Abstract and Keywords
Sleep is required for healthy and adaptive neurobehavioral and psychosocial functioning throughout the life course. Sleep is restorative, facilitates memory consolidation, improves immune function, and regulates emotional responses. Sleep deprivation, whether due to sleep disorders or other life conditions and transitions, is a significant risk factor for negative developmental outcomes at all stages in the life course. This article adheres to the biopsychosocial model to review current research describing the benefits of adequate sleep and ways in which insufficient sleep, as determined by developmental needs throughout the life course, can undercut healthy development. Particular attention is paid to social issues of relevance to social workers, with a closing discussion of policy and implications for future work within the field.
This article takes a life-course approach in describing research findings on sleep and adheres to the biopsychosocial model to address the benefits of sufficient sleep and ways in which insufficient sleep can undercut healthy development. Animal studies suggest that sleep is required for survival, a neurobiological imperative that affects almost all tissues in the body (NIH, 2013; NINDS, 2014). Recent advancements in neuroscience and genetics have begun to elucidate the biological underpinnings of the mechanisms in which adequate sleep contributes positively to domains such as cognitive, emotional, and physiological functioning, and the heavy toll that sleep deprivation takes on our biological systems such as immune and psychosocial functioning (Basner, Rao, Goel, & Dinges, 2013; Engle-Friedman, 2014; Mental Health Foundation, 2011; Kahn, Sheppes, & Sadeh, 2013; Sapolsky, 2004; NINDS, 2014; Tempaku, Mazzotti, & Tufik, 2015). Understanding sleep within a biopsychosocial framework is particularly relevant for social workers because for many populations that social workers serve, sleep is interrupted or unavailable on a regular basis, while for other clients, impairments with sleep may be comorbid with related conditions or disorders, possibly worsening presenting symptoms.
The organization of this article is as follows. First, sleep is introduced as a dynamic activity, with information about stages of sleep and circadian rhythms. Next, insufficient sleep is presented as a public health concern, both national (within the United States) and global (across the world). Here, risks to health associated with insufficient sleep and the benefits of sufficient sleep are briefly described, and recommendations to promote sleep hygiene follow. Next, a section on sleep disorders, including classifications based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) (American Psychiatric Association & American Psychiatric Association DSM-5 Task Force, 2013) and the International Classification of Diseases, Tenth Edition (ICD-10) (WHO, 2015), are reviewed. Following this, empirical findings from sleep studies within many fields (from neuroscience to education) are introduced by stage of development, beginning first with pregnancy and ending with late adulthood.
Although this review of findings by developmental stage is not exhaustive, it is intended to illustrate ways in which sufficient sleep is beneficial or insufficient sleep can pose a risk, with special attention paid to particular environments and relationships that may either contribute to or provide insulation from such risk processes. The article closes with a discussion of sleep and public policy and includes recommendations from the literature covering many stages of the life course introduced earlier. Given the tremendous implications that sleep has for optimal biopsychosocial functioning throughout the life course, a succinct and timely review of findings and implications is relevant for social workers within all contexts in the field, including but not limited to those engaged in proximal work in schools and hospitals and those active with policy work in treatment, healthcare, and psychoeducation.
Sleep Stages and Cycles
According to the National Institutes of Health, sleep was misperceived until the 1950s as a passive activity, but today we recognize sleep to be a dynamic activity corresponding to our daily functioning and physical and mental health (NINDS, 2014). Neurotransmitters (chemical communicators passed between brain cells called neurons) control whether we are asleep or awake. It is the neurons in the brainstem that send out neurotransmitters, such as serotonin and norepinephrine, that signal the brain to be active when we are awake, while other neurons send out messages for sleep by essentially turning off the signals maintaining wakefulness (NINDS, 2014). Extant work suggests that adenosine, a neuromodulator (i.e., a neurotransmitter that sends chemical signals to many diffuse regions in the brain) builds up as we accumulate sleep debt (meaning the longer we are awake), which can be measured in rising levels in our blood during periods of wakefulness and that leads to the feeling of drowsiness until we begin to address the debt level via sleep (Brown, Basheer, McKenna, Strecker, & McCarley, 2012).
There are five stages of sleep, progressing in succession through stages 1, 2, 3, 4, and rapid eye movement (REM) sleep, with a complete sleep cycle taking about 90 to 110 minutes, which allows for about four or five cycles throughout one period of sleep (Purves, 2008; Sapolsky, 2004; NINDS, 2014). The research summarized next by the National Institute of Neurological Disorders and Stroke (NINDS) (2014) suggests different functions and experiences based on each sleep stage. For example, whereas stage 1 sleep is very light and we can be stirred to wake easily, stage 2 sleep shows the cessation of eye movement and the slowing of brain waves intermixed with occasional rapid bursts called sleep spindles. Stage 3 sleep shows even slower brain waves along with some faster waves called delta waves, which are waves that comprise stage 4 sleep almost in its entirety. Together, sleep stages 3 and 4 are referred to as “deep sleep,” and it is during these stages that a person can feel particularly disoriented if awakened.
During deep sleep, children may experience night terrors or engage in bedwetting or sleepwalking. During REM sleep, which appears between 70 to 90 minutes after we fall asleep, breathing is irregular, heart rate increases, blood pressure rises, and dreaming takes place. If awakened during REM sleep, some individuals report unusual and bizarre dreams, a process perhaps explained in part because during this stage, the subcortical limbic system (emotions) of the brain, particularly the amygdala, takes control from the frontal cortex, which is responsible for executive functioning such as planning and decision-making (Bronson & Merryman, 2009; Sapolsky, 2004). Initial cycles of sleep contain more deep sleep and less REM, whereas later in sleep, this pattern is reversed. During REM, we lose the ability to thermoregulate and therefore environments that are very cold or hot can disrupt the sleep cycle. Developmental differences are seen among time spent in each of these stages. According to NINDS (2014), adults spend the least overall percentage of time in REM sleep (about 20%), whereas infants spend about half their time in REM sleep, a stage that has been found to activate brain regions involved in learning, which may serve to explain why the young spend so much time in that sleep stage compared to older groups. Adults spend the majority of their sleep time in stage 2 (about 50%), and the remainder distributed among stages 1, 3, and 4 (NINDS, 2014). The implications for the varying distribution of time spent in each stage, as well as particular populations at risk for impaired sleep by stage, will be explored in more detail in the upcoming individual sections of this article covering stages of development by age. Because sleep and wakefulness are signaled by neurotransmitters, anything that can influence these chemical signalers (such as caffeine) can affect sleep and induce insomnia (NINDS, 2014). According to NINDS (2014), many antidepressant medications can reduce REM sleep, and those who are heavy smokers tend to sleep more lightly and have reduced time in REM sleep, as nicotine withdrawal can wake them at 3–4 hours. Research summarized by NINDS (2014) also suggests that alcohol is associated with facilitating falling into light sleep, but it also reduces REM and more restorative deep sleep stages.
Circadian rhythms are changes in functioning that take place throughout the day, and most of these are controlled by the body’s biological clock (the suprachiasmatic nucleus, or SCN) (McEwen & Karatsoreos, 2015; Purves, 2008; Sapolsky, 2004). According to NINDS (2014), the SCN is in the hypothalamus, and light that reaches the retinas is sent through chemical signals to the SCN through the optic nerves, which then turns off the production of melatonin (the hormone that makes people feel sleepy as night comes and less light reaches the retina). Use of blue light–emitting technology directly before bed can interrupt this sleep cycle, and with 9 out of 10 Americans reporting the use of at least one device within an hour of going to bed, the issue seems to be widespread across age groups (Cain & Gradisar, 2010; Gradisar et al., 2013). Circadian rhythms can be disrupted from many common experiences (to be discussed in more detail in the stages of development sections of this article), such as jet lag and shift work, and those with blindness can have impaired sleep, such as insomnia, throughout the life course because the retinas do not detect light (NINDS, 2014). There are a number of reasons why individuals are at risk of not meeting sleep duration recommendations (presented in the next section), many of which are addressed throughout the remainder of this article.
Sleep Duration Recommendations
The following guidelines for sleep duration are found in much more detail in the National Sleep Foundation (NSF)’s Final Report (2015). The goal of the panel was “to make scientifically sound and practical recommendations for daily sleep duration across the life span,” and therefore, they devised their recommendations from a review of over 300 peer-review publications from 2004–2014 on sleep duration and health or functioning throughout the life course (Hirshkowitz et al., 2015). In so doing, the panel widened some previously established hour ranges for recommended sleep duration, narrowed others, and added a new category, Young Adults. Importantly, the panel also outlined two related sleep duration ranges: “may be appropriate” (MA), which accounts for individual variation in acceptable sleep duration; and “not recommended” (NR). The following comprises the panel’s final recommendations for sleep duration by stage of development, with the material in parentheses indicating the range for MA and NR:
• 14–17 hours for newborns aged 0–3 months (MA: 11–13; NR: 18–19)
• 12–15 hours for infants aged 4–11 months (MA: 10–11; NR: 16–18)
• 11–14 hours for aged toddlers 1–2 years (MA: 9–10; NR: 15–16)
• 10–13 hours for preschoolers aged 3–5 years (MA: 8–9; NR: 14)
• 9–11 hours for school-aged children aged 6–13 years (MA: 7–8; NR: 12)
• 8–10 hours for teenagers aged 14–17 years (MA: 7; NR: 11)
• 7–9 hours for young adults aged 18–25 years (MA: 6; NR: 10–11)
• 7–9 hours for adults aged 26–64 years (MA: 6; NR: 10)
• 7–8 hours for older adults aged 65 and over (MA: 5–6; NR: 9)
It should also be noted that women during the first trimester of pregnancy may need several hours more sleep than when they are not pregnant (NINDS, 2014). The stages of development sections later in this entry describe findings related to the benefits of sufficient sleep or the potential adverse health and related outcomes associated with insufficient duration of sleep, beginning first with pregnancy and then presenting every stage of development ending with late adulthood.
According to the NSF (2014) Sleep Health Index, only 36% of respondents answered all three questions regarding sleep knowledge correctly (i.e., false): 1—“adults need fewer hours of sleep the older they get”; 2—“successful people need less sleep than the average person”; and 3—“alcohol improves sleep quality.” It is important to note, however, that sleep knowledge did not translate directly into higher sleep quality. At the same point, society also needs to value quality sleep and sufficient sleep durations (Barnes & Drake, 2015; Sapolsky, 2004). Findings from the NSF (2014) indicated that only 18% of individuals would choose to sleep if they had an extra hour in the day.
The Centers for Disease Control and Prevention (CDC) suggest that insufficient sleep presents a public health problem (discussed in more detail in the next section of this article). The CDC therefore paraphrases the following recommendations from the NSF regarding “the promotion of good sleep habits and regular sleep” that is known as sleep hygiene: (a) maintain consistency in sleep and wake schedules each night and day (even on weekends); (b) avoid large meals, caffeine, and alcohol before bed; and (c) avoid nicotine (CDC, 2015a). The NSF also suggests the following to promote good sleep hygiene: (a) avoid napping; (b) engage in vigorous physical exercise in the morning or late afternoon, or more calming exercise like yoga before bed; (c) receive sufficient natural light exposure to maintain a healthy sleep-wake cycle; (d) set and maintain a stable bedtime routine and associate your bed only with sleep (not TV viewing or reading); and (e) make the environment conducive to sleep in terms of temperature, sound, and light (Thorpy, 2016). According to the NSF, practicing good sleep hygiene is important throughout the life course.
Sleep and Public Health
Sufficient sleep matters for the world’s health and productivity (Barnes & Drake, 2015; Mental Health Foundation, 2011; NSF, 2014; Hirshkowitz et al., 2015; Institute of Medicine Committee on Sleep & Research, 2006; Takahashi, 2012). According to the CDC, sleep is increasingly considered pertinent to public health (CDC, 2015a). Large percentages of the world’s population are not receiving sufficient sleep, and insufficient sleep is positively associated with negative health outcomes (Barnes & Drake, 2015; Gradisar et al., 2013; McEwen & Karatsoreos, 2015; Sapolsky, 2004; Takahashi, 2012). The CDC (2015a) reviews research findings suggesting that inadequate sleep and the wake-time sleepiness that stems from it seem to heighten the risk of negative outcomes in three primary areas, including (a) unintended accidents, such as motor vehicle crashes, work errors (occupational or medical), and industrial disasters; (b) increased likelihood of suffering from diseases such as cancer, diabetes, obesity, and hypertension; and (c) comorbid mental health conditions and disorders such as depression. Findings such as these are corroborated from studies pointing to the adverse health outcomes that insufficient sleep has on the brain and body affecting psychosocial relationships, cognition, health, and longevity (Banks & Dinges, 2007; Basner et al., 2013; Bronson & Merryman, 2009; Engle-Friedman, 2014; Gleason, Pierce, Walker, & Warnock, 2013; Institute of Medicine Committee on Sleep & Research, 2006; McEwen & Karatsoreos, 2015; Miller, Lumeng, & LeBourgeois, 2015; Sapolsky, 2004), and are discussed within each section on the life course later in this article.
A report by the Institute of Medicine Committee on Sleep (2006) estimates that between 50 and 70 million Americans suffer from chronic disorders of sleep and wakefulness. In addition, most people in the United States do not have schedules conducive to aiding sleep health and are not meeting the sleep recommendations of the CDC (Barnes & Drake, 2015; CDC, 2015a). Survey (self-report) data in the United States conducted from reports in 2005–2006 and 2007–2008 suggest that the percentage of those reporting sleep-related difficulties fell into a number of categories associated with daily and occupational functioning, including concentration (23.2%), memory (18.2%), working or hobbies (13.3%), transportation (11.3%), taking care of finances (10.5%), and performing work, either employed or volunteer (8.6%) (CDC, 2015a). Another report (CDC, 2011) presented 2009 survey data using the new sleep module that was added to the Behavioral Risk Factor Surveillance System (BRFSS) and found that among 74,571 respondents across 12 states, approximately 35% self-reported fewer than 7 hours of sleep in a 24-hour period, with close to 38% reporting falling asleep unintentionally at least once over the past 30 days (CDC, 2011). Further, according to the NSF’s (2014) Sleep Index, results from a survey conducted in English or Spanish to landlines and cell phones of 1,250 adults in the United States found that average sleep time was 7 hours and 36 minutes, 35% reported their sleep quality as “poor” or “only fair,” and 17% indicated that their physician have told them that they have a sleep disorder (NSF, 2014). National findings from survey work of adolescents suggest that only 31% report receiving at least 8 hours of sleep per night (Eaton, 2010), and insufficient sleep may take neurobehavioral and psychosocial tolls of its own, given that the brain is under development so rapidly and in such a complex way during this stage (Bartel, Gradisar, & Williamson, 2015; Carskadon, Acebo, & Jenni, 2004; Siegel, 2013; Soffer-Dudek, Sadeh, Dahl, & Rosenblat-Stein, 2011).
Although most sleep research stems from and corresponds to Western countries, new findings from developing nations suggest that sleep problems are a public health issue globally. Research in Western countries, as well as a recent large-scale study of 40,000 adults in developing nations in Asia and Africa, suggest that sleep problems are global (Barnes & Drake, 2015; Mental Health Foundation, 2011; NSF, 2014; Stranges, Tigbe, Gomez-Olive, Thorogood, & Kandala, 2012). In survey studies that use self-report conducted in Canada, the United Kingdom, and the United States, the findings suggest that approximately 20% of adult respondents reported problems with sleep, a percentage similar to the 16.6% identified in the 2012 study conducted by the Warwick Medical School of older adults (ages ranging from 50 to 106 years) in low-income settings in eight Asian and African countries (Stranges et al., 2012). The authors of that study point out that based on the finding that 16.6% of older adults in these low-income settings report problems with sleep (considering the increase in the aging population globally), it is possible that 260 million people may be experiencing sleep problems by 2030 (Stranges et al., 2012).
Sleep disorders account for problems with sleep and related adverse behavioral and health outcomes within all stages of the life course. According to the National Institute of Neurological Disorders and Stroke (NINDS, 2014), at least 40 million Americans suffer from enduring sleep disorders every year, with an additional 20 million Americans having occasional sleep disturbances. These disorders and problems with sleep, as well as the sleep deprivation tethered to each one, interrupt and can truncate healthy development and compromise efficacy at work, while driving, and in social settings (NINDS, 2014). In the United States, direct medical costs for sleep disorders are estimated at $16 billion, though that figure would be much larger if indirect costs are considered, such as loss incurred due to reduced productivity (NINDS, 2014).
More than 70 sleep disorders have been described by doctors, although the DSM-5 includes 10 and the ICD-10 has 7 (American Psychiatric Association & American Psychiatric Association DSM-5 Task Force, 2013; WHO, 2015; NINDS, 2014). The recent revision of the DSM diagnostic criteria and conditions for sleep disorder is now more in line with the International Classification of Sleep Disorders, Third Edition (ICSD-3) (American Academy of Sleep Medicine, 2005). In terms of the DSM-5, sleep disorders now encompass conditions that show signs of disturbed sleep, cause distress, and impair daily functioning in order to help professionals determine when outside (American Psychiatric Association & American Psychiatric Association DSM-5 Task Force, 2013). The DSM-5 sleep disorders include insomnia disorder, hypersomnolence disorder, narcolepsy, breathing-related sleep disorders (such as sleep apnea), circadian rhythm sleep disorders, non-REM (NREM) disorders, nightmare disorder, REM sleep behavioral disorder, and restless legs syndrome (RLS), and substance/medication-induced sleep disorder (American Psychiatric Association & American Psychiatric Association DSM-5 Task Force, 2013). The DSM-5 emphasizes that sleep disorders can pose a risk to mental health, and disturbances in sleep can also reflect an underlying medical or neurological condition that needs attention such as Parkinson’s disease or congestive heart failure (American Psychiatric Association & American Psychiatric Association DSM-5 Task Force, 2013; American Psychiatric Association, 2013).
There were some major changes made to the way that the DSM-5 classified and organized sleep disorders, as opposed to the DSM-IV. As noted by the American Psychiatric Association and American Psychiatric Association DSM-5 Task Force (2013), changes to the DSM-5 were aimed to (a) increase the clinical utility of the diagnostic criteria and the definitions for those who are nonspecialists (i.e., general medical practitioners or mental health clinicians); and (b) improve understanding of when a referral to a sleep specialist is needed. Therefore, some sleep conditions that used to be individual are now grouped together, whereas others have been divided founded on increased recognition that the underlying pathologies may be distinct. In addition, because there is an increased understanding that sleep-wake conditions can interact (or coexist) with and mutually exacerbate other mental health or medical conditions, greater emphasis has been placed on the need for independent clinical evaluation of a sleep disorder even when another condition (mental or medical) is present.
There are now both categorical and dimensional assessments of sleep disorders so that the relative severity of the sleep disorder also can be evaluated. The disorders in the ICD-10 include insomnias (G47.0), hypersomnias (G47.1), disorders of the sleep-wake schedule (G47.2), sleep apnea (including central and obstructive) (G47.3), narcolepsy and cataplexy (G47.4), other sleep disorders (G47.8), and sleep disorders unspecified (G47.9). According to NINDS (2014), the most commonly occurring are sleep apnea, RLS, and narcolepsy. These four sleep disorders are described in more detail next, with content summarized from NINDS (2014).
Whether due to stress, diet, or jet lag, insomnia can affect almost anyone on a short-term basis. Insomnia over longer periods, or with frequency, can be debilitating, as it is related to more serious and prolonged sleep debts (NINDS, 2014). Insomnia affects more women than men (about 40% vs. about 30%), and the incidence increases with age. Mild insomnia may be addressed by improving or consistently practicing good sleep hygiene, whereas serious bouts of insomnia are being investigated by research with light therapy and related measures to affect circadian rhythms (NINDS, 2014). A significant change was made to the DSM, such that there is only one classification of insomnia in the DSM-5, unlike the DSM-IV, which included two classifications (primary insomnia and secondary insomnia), with the goal of greater uniformity of diagnosis, and reflected a collaboration between the American Psychiatric Association and the American Association of Sleep Medicine task forces (Khurshid, 2015).
Both the DSM-5 and the ICD-10 include sleep apnea, a condition that includes periods of interrupted breathing during sleep and is sometimes caused by fat buildup or reduced muscle tone (such as with aging), permitting the windpipe to collapse during breathing because muscles relax at the onset of sleep. According to NINDS (2014), approximately 18 million Americans have sleep apnea; however, most have not had the problem diagnosed. Sleep apnea is a serious condition whereby airflow is blocked up to a minute per episode and blood oxygen falls, which leads the brain to awaken the individual, causing the airway muscles to tighten and breathing to resume (often after a snort and the continuation of snoring). This cycle can be repeated hundreds of times during the period of sleep, which means that those with sleep apnea can be very sleepy during the day due to so many repeated awakenings, and also may have symptoms of depression or exhibit changes in their personality (NINDS, 2014). Further, morning headaches due to lack of oxygen during sleep can be present, along with reduction in cognitive functioning and sex drive. Sleep apnea is associated with high blood pressure, irregular heartbeat, increased risk of heart attacks and stroke, increased chance of car accidents (by two to three times), and even sudden death because of respiratory failure in sleep (NINDS, 2014). Sleep apnea can be detected through a polysomnography that can be performed at a sleep center. If mild sleep apnea is diagnosed, weight loss or lack of supine sleep may address it, whereas those with moderate or severe sleep apnea may be prescribed special devices to aid in sleep, such as a continuous positive airway pressure (CPAP) machine, or surgery. Unlike in cases with mild insomnia, where a doctor may prescribe sleeping pills, those with sleep apnea should not take sleep sedatives or sleeping pills because it could prevent their awakening to breathe (NINDS, 2014).
Restless Legs Syndrome (RLS)
Restless legs syndrome (RLS) is one of the most common sleep disorders, especially among older adults, affecting an estimated 12 million Americans (NINDS, 2014). RLS seems to be a familial disorder and causes leg discomfort (such as tingling or crawling sensations) and an urge to move. Leg movement is common in the day, and insomnia can be present at night. Individuals with RLS may also have periodic limb movement disorder (PLMD), a disorder that causes jerking movements (particularly affecting the legs) every 20 to 40 seconds. These repetitions account for many awakenings during a period of sleep. Research suggests that dopamine abnormalities may underlie the symptoms of RLS and PLMD, as the drugs used to treat the disorders affect that neurotransmitter (NINDS, 2014).
According to NINDS (2014), narcolepsy is the least prevalent of the conditions reviewed in this section, affecting an estimated 250,000 Americans. Those with the condition fall asleep (for a duration of under 1 minute to more than 30) at different times in the day, even when sufficient amounts of sleep were accrued during the night. Risk for the disorder seems to be hereditary, with symptoms typically appearing in adolescence. However, it may take time to receive a proper diagnosis, which may be later than the adolescent stage of development. If narcolepsy is diagnosed, then drugs that control the symptoms may be prescribed, and naps during the day may alleviate some of the daytime feelings of sleepiness (NINDS, 2014).
Sleep in the Life Course
Scientists are not completely certain why humans need sleep, but research does suggest that sleep needs to be sufficient in both duration and quality, or else impairments in socioemotional, cognitive, and biological functioning can emerge and can have compounding effects on developmental and health trajectories (Banks & Dinges, 2007; Basner et al., 2013; Engle-Friedman, 2014; Mental Health Foundation, 2011; Sapolsky, 2004). Specifically, animal and human studies suggest that sleep seems important for proper immune functioning, memory and cognitive performance, physical functioning, and mood stability. In addition, NINDS (2014) suggests that if sleep is not sufficient, then neurons may not have adequate energy to function properly or they may become overrun with products that are part of standard cellular activities that the neurons malfunction. At the same time, because sleep is a dynamic rather than passive process, perhaps sleep allows neurons to practice communication actively (NINDS, 2014) or to help with stress response due to the endocrine system functioning during sleep (Born & Fehm, 2000; Sapolsky, 2004). Interestingly, research shows that in children and in young adults, growth hormone is released during sleep, further supporting our understanding of sleep as a dynamic process of construction and restoration (Kato, Murakami, Sohmiya, & Nishiki, 2002; NINDS, 2014) in the life course.
The upcoming sections on stages of development in this article serve to capture some of the most recent research on sleep (both the risks and benefits). The content of these sections does not cover all topics and all populations exhaustively; instead, it is a foundation through which social workers can investigate particular topics or special populations of most relevance to their own work in the field. Further, given the significant changes in attention to sleep-wake disorders in the DSM-5 and groundbreaking research in the neurobiology of sleep across the life course, it is important for social workers to maintain an updated awareness of these diagnostic criteria and research findings in the future. Many findings can be found in freely available, full-text journal articles in pubmed.gov, special reports from the NSF, university and hospital research laboratories that routinely report updated findings (such as the Division of Sleep Medicine at Harvard Medical School), and neuroscience websites with information about sleep translated for the public (such as the Society for Neuroscience’s website Brainfacts.org) that also serve to provide findings relevant to many stages throughout the life course. For more information on sleep duration recommendations by stage of development, and content covering the risks and benefits associated with sufficient sleep within each developmental range beyond what has been included in this entry, please see the NSF’s Final Report (2015).
Pregnancy and Fetal Development
Many bodily and psychological changes that take place during pregnancy interfere with getting sleep of sufficient quality and quantity. The “Women and Sleep” poll conducted in 1998 by the NSF found that 78% of women respondents reported pregnancy as the time in their lives with the most disturbed sleep (NSF, 1998). Sleep can be interrupted or fragmented due to (a) physical discomfort associated with pregnancy (e.g., nausea, heartburn, and back pain); (b) psychological stressors (e.g., worry about the well-being of the fetus or anxiety about labor); and (c) higher levels of oxytocin, which is important for uterine contractions, yet peaks during the night late in pregnancy (Lee, Fuh, & Wang, 2016; Won, 2015). Pregnancy also increases the risk of the sleep disorders that were reviewed earlier in this article, such as RLS and obstructive sleep apnea, which can significantly impair sleep and health, thereby conferring risks of their own during pregnancy (Lee et al., 2016; Rajendiran, Nimesh, Ananthanarayanan, & Dhiman, 2015; Won, 2015). In addition to these factors that may promote sleepiness during the day, high levels of the hormones progesterone and gonadotropin, which help to maintain pregnancy, also promote the feeling of drowsiness during the day and the desire to go to bed early at night (Won, 2015). Restricted sleep (less than six hours) during the final month of pregnancy increases the risk for longer labor and delivery via Cesarean section (Won, 2015). Recently, research has identified napping in the day as a possible protective mechanism for pregnant women, even though it does not seem to improve sleep at night directly (Ebert, Wood, & Okun, 2015). Scholars also suggest the importance of assessing for sleep disturbances early in pregnancy, with a new measure reporting excellent specificity, but needing improvements in sensitivity to make sure that disturbed sleep is not missed by practitioners (Okun, Buysse, & Hall, 2015).
Women who experience pregnancy-specific stressors (i.e., concern about the pregnancy such as outcome or fetus) during the first trimester, show higher levels of cortisol during this stage of the pregnancy (compared to the expected course, where cortisol is elevated during the third trimester to promote fetal lung development), which can be problematic because the placenta cannot filter all the cortisol (Davis & Sandman, 2010). These findings suggest associations with impaired infant mental development, with other studies also finding that heightened maternal stress during pregnancy poses a risk of infant stress regulation and brain development; for example, higher levels of cortisol early in gestation were associated with greater right amygdala volume and more affective problems for girls (but not boys) at age seven (Buss et al., 2012; Davis, Glynn, Waffarn, & Sandman, 2011). Importantly, although we tend to protect newborn sleep, we pay less attention to the importance of sufficient sleep during pregnancy (for mother and fetus) and the years beyond infancy that comprise the rest of the life course (Barnes & Drake, 2015; Bronson & Merryman, 2009; Carskadon, 2011; CDC, 2015a).
Infancy and Toddlerhood
Sleep also needs to be sufficient in quantity and quality to support rather than interfere with postpartum health and functioning. One recent study examined noise levels on maternity wards during postpartum hospital stays and reviewed findings suggesting that the decibel range in hospitals exceeds the recommendations by the World Health Organization (WHO), and furthermore, that high noise levels can be disruptive to both mother and newborn health and bonding (Adatia, Law, & Haggerty, 2014). The authors of that study suggest the introduction of quiet time as part of standard hospital practice for maternity wards, as it could help both parent-offspring dyads and the hospital staff. Postpartum sleep can be fragmented and insufficient for a number of reasons, such as the erratic sleep schedule of newborns and demands of work and daily obligations outside the home, and this restricted sleep can also pose a risk of postpartum depression, which can increase the risk of negative child health outcomes such as insecure attachment (Applegate & Shapiro, 2005; Bhati & Richards, 2015; Cozolino, 2014; Crowley et al., 2015; Farmer, 2009; Okun, 2015; Sit et al., 2015).
Interestingly, infants also seem to need sufficient sleep even to realize that the care their mothers are giving them is in fact sensitive. Specifically, one recent mixed-methods study (e.g., employing both functional neuroimaging and behavioral assessments) found that maternal sensitivity was positively associated with attachment security only for infants who got more sleep at night (Bernier, Belanger, Tarabulsy, Simard, & Carrier, 2014). In that prospective study, maternal sensitivity was also related to infants’ and toddlers’ executive functioning and theory of mind for those who had more sleep. The authors suggest that sleep is an important maturational milestone of infancy, because it seems important for functioning and it may improve the benefits that can come from greater maternal sensitivity (Bernier et al., 2014).
Sleep research has paid significant attention to premature infants. According to the CDC (2015b), 1 in 10 babies is born prematurely in the United States. Sleep disorder and disturbance in pregnant women can increase chances of problems in pregnancy that are associated with preterm delivery (Chang, Pien, Duntley, & Macones, 2010; Facco et al., 2014; Okun et al., 2012; Xu, Feng, Peng, Guo, & Li, 2014), which then poses a risk to the newborn’s biopsychosocial development (Als et al., 2012; McAnulty et al., 2010, 2013; CDC, 2015b). Sleep is also important and can be interrupted for preterm newborns who may need to undergo medical interventions that can cause pain, induce a stress response, and interfere with sleep (Bonan, Pimentel, Tristao, & Campos, 2015). Findings from research studies of full-term babies find that sufficient sleep is positively associated with learning in infancy (such as imitation), social-emotional functioning in infancy and toddlerhood, lexical development in toddlers, and reduced parental stress that can also confer protection in the family environment and spousal relationship (Colvin, Collie-Akers, Schunn, & Moon, 2014; Konrad, Herbert, Schneider, & Seehagen, 2016; Mindell & Lee, 2015; Mindell, Sadeh, Kwon, & Goh, 2015; Reid, Hong, & Wade, 2009; Sadeh, Tikotzky, & Kahn, 2014; Saenz, Yaugher, & Alexander, 2015; Sinai & Tikotzky, 2012; Sorondo & Reeb-Sutherland, 2015; Tikotzky et al., 2015).
According to the NSF, 90% of parents believe that their children are receiving sufficient sleep, yet children are getting on average one hour of sleep less than they did 30 years ago, and kindergartners are averaging 30 minutes less (Bronson & Merryman, 2009). Given that the brain is under construction until the mid-twenties, this lost sleep can have dramatic consequences. For example, in a study where children in elementary school were randomly assigned to go to bed either 30 minutes early or late, cognitive performance between the two groups (who differed in sleep amount by just one hour) showed a two-year gap in favor of the children who were randomly assigned to the go-to-bed-early group (Bronson & Merryman, 2009). Many studies of childhood samples find that insufficient sleep is associated with poorer cognitive performance, such as on neurocognitive tests, in language development, and with executive functioning, as well as impairments in social-emotional functioning, whereas sufficient sleep seems beneficial for all these areas, in addition to motor learning (Bronson & Merryman, 2009; Bub, Buckhalt, & El-Sheikh, 2011; Desrochers, Kurdziel, & Spencer, 2016; Gregory & O’Connor, 2002; Kurdziel, Duclos, & Spencer, 2013; Sadeh et al., 2014, 2015; Williams, Berthelsen, Walker, & Nicholson, 2015).
Findings indicate an association between lower family socioeconomic status (SES) and shorter sleep duration (measured objectively and through reporting) for children and more sleep-wake disturbance, with research demonstrating a possible mediator of greater exposure to environmental sleep conditions that could disturb sleep and more presleep worry as reported by the child participants (Bagley, Kelly, Buckhalt, & El-Sheikh, 2015). The authors suggest that although the findings point to many causes rather than a singular association, addressing some of the environmental concerns by adding a humidifier or fan to the sleep environment might be beneficial, but this idea needs to be empirically evaluated. Scholars also point to the need for more intervention and prevention work regarding sleep and achievement differences based on SES, suggesting that when sleep is compromised, the cognitive functioning and achievement of children from low-SES households may be more adversely affected than may be the case for children from more SES-advantaged households (Buckhalt, 2011).
Adequate sleep is also important for physical health. Children who get insufficient sleep are also at greater risk for obesity, a finding that cannot be explained by a sedentary lifestyle (such as passive TV viewing) alone (Bronson & Merryman, 2009; Spiegel, Tasali, Leproult, & Van Cauter, 2009; Van Cauter & Knutson, 2008). The research identifies a “neuroendocrine cascade” (Spiegel et al. 2009) that takes place such that sleep loss increases ghrelin (a hormone that signals hunger) and decreases leptin (a hormone that signals satiety), and insufficient sleep also signals the release of the stress hormone cortisol, which stimulates the body to produce fat (Spiegel et al., 2009; Van Cauter & Knutson, 2008). Human growth hormone, which is important for breaking down fat, is also disrupted by sleep loss—findings consistent with behavioral studies (from three different countries—Japan, Canada, and Australia) demonstrating that children who get less than 8 hours of sleep per night had a 300% higher rate of obesity compared to those who received 10 hours (Bronson & Merryman, 2009). Slow-wave sleep, which children spend more time in that adults (about 40% vs. about 4%), is important for insulin sensitivity and glucose tolerance, and findings indicate that for participants who are awakened during this stage of sleep, hormone levels rise to the point that would translate to a gain in 20 to 30 pounds (Bronson & Merryman, 2009).
Sleep is also an important consideration for children who meet the diagnostic criteria for a sleep disorder, and for those who are at risk for or who have been diagnosed with a psychiatric condition. Children with primary diagnosis of a psychiatric disorder may also have a sleep disorder or disturbed sleep, and sleep disturbance can also pose risks for psychiatric problems in children without a primary diagnosis of a behavioral health disorder (Alfano & Gamble, 2009; Ramtekkar & Ivanenko, 2015). The relationship between sleep and psychiatric symptoms in childhood is complex and reciprocal, and improving treatments for sleep disorders may also reduce psychiatric symptoms (Alfano & Gamble, 2009). As described earlier in this entry, sleep is important for memory consolidation, yet the place where memories are consolidated depends on the emotional context, whereby negative emotional stimuli are processed by the amygdala (think flight, fight, or freeze responses), whereas both neutral and positive emotional experiences are picked up by the hippocampus (Bronson & Merryman, 2009). As noted earlier, the amygdala remains active during sleep (Sapolsky, 2004), and sleep deprivation negatively affects the hippocampus more than the amygdala, suggesting that we are more likely to attend to and remember the negative rather than the positive when sleep deprived (Bronson & Merryman, 2009; Sapolsky, 2004; Soffer-Dudek et al., 2011).
Adolescence and Young Adulthood
Commencing around the start of puberty and extending until the mid-twenties, the adolescent and young adult brain undergoes a period of significant growth and change in terms of neural connections (overproducing and then pruning) and brain structure, and given that the brain is very much sculpted by experience, it can be vulnerable to the behavioral and neurobiological consequences of insufficient sleep (Carskadon, 2011; Casey, Getz, & Galvan, 2008; Giedd, 2009; Giedd et al., 1999). As stated, 90% of parents believe that their children receive sufficient sleep, yet only 5% of high school students report sleeping 8 hours per day, which is at the low end of the range suggested by the NSF’s 2015 Final Report (Bronson & Merryman, 2009). As children get older and move into adolescence, survey research from around the world suggests that bedtimes get later and that adolescents are more likely to set their own bedtimes (Bronson & Merryman, 2009; Carskadon, 2011; Carskadon et al., 2004). Although young people and their caregivers may believe that sleep debt in the week can be “paid back” by sleeping in on weekends, in fact, this pattern can further perpetuate sleep disturbance (for example, by delaying the onset of sleepiness later on a weekend night) and negatively affect the circadian rhythm involved with sleep (Bronson & Merryman, 2009; Hutchison, 2013).
Further, given that the biological clock of adolescents sends signals to initiate sleep later in the night than it does for children and adults, and that meeting the recommended sleep duration is associated with better neurocognitive, psychosocial, and cognitive outcomes, some school districts have moved to delayed starts for middle and high schools, which parallels the American Association for Pediatrics recommended school start time for adolescents as no earlier than 8:30 a.m. (Bartel et al., 2015; Carskadon, 2011; Minges & Redeker, 2015; Owens, 2014; American Association of Pediatrics, 2014; Soffer-Dudek et al., 2011; Telzer, Fuligni, Lieberman, & Galvan, 2013). The American Association of Pediatrics also recommends that schools pay more attention to physical activity in adolescence, and findings from a recent review found that physical activity was positively associated with adolescents’ sleep (measured both objectively and subjectively) and with findings supporting the association into young adulthood (Lang et al., 2015). In addition, restricted sleep may prompt some adolescents to use substances to stay awake in the day or aid sleep at night (Hutchison, 2013). Given that the adolescent brain is particularly vulnerable to addiction, which itself is associated with brain-based changes and heightened risk for negative impact on trajectories into young adulthood and beyond, addressing adolescents sleep disturbance firsthand (e.g., supporting sleep hygiene, determining whether the presence of a sleep disorder exists, etc.) is important (Casey, Getz, et al., 2008; Casey, Jones, & Hare, 2008; Giedd et al., 1999; Hutchison, 2013; Jacobus & Tapert, 2013; Luciana & Feldstein Ewing, 2015; Owens, 2014).
Research also suggests that sleep deprivation, which can negatively affect adolescents’ capacity for optimal executive functioning, such as decision making, and support attention to and memory for negative stimuli over positive or neutral stimuli, may contribute to the misdiagnosis for attention deficit hyperactivity disorder (ADHD) or depression (Hutchison, 2013; Soffer-Dudek et al., 2011). Insufficient sleep also may increase risk-taking in the adolescent brain, where emotional and cognitive systems are learning a delicate dance of balance (Telzer et al., 2013; Thomas, Monahan, Lukowski, & Cauffman, 2015). One study’s data suggested that compared to adolescents who elected to go to bed earlier and shut off video games, adolescents who stayed up late playing video games demonstrated lower perception of negative consequences for risky choices, as measured by the Cognitive Appraisal of Risky Events (Reynolds et al., 2015). In sum, given that adolescents are the most sleep-deprived population, needing an average of 9.25 hours per night while receiving several hours less than that on average, paying attention to adolescents’ sleep (duration, stability, and quality) matters for health outcomes and transitions into the next phase of the life course (Carskadon, 2011; Hirshkowitz et al., 2015; Hutchison, 2013).
The world is facing a public health problem concerning insufficient sleep (Barnes & Drake, 2015; Mental Health Foundation, 2011; NSF, 2014; Hirshkowitz et al., 2015; CDC, 2015a; Stranges et al., 2012). As described in more detail in earlier sections of this article, chronic sleep disturbance poses problems for mental and physical health, cognitive functioning, work productivity and safety, and social-emotional well-being (Basner et al., 2013; Engle-Friedman, 2014; McEwen & Karatsoreos, 2015; Sapolsky, 2004; Scullin & Bliwise, 2015; Spiegel et al., 2009; Tempaku et al., 2015). Sleep disturbances, disorders, and deprivation, along with related impairments in biopsychosocial functioning, are estimated to cost billions of dollars annually due to direct medical care costs and lost productivity (NINDS, 2014). The following section introduces a range of topics (which may overlap, although they are not organized as such and also may be relevant to other stages of development) and populations to consider when evaluating sleep practices and the policy implications as they affect adults, with particular attention paid to areas of interest in the field of social work. Specifically, topics related to sleep included in this section introduce research regarding discrimination, parenthood and associated stressors, work patterns such as shift work, early life adversity and the life course, mental illness or risk for psychopathology, and incarcerated populations, with a focus on women. Implications for policy are described in the closing section of this article and relate to many of the topics affecting diverse populations reviewed in this section.
Research has begun to examine the association between sleep and discrimination. Discrimination, which is defined as “differential or unfair treatment based on actual or perceived membership in a group,” and which “can occur based on race/ethnicity, national origin, religion, gender, sexual orientation, SES, or other social factors” is recognized as having the potential to negatively affect health outcomes (Slopen, Lewis, & Williams, 2015, p. 1). A recent study examined 17 studies that investigated sleep and discrimination, with the primary goal to evaluate whether the relationship between sleep and discrimination held when taking confounding variables into account (Slopen et al., 2015). In fact, the authors found that even when controlling for important variables such as depression, there was evidence that experiences of discrimination (measured by different instruments depending on the study) were associated with problems with sleep (both self-reported and objectively measured), although the authors suggest that more research is needed to examine the association for different demographic groups and evaluate sleep as linking discrimination to poorer health outcomes (Slopen et al., 2015).
As reviewed earlier in this article, sleep disturbances are an expected (although potentially problematic) part of pregnancy because insufficient sleep can impair biopsychosocial functioning of parents, and such disruptions can negatively affect opportunities for bonding and recognition of maternal sensitivity (Bhati & Richards, 2015; Lawson, Murphy, Sloan, Uleryk, & Dalfen, 2015; Okun et al., 2012; Petzoldt, Wittchen, Einsle, & Martini, 2016; Sinai & Tikotzky, 2012; Sivertsen, Hysing, Dorheim, & Eberhard-Gran, 2015; Sorondo & Reeb-Sutherland, 2015; Won, 2015). Including and beyond the newborn period, however, some parents’ chances of getting insufficient sleep may increase when their infants or older children have chronic medical needs, such as dependence on medical equipment to sustain life, or conditions such as asthma that require parental vigilance or reduce quality of sleep due to worry throughout the night (Cheezum et al., 2013; Meltzer & Mindell, 2006). For example, in one study of 40 parents whose children had asthma, 12.5% of caregivers’ scores on the Epworth Sleepiness Scale indicated that they met the criteria for a sleep disorder, and 42.5% reported excessiveness sleepiness that could also affect daytime functioning (Cheezum et al., 2013). The authors suggest that parental sleep is an underrecognized yet important consideration for families with chronically ill children.
Work patterns also may affect sleep habits, duration, and quality, with negative associations for health and mental health trajectories increasing for those who engage in shift work (Sapolsky, 2004; Takahashi, 2012; Ulhoa, Marqueze, Burgos, & Moreno, 2015). Estimates suggest that 20% of those actively employed in North America and Europe have jobs that involve shift work, and those who do shift work have poorer health behaviors (e.g., smoking, poor diet, sedentary life) than those whose employment is stable and takes place during the day (Ulhoa et al., 2015). There is likely a complex relationship between health behaviors and other factors that underlie these health disparities and behaviors between the two work groups (shift and nonshift). It could be that shift work interrupts circadian rhythms and disrupts endocrine function, as studies find change in many hormones (such as concentrations of melatonin, cortisol, ghrelin, and leptin) in those engaged in shift work (Ulhoa et al., 2015).
Recall that ghrelin is involved in signaling hunger, whereas leptin signals satiety, and disruption with either hormone (or both of them) could have implications for hunger, satiety, and obesity (Bronson & Merryman, 2009; Sapolsky, 2004; Van Cauter & Knutson, 2008). Further, melatonin is important for the synthesis and the activity of insulin, and reduced melatonin (which may occur due to lack of exposure to evening/night during these periods of work) could be related to insulin resistance and heightened risk for diabetes (Ulhoa et al., 2015; Van Cauter & Knutson, 2008). Finally, shift work also could contribute to poor health behaviors (being sedentary or having a poor diet), and could increase stress that could implicate more cortisol (a stress hormone) in the bloodstream (Ulhoa et al., 2015). Some considerations for addressing work schedules are raised in the closing section, on policy.
Poor sleep quality and quantity in middle adulthood are also associated with earlier experiences in the life course, such as traumatic brain injury (Duclos, Beauregard, Bottari, Ouellet, & Gosselin, 2015; Vermaelen, Greiffenstein, & deBoisblanc, 2015) or adverse childhood experiences (ACES) and impaired sleep in adulthood (Kajeepeta, Gelaye, Jackson, & Williams, 2015). Given that poor sleep can be a risk factor for poorer mental health outcomes, keeping sleep on the radar of providers is important. One recent study found that for those adults admitted to psychiatric intensive care units (PICUs), there was great intra-individual variability in sleep duration each night, and yet overall amount of sleep on the first night was negatively associated with length of stay, although this relationship held most reliably for those patients with schizophrenia (Langsrud, Vaaler, Kallestad, & Morken, 2016). These findings are consistent with other work showing the associations between instable, poor sleep and schizophrenia symptomatology (Kamath, Virdi, & Winokur, 2015), suggesting that stabilizing sleep should be a priority for providers working with psychiatric patients (Langsrud et al., 2016).
Poor sleep and sleep disturbances also have been identified in incarcerated populations. Although most recent research has examined these associations in males, a recent study explored the sleep of female prisoners in a maximum-security prison in the United States (Harner & Budescu, 2014). First, it should be noted that those women entering prison can show health disparities that can be negatively affected by poor sleep while in prison (meaning exacerbating current problems and perhaps contributing to new or more chronic health problems) (Braithwaite, Treadwell, & Arriola, 2005; Harner & Budescu, 2014). The researchers employed a cross-sectional design and assessed sleep quality and risk for sleep apnea as measured by the Pittsburgh Sleep Quality Index and the Multivariable Apnea Prediction Score. The results suggested that of the 438 female participants, 72% of them met the criteria for “poor sleepers” and 10% had a probability score of higher than .5 to meet the criteria for sleep apnea. Similar to findings from other studies reviewed in this article with groups from various populations at different stages of development, the female participants indicated that the following factors contributed to their experience of poor sleep: (a) worry/thinking, (b) environmental conditions, (c) pain or physical health conditions, (d) nightmares/flashbacks, and (e) absence of sleep medication consumption (Harner & Budescu, 2014). Not only can impaired sleep on an ongoing basis negatively influence health and mental health problems (preexisting or new), but as the authors point out, the benefit that these women may potentially receive from engaging in prison programming may be reduced (Harner & Budescu, 2014).
Although the suggested range for sleep duration allows for slightly less sleep in older adults than those in middle adulthood, sleep restriction and disorder can still negatively affect health and mental health in late adulthood (Gleason et al., 2013; Gooneratne & Vitiello, 2014; Rodriguez, Dzierzewski, & Alessi, 2015; Scullin & Bliwise, 2015; Zdanys & Steffens, 2015) and sleep seems associated with neurodegenerative disease such as Alzheimer’s (Ju, Lucey, & Holtzman, 2014). When working with older adults, it is very important to distinguish between changes in sleep duration that are part of normative aging (and do not impair daytime functioning) and interrupted sleep and sleep disorder (that are not an expected part of aging and do impair daily functioning). In fact, epidemiologic studies suggest that an estimated 50% of older adults have problems with sleep, and even though insufficient sleep can have adverse health consequences, sleep problems in late adulthood can be overlooked or assumed to be an expected part of the normal aging process (Gooneratne & Vitiello, 2014; Rodriguez et al., 2015; Zdanys & Steffens, 2015). The two most common sleep disorders in late adulthood are insomnia and sleep apnea, and both need better diagnosis and clinical treatment in this population, for they do not reflect normal aging and in the case of sleep apnea, might not present with the common risk factors such as snoring and obesity seen in younger age groups (Gooneratne & Vitiello, 2014; Rodriguez et al., 2015). Research suggests that among older adults, 5% meet the criteria for insomnia and 20% meet the criteria for sleep apnea (Gooneratne & Vitiello, 2014). Studies also suggest that cognitive behavioral therapies can be particularly effective in addressing insomnia and may be preferred if effective because drugs to address sleep disturbances also may have psychomotor effects (Gooneratne & Vitiello, 2014).
Older adults with medical conditions may also be at greater risk of difficulty with sleep. For example, a study in Australia using self-reports of 10,721 women aged 70–75 found that those with chronic disease had increased risk of problems with sleep (Leigh, Hudson, & Byles, 2016). Moreover, arthritis and heart disease were the best predictors of impairments with sleep in this population (Leigh et al., 2016). Importantly, in hospital settings, sleep can be disturbed (see, for example, the findings from the maternity ward in the section “Pregnancy and Fetal Development”). Sleep problems seem to be of particular concern in the intensive care unit (ICU) setting with very old adults (aged 80 and over), where these patients may be given sedative-hypnotic drugs to address problems of insomnia and disturbed sleep, even though these drugs can have negative effects for those in very late adulthood (Sterniczuk, Rusak, & Rockwood, 2014). At the same time, it is important to recall from research described earlier that sleep and depression can mutually exacerbate one another (Sapolsky, 2004), and therefore special attention to sleep disturbance may be needed for older adults who present with both medical conditions and depression (Gleason et al., 2013). In sum, although sleep disturbances seem more common in older adults than younger groups, these impairments do not represent age-expected changes if they copresent with impairment in daily functioning and daytime sleepiness (Gooneratne & Vitiello, 2014).
As outlined in this article, sleep disturbances and disorders pose risks for negative outcomes to biopsychosocial developmental trajectories throughout the life course. The CDC (2011, 2015a) suggests that there are many reasons why individuals do not get enough sleep, such as work schedules that are at odds with a stable and sufficient sleep pattern, technologies that keep them up late into the night and disturb their bodily rhythms, and sleep disorders that may not receive proper diagnosis or optimal and timely treatment. In recent years, the CDC, the Institute of Medicine, and the National Center on Sleep Disorders Research have independently supported the development of ways to expand attention to sleep patterns and outcomes in the United States.
In recognition of the importance of sleep to the nation’s health, CDC surveillance of sleep-related behaviors has increased in recent years. In addition, the Institute of Medicine encouraged collaboration between CDC and the National Center on Sleep Disorders Research to support development and expansion of adequate surveillance of the U.S. population’s sleep patterns and associated outcomes. The reports stemming from these organizations underscore the widespread nature of sleep disturbance nationally, while a recent study in Africa and Asia shows evidence of sleep disturbance as a global issue (CDC, 2011, 2015a; Stranges et al., 2012).
The CDC (2011) outlines several implications of findings on sleep for public health, including the need for (a) greater public attention and awareness, (b) increased research, (c) training of healthcare workers, and (d) environmental factors associated with improved sleep. A recent perspective article points to five specific topics to prioritize sleep health with implications for public health policy (Barnes & Drake, 2015). First, the authors suggest that school schedules need to be adjusted to reflect the needs of sleep in older groups of children and adolescents, which corroborated by research (Minges & Redeker, 2015) and supported by the American Academy of Pediatrics (American Association of Pediatrics, 2014). Second, some work schedules are not conducive to sleep (for example, consider findings from the studies on shift work), and although napping may help employees, it is not a common practice everywhere and may not be supported by employers (Barnes & Drake, 2015; Takahashi, 2012; Ulhoa et al., 2015). The authors also recommend that we need to improve access to education regarding sleep and to treatments for sleep disorders (Barnes & Drake, 2015). Given that sleep is so important to health, functioning, and productivity, and that sleep disturbance appears to be a problem globally (and may have different implications depending on settings or populations) (Barnes & Drake, 2015; CDC, 2015a; Stranges et al., 2012), policy work suggests both proximal and distal avenues for improving sleep health, with many implications for clinical and macro practices in social work.
Adatia, S., Law, S., & Haggerty, J. (2014). Room for improvement: Noise on a maternity ward. BMC Health Services Research, 14, 604.Find this resource:
Alfano, C. A., & Gamble, A. L. (2009). The role of sleep in childhood psychiatric disorders. Child Youth Care Forum, 38(6), 327–340.Find this resource:
Als, H., Duffy, F. H., McAnulty, G., Butler, S. C., Lightbody, L., Kosta, S., & Warfield, S. K. (2012). NIDCAP improves brain function and structure in preterm infants with severe intrauterine growth restriction. Journal of Perinatology, 32(10), 797–803.Find this resource:
American Academy of Pediatrics. (2014). School start times for adolescents. Pediatrics, 134(3), 642–649.Find this resource:
American Academy of Sleep Medicine. (2005). The international classification of sleep disorders: diagnostic and coding manual (2d ed.). Westchester, IL: American Academy of Sleep Medicine.Find this resource:
American Psychiatric Association. (2013). Sleep-wake disorders fact sheet.Find this resource:
American Psychiatric Association, & American Psychiatric Association DSM-5 Task Force. (2013). Diagnostic and statistical manual of mental disorders: DSM-5 (5th ed.). Washington, DC: American Psychiatric Association.Find this resource:
Applegate, J. S., & Shapiro, J. R. (2005). Neurobiology for clinical social work: Theory and practice. New York: W.W. Norton.Find this resource:
Bagley, E. J., Kelly, R. J., Buckhalt, J. A., & El-Sheikh, M. (2015). What keeps low-SES children from sleeping well: The role of presleep worries and sleep environment. Sleep Medicine, 16(4), 496–502.Find this resource:
Banks, S., & Dinges, D. F. (2007). Behavioral and physiological consequences of sleep restriction. Journal of Clinical Sleep Medicine, 3(5), 519–528. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1978335/pdf/jcsm.3.5.519.pdf.Find this resource:
Barnes, C. M., & Drake, C. L. (2015). Prioritizing sleep health: Public health policy recommendations. Perspectives on Psychological Science, 10(6), 733–737.Find this resource:
Bartel, K. A., Gradisar, M., & Williamson, P. (2015). Protective and risk factors for adolescent sleep: a meta-analytic review. Sleep Medicine Review, 21, 72–85.Find this resource:
Basner, M., Rao, H., Goel, N., & Dinges, D. F. (2013). Sleep deprivation and neurobehavioral dynamics. Current Opinions on Neurobiology, 23(5), 854–863.Find this resource:
Bernier, A., Belanger, M. E., Tarabulsy, G. M., Simard, V., & Carrier, J. (2014). My mother is sensitive, but I am too tired to know: Infant sleep as a moderator of prospective relations between maternal sensitivity and infant outcomes. Infant Behavior and Development, 37(4), 682–694.Find this resource:
Bhati, S., & Richards, K. (2015). A systematic review of the relationship between postpartum sleep disturbance and postpartum depression. Journal of Obstetric, Gynecologic, and Neonatal Nursing, 44(3), 350–357.Find this resource:
Bonan, K. C., Pimentel Filho Jda, C., Tristao, R. M., Jesus, J. A., & Campos Junior, D. (2015). Sleep deprivation, pain, and prematurity: A review study. Arq Neuropsiquiatr, 73(2), 147–154.Find this resource:
Born, J., & Fehm, H. L. (2000). The neuroendocrine recovery function of sleep. Noise Health, 2(7), 25–38.Find this resource:
Braithwaite, R. L., Treadwell, H. M., & Arriola, K. R. (2005). Health disparities and incarcerated women: A population ignored. American Journal of Public Health, 95(10), 1679–1681.Find this resource:
Bronson, P., & Merryman, A. (2009). NurtureShock: New thinking about children. New York: Twelve Books.Find this resource:
Brown, R. E., Basheer, R., McKenna, J. T., Strecker, R. E., & McCarley, R. W. (2012). Control of sleep and wakefulness. Physiological Reviews, 92(3), 1087–1187.Find this resource:
Bub, K. L., Buckhalt, J. A., & El-Sheikh, M. (2011). Children’s sleep and cognitive performance: A cross-domain analysis of change over time. Developmental Psychology, 47(6), 1504–1514.Find this resource:
Buckhalt, J. A. (2011). Insufficient sleep and the socioeconomic status achievement gap. Child Development Perspectives, 5(1), 59–65.Find this resource:
Buss, C., Davis, E. P., Shahbaba, B., Pruessner, J. C., Head, K., & Sandman, C. A. (2012). Maternal cortisol over the course of pregnancy and subsequent child amygdala and hippocampus volumes and affective problems. Proceedings of the National Academy of Sciences USA, 109(20), E1312–1319.Find this resource:
Cain, N., & Gradisar, M. (2010). Electronic media use and sleep in school-aged children and adolescents: A review. Sleep Medicine, 11(8), 735–742.Find this resource:
Carskadon, M. A. (2011). Sleep in adolescents: The perfect storm. Pediatric Clinics of North America, 58(3), 637–647.Find this resource:
Carskadon, M. A., Acebo, C., & Jenni, O. G. (2004). Regulation of adolescent sleep: implications for behavior. Annals of the New York Academy of Sciences, 1021, 276–291.Find this resource:
Casey, B. J., Getz, S., & Galvan, A. (2008). The adolescent brain. Developmental Review, 28(1), 62–77.Find this resource:
Casey, B. J., Jones, R. M., & Hare, T. A. (2008). The adolescent brain. Annals of the New York Academy of Sciences, 1124, 111–126.Find this resource:
Centers for Disease Control and Prevention (CDC). (2011). Morbidity and mortality weekly report. Retrieved from http://www.cdc.gov/mmwr/PDF/wk/mm6008.pdf.
Centers for Disease Control and Prevention (CDC). (2015a). Insufficient sleep is a public health problem. Retrieved from http://www.cdc.gov/features/dssleep/.
Centers for Disease Control and Prevention (CDC). (2015b). National Prematurity Awareness Month. Retrieved from http://www.cdc.gov/features/prematurebirth/.
Chang, J. J., Pien, G. W., Duntley, S. P., & Macones, G. A. (2010). Sleep deprivation during pregnancy and maternal and fetal outcomes: Is there a relationship? Sleep Medicine Review, 14(2), 107–114.Find this resource:
Cheezum, R. R., Parker, E. A., Sampson, N. R., Lewis, T. C., O’Toole, A., Patton, J., & Keirns, C. C. (2013). Nightwatch: Sleep disruption of caregivers of children with asthma in Detroit. Journal of Asthma & Allergy Educators, 4(5), 217–225.Find this resource:
Colvin, J. D., Collie-Akers, V., Schunn, C., & Moon, R. Y. (2014). Sleep environment risks for younger and older infants. Pediatrics, 134(2), e406–412.Find this resource:
Cozolino, L. J. (2014). The neuroscience of human relationships: Attachment and the developing social brain (2d ed.). New York: W.W. Norton & Company.Find this resource:
Crowley, S. K., Morrow, A. L., Schiller, C. E., Stuebe, A., Nau, S. L., & Girdler, S. S. (2015). Biopsychosocial vulnerability to postpartum depression: A laboratory-based feasibility study of sleep dysregulation, daytime stress reactivity, and anxiety symptomology during pregnancy. Psychoneuroendocrinology, 61, 56.Find this resource:
Davis, E. P., Glynn, L. M., Waffarn, F., & Sandman, C. A. (2011). Prenatal maternal stress programs infant stress regulation. Journal of Child Psychology and Psychiatry, 52(2), 119–129.Find this resource:
Davis, E. P., & Sandman, C. A. (2010). The timing of prenatal exposure to maternal cortisol and psychosocial stress is associated with human infant cognitive development. Child Development, 81(1), 131–148.Find this resource:
Desrochers, P. C., Kurdziel, L. B., & Spencer, R. M. (2016). Delayed benefit of naps on motor learning in preschool children. Experimental Brain Research, 234(3), 763–772.Find this resource:
Duclos, C., Beauregard, M. P., Bottari, C., Ouellet, M. C., & Gosselin, N. (2015). The impact of poor sleep on cognition and activities of daily living after traumatic brain injury: A review. Australian Occupational Therapy Journal, 62(1), 2–12.Find this resource:
Eaton, D. K. (2010). Youth risk behavior surveillance—United States, 2009. Retrieved from http://www.cdc.gov/mmwr/pdf/ss/ss5905.pdf.
Ebert, R. M., Wood, A., & Okun, M. L. (2015). Minimal effect of daytime napping behavior on nocturnal sleep in pregnant women. Journal of Clinical Sleep Medicine, 11(6), 635–643.Find this resource:
Engle-Friedman, M. (2014). The effects of sleep loss on capacity and effort. Sleep Science, 7(4), 213–224.Find this resource:
Facco, F. L., Ouyang, D. W., Zee, P. C., Strohl, A. E., Gonzalez, A. B., Lim, C., & Grobman, W. A. (2014). Implications of sleep-disordered breathing in pregnancy. American Journal of Obstetric Gynecology, 210(6), 559.e1–6.Find this resource:
Farmer, R. L. (2009). Neuroscience and social work practice: The missing link. Los Angeles: SAGE.Find this resource:
Giedd, J. N. (2009). Linking adolescent sleep, brain maturation, and behavior. Journal of Adolescent Health, 45(4), 319–320.Find this resource:
Giedd, J. N., Blumenthal, J., Jeffries, N. O., Castellanos, F. X., Liu, H., Zijdenbos, A., & Rapoport, J. L. (1999). Brain development during childhood and adolescence: A longitudinal MRI study. Nature Neuroscience, 2(10), 861–863.Find this resource:
Gleason, O. C., Pierce, A. M., Walker, A. E., & Warnock, J. K. (2013). The two-way relationship between medical illness and late-life depression. Psychiatric Clinics of North America, 36(4), 533–544.Find this resource:
Gooneratne, N. S., & Vitiello, M. V. (2014). Sleep in older adults: Normative changes, sleep disorders, and treatment options. Clinics in Geriatric Medicine, 30(3), 591–627.Find this resource:
Gradisar, M., Wolfson, A. R., Harvey, A. G., Hale, L., Rosenberg, R., & Czeisler, C. A. (2013). The sleep and technology use of Americans: findings from the National Sleep Foundation’s 2011 Sleep in America poll. Journal of Clinical Sleep Medicine, 9(12), 1291–1299.Find this resource:
Gregory, A. M., & O’Connor, T. G. (2002). Sleep problems in childhood: A longitudinal study of developmental change and association with behavioral problems. Journal of the American Academy of Child and Adolescent Psychiatry, 41(8), 964–971.Find this resource:
Harner, H. M., & Budescu, M. (2014). Sleep quality and risk for sleep apnea in incarcerated women. Nursing Research, 63(3), 158–169.Find this resource:
Harvard Medical School. Why sleep matters. Retrieved from http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep.
Hirshkowitz, M., Whiton, K., Albert, S. M., Alessi, C., Bruni, O., DonCarlos, L., & Ware, J. C. (2015). National Sleep Foundation updated sleep duration recommendations: Final report. Sleep Health: Journal of the National Sleep Foundation, 1(4), 233–243.Find this resource:
Hutchison, E. D. (2013). Essentials of human behavior: Integrating person, environment, and the life course. Los Angeles: SAGE.Find this resource:
Institute of Medicine Committee on Sleep Medicine & Research. (2006). The National Academies Collection: Reports funded by National Institutes of Health. In H. R. Colten & B. M. Altevogt (Eds.), Sleep disorders and sleep deprivation: An unmet public health problem. Washington, DC: National Academies Press/National Academy of Sciences.Find this resource:
Jacobus, J., & Tapert, S. F. (2013). Neurotoxic effects of alcohol in adolescence. Annual Review of Clinical Psychology, 9, 703–721.Find this resource:
Ju, Y. E., Lucey, B. P., & Holtzman, D. M. (2014). Sleep and Alzheimer disease pathology—a bidirectional relationship. Nature Reviews Neurology, 10(2), 115–119.Find this resource:
Kahn, M., Sheppes, G., & Sadeh, A. (2013). Sleep and emotions: Bidirectional links and underlying mechanisms. International Journal of Psychophysiology, 89(2), 218–228.Find this resource:
Kajeepeta, S., Gelaye, B., Jackson, C. L., & Williams, M. A. (2015). Adverse childhood experiences are associated with adult sleep disorders: A systematic review. Sleep Medicine, 16(3), 320–330.Find this resource:
Kamath, J., Virdi, S., & Winokur, A. (2015). Sleep disturbances in schizophrenia. Psychiatric Clinics of North America, 38(4), 777–792.Find this resource:
Kato, Y., Murakami, Y., Sohmiya, M., & Nishiki, M. (2002). Regulation of human growth hormone secretion and its disorders. Internal Medicine, 41(1), 7–13.Find this resource:
Khurshid, K. A. (2015). A review of changes in DSM-5 sleep-wake disorders. Retrieved from http://www.psychiatrictimes.com/special-reports/review-changes-dsm-5-sleep-wake-disorders.
Konrad, C., Herbert, J. S., Schneider, S., & Seehagen, S. (2016). The relationship between prior night’s sleep and measures of infant imitation. Developmental Psychobiology, 58(4), 450–461.Find this resource:
Kurdziel, L., Duclos, K., & Spencer, R. M. (2013). Sleep spindles in midday naps enhance learning in preschool children. Proceedings of the National Academy of Sciences USA, 110(43), 17267–17272.Find this resource:
Lang, C., Kalak, N., Brand, S., Holsboer-Trachsler, E., Puhse, U., & Gerber, M. (2015). The relationship between physical activity and sleep from mid adolescence to early adulthood. A systematic review of methodological approaches and meta-analysis. Sleep Medicine Review, 28, 28–41.Find this resource:
Langsrud, K., Vaaler, A. E., Kallestad, H., & Morken, G. (2016). Sleep patterns as a predictor for length of stay in a psychiatric intensive care unit. Psychiatry Research, 237, 252–256.Find this resource:
Lawson, A., Murphy, K. E., Sloan, E., Uleryk, E., & Dalfen, A. (2015). The relationship between sleep and postpartum mental disorders: A systematic review. Journal of Affective Disorders, 176, 65–77.Find this resource:
Lee, W. L., Fuh, J. L., & Wang, P. H. (2016). Sleep disorders in pregnancy. Journal of the Chinese Medical Association, 79(1), 3–4.Find this resource:
Leigh, L., Hudson, I. L., & Byles, J. E. (2016). Sleep difficulty and disease in a cohort of very old women. Journal of Aging Health, 28(6), 1090–1104.Find this resource:
Luciana, M., & Feldstein Ewing, S. W. (2015). Introduction to the special issue: Substance use and the adolescent brain. Developmental impacts, interventions, and longitudinal outcomes. Developmental Cognitive Neuroscience, 16, 1–4.Find this resource:
McAnulty, G. B., Duffy, F. H., Butler, S. C., Bernstein, J. H., Zurakowski, D., & Als, H. (2010). Effects of the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) at age 8 years: Preliminary data. Clinical Pediatrics (Philadelphia), 49(3), 258–270.Find this resource:
McAnulty, G., Duffy, F. H., Kosta, S., Weisenfeld, N. I., Warfield, S. K., Butler, S. C., & Als, H. (2013). School-age effects of the newborn individualized developmental care and assessment program for preterm infants with intrauterine growth restriction: Preliminary findings. BMC Pediatrics, 13, 25.Find this resource:
McEwen, B. S., & Karatsoreos, I. N. (2015). Sleep deprivation and circadian disruption: stress, allostasis, and allostatic load. Sleep Medicine Clinics, 10(1), 1–10.Find this resource:
Meltzer, L. J., & Mindell, J. A. (2006). Impact of a child’s chronic illness on maternal sleep and daytime functioning. Archives of Internal Medicine, 166(16), 1749–1755.Find this resource:
Mental Health Foundation. (2011). Sleep matters: The impact of sleep on health and well being. Retrieved from https://www.mentalhealth.org.uk/sites/default/files/MHF-Sleep-Report-2011.pdf
Miller, A. L., Lumeng, J. C., & LeBourgeois, M. K. (2015). Sleep patterns and obesity in childhood. Current Opinion in Endoctrinology, Diabetes, and Obesity, 22(1), 41–47.Find this resource:
Mindell, J. A., & Lee, C. (2015). Sleep, mood, and development in infants. Infant Behavior and Development, 41, 102–107.Find this resource:
Mindell, J. A., Sadeh, A., Kwon, R., & Goh, D. Y. (2015). Relationship between child and maternal sleep: a developmental and cross-cultural comparison. Journal of Pediatric Psychology, 40(7), 689–696.Find this resource:
Minges, K. E., & Redeker, N. S. (2015). Delayed school start times and adolescent sleep: A systematic review of the experimental evidence. Sleep Medicine Review, 28, 82–91.Find this resource:
National Institutes of Health (NIH). (2013). The benefits of slumber. Retrieved from https://newsinhealth.nih.gov/issue/apr2013/feature1.
National Institute of Neurological Disorders and Stroke (NINDS). (2014). Brain basics: Understanding sleep. Retrieved from http://www.ninds.nih.gov/disorders/brain_basics/understanding_sleep.htm.
National Sleep Foundation (NSF). (1998). Women and sleep. Retrieved from https://sleepfoundation.org/sleep-topics/pregnancy-and-sleep.
National Sleep Foundation (NSF). (2014). 2014 sleep health index. Retrieved from https://sleepfoundation.org/sites/default/files/2014%20Sleep Health%20Index-FINAL_0.PDF.
Okun, M. L. (2015). Sleep and postpartum depression. Current Opinions in Psychiatry, 28(6), 490–496.Find this resource:
Okun, M. L., Buysse, D. J., & Hall, M. H. (2015). Identifying insomnia in early pregnancy: Validation of the Insomnia Symptoms Questionnaire (ISQ) in pregnant women. Journal of Clinical Sleep Medicine, 11(6), 645–654.Find this resource:
Okun, M. L., Luther, J. F., Wisniewski, S. R., Sit, D., Prairie, B. A., & Wisner, K. L. (2012). Disturbed sleep, a novel risk factor for preterm birth? Journal of Women’s Health (Larchmont), 21(1), 54–60.Find this resource:
Owens, J. (2014). Insufficient sleep in adolescents and young adults: an update on causes and consequences. Pediatrics, 134(3), e921–932.Find this resource:
Petzoldt, J., Wittchen, H. U., Einsle, F., & Martini, J. (2016). Maternal anxiety versus depressive disorders: specific relations to infants’ crying, feeding and sleeping problems. Child Care Health Development, 42(2), 231–245.Find this resource:
Purves, D. (2008). Neuroscience. 4th ed. Sunderland, MA: Sinauer.Find this resource:
Rajendiran, S., Nimesh, A., Ananthanarayanan, P. H., & Dhiman, P. (2015). Markers of oxidative stress in pregnant women with sleep disturbances. Oman Medical Journal, 30(4), 264–269.Find this resource:
Ramtekkar, U., & Ivanenko, A. (2015). Sleep in children with psychiatric disorders. Seminars in Pediatric Neurology, 22(2), 148–155.Find this resource:
Reid, G. J., Hong, R. Y., & Wade, T. J. (2009). The relation between common sleep problems and emotional and behavioral problems among 2- and 3-year-olds in the context of known risk factors for psychopathology. Journal of Sleep Research, 18(1), 49–59.Find this resource:
Reynolds, C. M., Gradisar, M., Kar, K., Perry, A., Wolfe, J., & Short, M. A. (2015). Adolescents who perceive fewer consequences of risk-taking choose to switch off games later at night. Acta Paediatrica, 104(5), e222–227.Find this resource:
Rodriguez, J. C., Dzierzewski, J. M., & Alessi, C. A. (2015). Sleep problems in the elderly. Medical Clinics of North America, 99(2), 431–439.Find this resource:
Sadeh, A., De Marcas, G., Guri, Y., Berger, A., Tikotzky, L., & Bar-Haim, Y. (2015). Infant sleep predicts attention regulation and behavior problems at 3–4 years of age. Developmental Neuropsychology, 40(3), 122–137.Find this resource:
Sadeh, A., Tikotzky, L., & Kahn, M. (2014). Sleep in infancy and childhood: implications for emotional and behavioral difficulties in adolescence and beyond. Current Opinions in Psychiatry, 27(6), 453–459.Find this resource:
Saenz, J., Yaugher, A., & Alexander, G. M. (2015). Sleep in infancy predicts gender specific social-emotional problems in toddlers. Frontiers in Pediatrics, 3, 42.Find this resource:
Sapolsky, R. M. (2004). Why zebras don’t get ulcers. 3d ed. New York: Times Books.Find this resource:
Scullin, M. K., & Bliwise, D. L. (2015). Sleep, cognition, and normal aging: Integrating a half century of multidisciplinary research. Perspectives on Psychological Science, 10(1), 97–137.Find this resource:
Siegel, D. J. (2013). Brainstorm: The power and purpose of the teenage brain. New York: Jeremy P. Tarcher/Penguin.Find this resource:
Sinai, D., & Tikotzky, L. (2012). Infant sleep, parental sleep, and parenting stress in families of mothers on maternity leave and in families of working mothers. Infant Behavior and Development, 35(2), 179–186.Find this resource:
Sit, D., Luther, J., Buysse, D., Dills, J. L., Eng, H., Okun, M., & Wisner, K. L. (2015). Suicidal ideation in depressed postpartum women: Associations with childhood trauma, sleep disturbance and anxiety. Journal of Psychiatric Research, 66–67, 95–104.Find this resource:
Sivertsen, B., Hysing, M., Dorheim, S. K., & Eberhard-Gran, M. (2015). Trajectories of maternal sleep problems before and after childbirth: A longitudinal population-based study. BMC Pregnancy and Childbirth, 15, 129.Find this resource:
Slopen, N., Lewis, T. T., & Williams, D. R. (2015). Discrimination and sleep: A systematic review. Sleep Medicine, 18, 88–95.Find this resource:
Soffer-Dudek, N., Sadeh, A., Dahl, R. E., & Rosenblat-Stein, S. (2011). Poor sleep quality predicts deficient emotion information processing over time in early adolescence. Sleep, 34(11), 1499–1508.Find this resource:
Sorondo, B. M., & Reeb-Sutherland, B. C. (2015). Associations between infant temperament, maternal stress, and infants’ sleep across the first year of life. Infant Behavior and Development, 39, 131–135.Find this resource:
Spiegel, K., Tasali, E., Leproult, R., & Van Cauter, E. (2009). Effects of poor and short sleep on glucose metabolism and obesity risk. Nature Reviews Endocrinology, 5(5), 253–261.Find this resource:
Sterniczuk, R., Rusak, B., & Rockwood, K. (2014). Sleep disturbance in older ICU patients. Clinical Interventions in Aging, 9, 969–977.Find this resource:
Stranges, S., Tigbe, W., Gomez-Olive, F. X., Thorogood, M., & Kandala, N. B. (2012). Sleep problems: An emerging global epidemic? Findings from the INDEPTH WHO-SAGE study among more than 40,000 older adults from 8 countries across Africa and Asia. Sleep, 35(8), 1173–1181.Find this resource:
Takahashi, M. (2012). Prioritizing sleep for healthy work schedules. Journal of Physiological Anthropology, 31, 6.Find this resource:
Telzer, E. H., Fuligni, A. J., Lieberman, M. D., & Galvan, A. (2013). The effects of poor quality sleep on brain function and risk taking in adolescence. Neuroimage, 71, 275–283.Find this resource:
Tempaku, P. F., Mazzotti, D. R., & Tufik, S. (2015). Telomere length as a marker of sleep loss and sleep disturbances: a potential link between sleep and cellular senescence. Sleep Medicine, 16(5), 559–563.Find this resource:
Thomas, A. G., Monahan, K. C., Lukowski, A. F., & Cauffman, E. (2015). Sleep problems across development: A pathway to adolescent risk taking through working memory. Journal of Youth and Adolescence, 44(2), 447–464.Find this resource:
Thorpy, M. (2016). Sleep hygiene. Retrieved from https://sleepfoundation.org/ask-the-expert/sleep-hygiene.
Tikotzky, L., Sadeh, A., Volkovich, E., Manber, R., Meiri, G., & Shahar, G. (2015). Infant sleep development from 3 to 6 months postpartum: Links with maternal sleep and paternal involvement. Monographs of the Society for Research in Child Development, 80(1), 107–124.Find this resource:
Ulhoa, M. A., Marqueze, E. C., Burgos, L. G., & Moreno, C. R. (2015). Shift work and endocrine disorders. International Journal of Endocrinology, 2015, 826249.Find this resource:
Van Cauter, E., & Knutson, K. L. (2008). Sleep and the epidemic of obesity in children and adults. European Journal of Endocrinology, 159(Suppl. 1), S59–66.Find this resource:
Vermaelen, J., Greiffenstein, P., & deBoisblanc, B. P. (2015). Sleep in traumatic brain injury. Critical Care Clinics, 31(3), 551–561.Find this resource:
Williams, K. E., Berthelsen, D., Walker, S., & Nicholson, J. M. (2015). A developmental cascade model of behavioral sleep problems and emotional and attentional self-regulation across early childhood. Behavioral Sleep Medicine, 1–21.Find this resource:
Won, C. H. (2015). Sleeping for two: The great paradox of sleep in pregnancy. Journal of Clinical Sleep Medicine, 11(6), 593–594.Find this resource:
World Health Organization. (WHO). (2015). International classification of diseases (ICD-10). Retrieved from http://apps.who.int/classifications/icd10/browse/2016/en%20-%20/G47.0.
Xu, T., Feng, Y., Peng, H., Guo, D., & Li, T. (2014). Obstructive sleep apnea and the risk of perinatal outcomes: A meta-analysis of cohort studies. Scientific Reports, 4, 6982.Find this resource:
Zdanys, K. F., & Steffens, D. C. (2015). Sleep disturbances in the elderly. Psychiatric Clinics of North America, 38(4), 723–741.Find this resource: