Sleep is the foundation of our physical well-being. Simply not getting enough sleep can harm our physical health; it’s linked to an increased risk of heart disease, type 2 diabetes, obesity, and cancer. But sleep serves an emotional function as well. For example, people who don’t get enough sleep are less able to absorb positive experiences and are more likely to report feeling negative. Several theories link sleep to healthy functioning: restoration, learning and memory, and brain plasticity. But what might surprise you is the strong relationship between sleep and mental health. In this essay, we’ll explore sleep and mental health.
The deepest stage of sleep, known as slow-wave sleep, is deeply restorative; it’s a time when the brain and body can repair themselves from the stresses and demands of the day. For this reason, sleep professionals talk about slow-wave sleep as one of the cornerstones of mental wellness. Certain types of lifestyle changes can boost slow-wave sleep and sleep overall. Cutting back on caffeine and avoiding caffeine late in the day also helps. Managing stress throughout the day has two benefits: it helps you maintain an even keel during the day and night, but it also helps you avoid spikes of stress hormones near bedtime. This approach is more helpful than just banning technology alone. Since light impacts our circadian rhythms, having an evening indoor/outdoor approach can work to your advantage. The message is clear: to sleep better, you need to believe sleep is important. Though we don’t have good treatments for all the different kinds of mental disorders that involve sleep, cognitive behavioral therapy for insomnia has the most evidence to support it and will help you establish those healthy sleep beliefs.
Definition and Stages of Sleep
Sleep is a naturally recurring state characterized by drastically reduced environmental awareness and muscle activity. Tentatively, sleep can be broken down into rapid eye movement (REM) and an assortment of non-REM (NREM) stages, each characterized by unique physiological and psychological processes. The four stages of NREM sleep are progressive, increasing in depth, before one enters an initial period of lighter sleep. REM sleep is closely tied to mental processes and elicits an increase in heart rate, cerebral blood flow, glucose consumption, and cortical activity.
As far as defining sleep goes, it is a state of unconscious inactivity marked by time-locked changes in the nervous and endocrine systems. The electrical activity in one’s brain unnoticeably changes, passing through different stages of sleep ranging from light all the way to deep brainwave patterns that characterize one’s capacity to wake. Sleep can remain intricate, as seen in patients who presented under general anesthesia experiencing two non-REM cycles and four REM periods over a 65-minute period.
The stages of sleep—non-rapid eye movement (NREM) sleep is the progression from going to sleep to deep sleep. It consists of four sub-stages, in which dreams are infrequently reported. After reaching the pinnacle of the cycle, stage 4, NREM sleep begins its transition back toward stage This progression allows one to transition between NREM and REM sleep, where dreams are likely to be reported. During NREM sleep, one’s brain is largely recovering; blood flow decreases to brain tissues involved in memory and emotion, and beta-amyloid is cleared from the extracellular spaces during N3 sleep, potentially contributing to dementia many years later.
Historical Perspectives on Sleep
Sleep’s role in health and wellbeing has been a point of interest for many societies throughout history. Many ancient cultures held a link between rest and mental health, providing an accommodating posture to those in need. Old wives’ tales paint contrasting ideals; medieval Europeans believed that sleeping on a fresh grave could cure insanity, while the ancient Greeks taught parents to lay their children’s cradles south to assure deep slumber. In the past, each subsequent era began to acquire inexplicably new beliefs about sleep. In the U.S. between 1792 and 1910, as towns became well-lit with steam power and electric streetlamps, we slept more as a nation but enjoyed less efficient rest. At the dawn of modern scientific applications to sleep, it was found that the average American slept in two periods, twice a day: a first slumber before midnight, often interrupted, called “The Watch,” and “The Morning Nap” between 2-3 a.m. and dawn. Gradually, the Industrial Revolution ushered in new shifted workdays, for which scientists identified the real sleep ideal, “8 hours,” later in the 1950s, supported by a poll, for which the nation’s maximum time spent in slumber was on Saturday nights at 7 hours and 52 minutes. By the year 2000, a flat 73% of America were “stressed” and “tired,” and none adequately managed depression, panic, or fatigue; we re-entered a new time of slumber research and personal techniques to increase quality of life.
The Link Between Sleep and Mental Health
For decades, experts believed that poor mental health disrupted sleep because of racing, repetitive thoughts and anxiety. Now, numerous studies indicate that disrupted sleep can be a cause, rather than a symptom, of such disorders, playing a part in sustaining the mental health issues or making them worse. Sleep is known to be a bi-directional trait that can be altered in response to changes in mental activity; targeting sleep-related issues is therefore emerging as a lucrative strategy to treat conditions such as depression by reducing arousal, rather than challenging negative thoughts. When sleep is impaired, the neurotransmitters essential for managing mental distress are disrupted, causing an overactive system, which increases the likelihood of experiencing anxiety. Poor sleep is also shown to disrupt other neurotransmitters such as dopamine, which are involved in experiencing pleasure, possibly leading to feelings of depression. Studies focusing on sleep have illustrated the possible physical consequences of poor sleep, which include the shrinking of the prefrontal cortex, the part of the brain that supports effective decision-making, and excessive beta-amyloid accumulation, leading to cognitive decline or dementia. People who are unable to sleep are statistically more likely to show signs of cognitive decline one year later, including issues such as memory decline; difficulties thinking and expressing themselves; and executive dysfunction, a term that includes planning and problem-solving abilities, all of which can contribute to a reduced capacity to carry out everyday tasks independently. The stronger the link to sleep issues, the greater the decline across these types of cognition. Reduced slow-wave sleep has also been shown to predict which adults will develop dementia over a ten-year period. Finding quality treatments for sleep is no simple task. Given the complex link between sleep and psychological function, it is unreasonable to consider treating these illnesses without addressing sleep. Understanding the underlying psychological connections between sleep and mental health can provide cues for developing therapies targeting sleep to alleviate mental distress states. This also leads to a plea for the development of a more joined-up culture in medicine between those treating sleep and mental health issues. Major efforts to capitalize on the bidirectional relationship of sleep and mental health in the form of cognitive behavioral therapy for insomnia and depression show that by targeting sleep, it is possible to make a material difference to mental health.
Impact of Sleep on Cognitive Function
Sleep and Cognition You’re likely already aware that your sleep schedule can greatly influence your mood and energy levels. But did you know that sleep also interacts with your cognitive function, which includes things like attention, memory, and decision-making? Sleep promotes synaptic consolidation, which helps you learn more efficiently and improves your memory. Unfortunately, people who are sleep deprived often struggle with these activities due to reduced brain function. During a good night’s sleep, you do a lot of things that help your brain refine and store important information. When you are in deep or slow wave sleep, your brainwaves slow down, which is associated with increased memory consolidation. This means that whenever you try to learn something new or engage with content you’ve already learned, sleep can make you a better learner. Students who were allowed six hours or less of sleep per night during the entire duration of an educational course and participated in academic activities twenty hours a day showed progressive underperformance in academic activities. These same students showed progressive improvement in cognitive function, alertness, and mood after returning to a more typical eight-hour sleep schedule for just five nights. These kinds of findings signal that while you can stay up late to study for an exam or finish a project, you may actually be reducing your ability to learn and remember new information. Furthermore, when sleep-deprived students nap during the day, they show better cognitive performance the next day than they did after a day of complete sleep deprivation. While the nap isn’t as effective as their normal eight hours of sleep, it does improve their cognitive performance. This suggests that while a good night’s sleep is the best scenario, naps can provide temporary aid when you are sleep deprived. In addition to memory and learning, sleep also affects our ability to think critically and solve problems. This can be particularly harmful in the workplace or in school. For example, people who experience sleep difficulties are more likely to perform poorly in their job, struggle in their relationships, and get into more arguments. Similarly, poor or inadequate sleep can also lead to a higher chance of academic failure. The effect of sleep on cognitive function, learning, and memory has real implications for yourself and society, and improving the quality of your sleep can increase overall cognitive performance. Conclusion Sleep plays a significant role in the necessary neurochemical processes that help support cognitive functions during your wakeful life. Synaptic consolidation, which takes place during deep sleep, helps with learning and storing memories. Thus, individuals who get an adequate amount of sleep see lateralized gains in this learning and problem-solving ability, allowing them to be better learners and more productive in the later stages of life. Deep sleep is the pinnacle of the sleep world, but what if a lack of sleep is affecting your life cognitively? The next section explores how a lack of deep sleep can hit you where it hurts — your frontal lobes.
Common Sleep Disorders and Their Mental Health Implications
While sleep disorders might sound less serious than other forms of mental health issues, individuals who struggle to get adequate rest can experience a host of negative health problems. Some of the most common sleep disorders can be very disruptive to daily life and can lead to excessive anxiety or chronic health issues if left untreated. The consequences are too severe to ignore, as a good night’s rest should be a cornerstone of all mental health care.
Three sleep disorders are widely recognized for their implications on mental health. These include insomnia, sleep apnea, and restless legs syndrome. A significant portion of mental health symptoms can be traced back to sleep disturbances. Conversely, those with any type of mental health condition can be at higher risk of developing a sleep disorder, as the relationship is bidirectional across the board. Sleep disorders are widespread among many individuals but are not commonly diagnosed because they may not seek help or confide in their primary care provider about their rest habits. To further complicate the matter, sleep difficulties and mental health issues can worsen the severity of the other. For example, an individual with depression is five times more likely to report nonrestorative sleep issues and 21 times more likely to say that they struggle with excessive daytime sleepiness. These statistics illustrate the significance sleep, or lack thereof, plays in managing the symptoms of preexisting mental conditions. Since mental health is integral to this conversation, it should be treated with equal significance. It is also essential to diagnose them in their earliest stages to try to mitigate the effects that they have on mental health and well-being. When individuals notice that they are asking themselves, “What are the symptoms of sleep apnea, sleep insomnia, and restless legs syndrome?” it’s time to consider checking with their primary provider. Although some people may be sleeping, they may not actually be resting. The psychological impact of lack of sleep can be illustrated through case studies. For example, a case study where a 25-year-old graduate student was followed for a sudden and severe onset of insomnia that persisted over the span of a year. The student’s sleeplessness led to anxiety and mood disturbances, but without a specific cause.
Insomnia
Insomnia is one of the most commonly diagnosed sleep-related disorders. It is estimated that 30% of adults experience short-term symptoms, with 10% developing chronic difficulties falling or staying asleep. The condition is usually characterized by difficulty initiating or maintaining sleep, or early-morning awakenings that cause significant disruption to daily routines and emotional well-being. Acute insomnia is usually triggered by stress, other life events, or health issues and persists for less than a month. Beyond this, symptoms are attributed to latent psychiatric conditions, medical or neurological disorders, or the use of certain medications or substances. The prescribed and recreational use of alcohol and various other substances, such as caffeine and nicotine, can also have an effect on sleep onset and sleep maintenance.
Similar to other behaviorally defined disorders, insomnia is a complex condition that is influenced by multiple physiological and cognitive factors. These include low levels of melatonin or other chronobiological substances, hyperarousal or overactivation of the sympathetic nervous system, and quickly occurring sleep-state misperception (sleeping too short, believing to have slept less) or difficulty maintaining sleep (sleep-state misperception) rather than difficulties falling asleep. The condition is commonly comorbid with several additional or stand-alone disorders, including depression, anxiety disorders, bipolar disorder, and other psychiatric conditions. Data suggest that in patients with chronic major depression, psychosis, or schizophrenia, a significant percentage meet criteria for comorbid insomnia. Left untreated, the disorder tends to develop into a self-perpetuating and self-exacerbating condition that is difficult to reverse. Individuals living with predominantly maintenance insomnia, or sleep-maintenance issues, develop a conditioned response to their lack of sleep and bedtime-related anxiety that further hinders falling asleep and prolongs nighttime wakefulness.
Sleep Apnea
Sleep apnea, derived from the Greek word for absence of breathing, describes a severe sleep disorder that causes pauses in breathing during sleep. It can pose a serious risk to overall health. There are two different types of sleep apnea. Obstructive sleep apnea, often simply referred to as sleep apnea, is a condition in which the throat muscles relax and fail to keep the airways open. Central sleep apnea is a condition where the brain fails to signal these muscles appropriately. Sometimes, a combination of these two types, called treatment-emergent sleep apnea, is diagnosed if obstructive sleep apnea is successfully treated but central sleep apnea persists. Obstructive sleep apnea has the additional risk factor of obesity, as an increase in fat deposits in the neck can worsen the compromised airways. This condition is also associated with children, especially those with enlarged tonsils or adenoids.
If left untreated, sleep apnea can lead to an array of severe health problems. The persistent oxygen deprivation associated with sleep apnea can raise the risk of cardiovascular problems such as high blood pressure, chronic heart failure, arrhythmias, heart attacks, and strokes. Several metabolic disorders, most prominently obesity and type 2 diabetes, are also at a higher risk with untreated sleep apnea. This can contribute to complications during sleep apnea, where sleep is frequently interrupted. Additionally, the impaired breathing of sleep apnea can lead to cognitive issues and mood disturbances, culminating in a significantly worsened quality of life.
Sleep apnea is usually detected by performing special sleep studies at a sleep center, such as nocturnal polysomnography. Polysomnography records an array of variables during periods of sleep, highlighting, for instance, oxygen saturation in the blood, body movements, brain and muscular activities, and leg movements. Home sleep studies are also possible, usually involving a smaller set of data points such as pulse oximetry, body position, airflow, and snoring. Both children and adults can develop sleep apnea, but obesity can raise the likelihood of this condition. A positive family history is also a risk factor, and men are just about twice as likely as women to have sleep apnea. Sleep apnea normally worsens with age, the odds of developing the condition tripling between 30 and 60 years of age.
Treatment for sleep apnea is contingent on the severity and the type of sleep apnea diagnosed, and based meticulously on case definition. Minor cases of obstructive sleep apnea, for example, might be managed with lifestyle changes including oral appliance therapy or upper airway surgery. Untreated and mild cases may warrant just lifestyle changes. Reduced sleep apnea severity and risk factors are the goals of treating moderate cases with lifestyle changes and oral appliance therapy or surgery. Continuous positive airway pressure is the most common and soundly effective remedy to nearly all cases of obstructive sleep apnea as it offers the most efficient and instant symptomatic relief. After therapy initiation, regular follow-up is imperative in order to confirm adherence, attention, and care to ensure that sleep apnea’s risk factors are progressively reduced.
Strategies for Improving Sleep and Mental Health
There are many steps that can be taken to improve the quality of sleep, which in turn positively impacts both our mental health and resilience. One of the most robust findings in sleep science is that having a consistent bedtime and wake time is essential for quality sleep. Other practical strategies include reducing screen use in the hour or so before sleep. Sleep hygiene refers to the behavioral practices and environmental factors that are necessary for healthy sleep. A regular, relaxing routine around bedtime can be helpful, such as reading or taking a bath. The sleep environment also matters. For instance, a fairly cool, quiet room with a comfortable mattress and pillow is commonly suggested.
It is also important to consider lifestyle factors such as diet, exercise, and mental well-being. Factors that can disrupt sleep include eating or exercising too close to bedtime, or drinking too much caffeine or alcohol. In contrast, low to moderate exercise is generally advised for promoting better sleep. Mindfulness techniques can help some people manage anxiety or worry that disrupts sleep. In reality, many people are unable to fall asleep because they are unable to significantly resolve their sleep problems through the identification of predisposing, precipitating, or perpetuating factors. Accruing good quality sleep is highly important for maintaining the right balance of systems in our brain and body. Like many things in life, it is desirable to be much more proactive about seeking out information about what we can do to help improve our own quality of sleep. By tackling our sleep, we may find we are protecting ourselves from the development of a range of health issues – be those physical or mental in nature.
Sleep Hygiene Tips
A good night’s sleep affects all realms of our health. However, we often don’t allot the time necessary for our bodies and brains to fully recharge. The daily leisurely activities, busy work schedules, and accidental snooze button presses multiply those effects over time. The good news is, we can break that cycle of sleepless nights. To stress the point, cognitive-behavioral therapy for insomnia is an effective form of counseling. It teaches you how to improve sleep habits. This is part of a health care provider’s treatment plan for insomnia. If sleepless nights trouble you, the best way to decrease snoozing on the weekends and to quickly fix the sleep clock is to consult a trained sleep expert. For certain people, other types of therapy prove helpful.
• Set a routine. Go to bed and wake up at the same time daily. This helps your body establish a routine. When your alarm goes off at the same time every day, your body will start conforming to that alertness schedule. • Stick to a sleep schedule. Be consistent. It helps your physical body and brain to regulate your usual sleep schedule. This promotes sleep quality. • Create a relaxing bedtime routine. Take a warm bath, read a book, or listen to soothing music. Reduce exposure to gadgets and blue light from screens. • Design a cozy sleep environment. A warm, welcoming bedroom will help you relax. Exposure to light helps with sleep. You may use thick curtains, a dark shade, or a sleep mask if needed.
As we have explored in this essay, the relationship between sleep and mental health is one of profound interconnectedness. New understanding of the shared biological and mechanistic pathways that underlie sleep and mental health has shed light on years of reports that sleep disturbances both present before the onset of mental health problems and are associated with poorer treatment outcomes. This expanded white matter conduit begs a reevaluation of mental health. Dominant models treat the mind and body as separate entities, whereas increasing evidence suggests that they are always connected and that approaching mental and physical illnesses holistically will improve patient outcomes. We aim to see sleep influence today’s guidelines and tomorrow’s targets, innovate interventions, and reduce the negative impact on people. Given nearly a decade of evidence pointing to sleep as a critical arbiter of emotional, social, and behavioral well-being, we call for innovative interdisciplinary and multidisciplinary research focusing on sleep in adults with mental health difficulties. From clinical trials exploring mechanistic pathways between sleep and psychopathology to well-being and epidemiological studies supporting public health initiatives, sleep no longer deserves to be relegated to dreams and the topic of insomnia referrals. We urge both researchers and clinical researchers—across the spheres of psychiatry, general practice, psychology, and allied health—to go back to bed: the science of sleep is upon us. Sleep matters, but few remember. It is time to bring sleep into the light and to empower individuals. Our sleep, and our bodies and minds, are in our hands.
