas and sheets damp and clammy. Sweating at night can be highly disruptive to sleep, keeping you from falling asleep and rousing you out of your sleep repeatedly throughout the night.

Sometimes, of course, we sweat at night because it’s hot outside and in our bedrooms. These days of high summer can bring about plenty of sweaty nights and restless, less-than-refreshing sleep. Warm weather and warm sleep environments are the most common reason for occasional nighttime sweating—and they highlight the importance of controlling temperature during sleep. Sweating is the body’s defense against overheating. A cool bedroom is the best temperature environment for sleep, year round. In the warmer months, that means most of us will need to put some work into keeping bedrooms cool.

How cool? The right temperature really is the temperature at which you can fall asleep comfortably and stay asleep without waking—or sweating. For most people, that’s a temperature in the low to mid-60s Fahrenheit. Fans, air-conditioning, opening the windows at night to let a cooler breeze through the house are all warm-weather practices that can help your sleep. And don’t forget to close curtains or draw blinds in order to keep the sun blocked, and your bedroom cooler, during the day. Wearing light bedclothes—or no clothes at all—can also help keep you cool, and avoid sweating and heat-related discomfort at night. Breathable fabrics like cotton and linen are the best choices for clothing and bedding, when you’re looking to stay cool.

But sweltering temperatures aren’t the only reason people experience night sweats. Sweating during sleep has a wide range of causes. Several different types of medication can lead to night sweats. Anti-depressants, steroids, pain medication, hormones, and medication for diabetes are all types of drugs that have night sweats as a side effect. Often, night sweats are a consequence of another condition or ailment. Here are some of the more common conditions that are linked to nighttime sweating:

Menopause. Night sweats are a frequent symptom for women in menopause, and sometimes for women in perimenopause. Women in menopause and perimenopause often experience sleep troubles, including night sweats, as a result of fluctuating hormone levels. The quality of sleep—and how well you feel during the day—can be deeply affected by night sweats and other menopause-related sleep disruptions. These sleep disruptions last for an average of slightly more than 7 years, according to new research. There are treatment options for women experiencing night sweats, including cognitive-behavior therapy (CBT), which research indicates can help alleviate night sweats and other menopause symptoms.

Other hormonal changes and imbalances. People with several different types of hormonal imbalances may sweat at night during sleep. Hormone dysfunction associated with diabetes and with thyroid disorders both can cause night sweats. The hormonal changes of puberty can also lead to night sweats—as can the hormonal fluctuations of pregnancy.

Obstructive sleep apnea. It’s a lesser-known symptom than snoring and daytime fatigue, but night sweats can be a consequence of OSA.

Obesity. Being overweight and obese can make night sweats more likely. Carrying too much weight can pose an array of other problems for sleep, including increasing risks for sleep disorders such as obstructive sleep apnea.

GERD. Gastroesophogeal reflux disease—most commonly known as acid reflux or heartburn—can bring about uncomfortable night sweats. GERD is problem for sleep in general. People with nighttime heartburn are likely to experience disrupted sleep, including trouble falling asleep and staying asleep.

Anxiety. Stress and mood problems, including anxiety, may cause sweating at night that makes sleep uncomfortable. Anxiety and other mood disorders can be deeply disruptive to sleep, and stress is among the most common causes of sleep trouble.

Night sweats can also be signs of other medical issues, including infection, adrenal dysfunction and cancer. With such a broad range of possible causes for night sweating, it’s important to speak with your physician if you observe any changes to the typical ways your body sweats at night—if you begin to sweat more frequently, or if your sweating increases in intensity.

There are ways other than keeping your bedroom cool and wearing the right clothes that can help diminish nighttime sweating. They also happen to be strategies that are good for sleep in general, including:

  • Exercising regularly
  • Staying hydrated during the day
  • Avoiding caffeine, alcohol, and heavy meals—especially spicy foods—within 3 hours of bedtime.
  • Taking some time to relax and unwind before bed, using simple breathing or meditation exercises

Don’t suffer at night because of night sweats. This soggy, uncomfortable experience will interfere with how much sleep you get, and how well you sleep. Make sure you’re sleeping in the right environment—cool but not cold, and not overheating in too much clothing or bedding. And discuss with your physician any questions or concerns you have about nighttime sweating.

Sweet Dreams,

Michael J. Breus, PhD

Michael J. Breus, PhD

The Sleep Doctor™



Digging into memory—and its relationship to sleep

Photo credit: Marc Wilson-Blackburn via / CC BY

Photo credit: Marc Wilson-Blackburn via / CC BY

We’ve all had the experience of having our memory fail us, whether it’s forgetting a name, struggling to remember what you did the day before, or wandering in search of a pair of keys. Before you ascribe that fuzzy memory to a “senior moment,” or to the frenetic pace of daily life, try putting your head to the pillow for a good night’s rest. Sleep—how much you get, and how well you sleep—can have a powerful effect over memory.

When we talk about memory and its relationship to sleep, we’re talking about the intersection of two complicated and dynamic physiological processes—processes that science is still working to understand. Broadly speaking, we can talk about the memory process as having three distinct phases:

Acquisition: taking in new information

Consolidation: storing information that’s been acquired

Recall: retrieving memory from storage

Sleep can play a role in helping—or hindering—each of these aspects of memory. Sleeping well, and avoiding sleep deprivation, can make a real difference in your ability to take in new information—essentially, to learn. If you’ve ever tried to study for a test or complete a work project while short on sleep, you’ve experienced the obstacles that sleep deprivation can have on memory acquisition. Even a very short period of sleep deprivation can diminish your capacity to form new memories in everyday learning.

One recent study illustrates the possible benefit of sleep to skill learning and the formation of new memories. Scientists studying the neural activity of mice found that a period of sleep immediately after learning a new skill encouraged the growth of synapses in the brain that were specifically related to that new learning. Tested on performance after periods of 1 and 5 days, mice that slept after the initial learning performed twice as well on the newly learned task than mice that had not slept.

Sleep is also important to your ability to recall memories you’ve already made. Research indicates that recall of both short-term working memory as well as long-term memory of different forms are impaired by lack of sleep. A sleep-deprived brain is less effective at memory retrieval, while staying well rested can help protect and improve this “remembering” phase of memory.

While both memory acquisition and memory recall are influenced by sleep, it is the middle phase of the memory process—consolidation—that actually occurs during sleep itself. Memory consolidation takes new knowledge you’ve acquired and stabilizes that information, preserving it for future recall and helping to protect it from disruption or degradation over time. Memory consolidation that takes place during sleep not only secures memory for future retrieval, but also appears to free up the learning centers of the brain in preparation to take in new batches of information in the next waking day. Scientists are still discovering how memory consolidation works during sleep, but it’s believed that memory consolidation occurs during several different stages of sleep throughout a night’s rest. The slow brain wave oscillations and sleep spindles that are characteristic of deep sleep (also known as slow-wave sleep), appear to play a critical role in memory consolidation, particularly for forms of memory that involve the brain’s hippocampus. The relationship between REM sleep and memory is especially complicated, and still not well understood. But REM sleep, with its high levels of brain activity and dreaming, appears to also be important to the processing and consolidation of some types of memory.

The large and growing body of research devoted to the relationship between memory and sleep suggests that a routine of sleeping well can have a positive, protective effect on memory. Keep in mind that both the quantity and the quality of sleep are important to memory function. Here are some basic strategies that can help you sleep both more and better:

Establish a sleep routine. A consistent bed time—one that allows for 7-8 hours of nightly rest—is the foundation of a strong sleep routine, and can help you avoid the sleep deprivation that interferes with memory and other cognitive functions.

Be thoughtful about consumption. Avoiding stimulants such as caffeine and alcohol within several hours of bedtime can help improve sleep quantity and quality. Not only can these substances make it more difficult to sleep, they can disrupt normal sleep cycles, and may alter time spent in the stages of sleep that are most important to memory consolidation. Eating heavily in the evenings, and eating late at night, can also disturb sleep quality and lead to restless, interrupted sleep.

Ease your stress. Managing daily stress is also critical for healthy, high-quality sleep. Worry and anxiety are among the most common sources of poor and insufficient rest, leaving you with a tired body and tired mind at the beginning of the next day.

When you’re tempted to stay up late for the sake of being productive, in mind that you and your memory ultimately will be better served by getting a good night’s sleep. Well rested, you’re more likely to feel better, perform better, and to remember more.


Sweet Dreams,

Michael J. Breus, PhD

The Sleep Doctor™