Sleepdeprivationetc.

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Sleep Deprivation, Disorders and the Function of Sleep Thesis: This paper aims to disprove the idea that the quality of sleep is most important and enforce the idea of a correct length of time, or quantity, of human sleep, that correct length being somewhere between seven and eight hours, in order to avoid the occurance of sleep disorders. In the past, humans faced great dangers when attempting to get a full night of sleep. Nowadays, we have houses and nice beds that help make an extended period of uninterrupted sleep possible. Carol Worthman claims that is it not necessarily the amount of sleep a person gets, but how well they sleep. This paper aims to disprove the idea that the quality of sleep is most important and enforce the idea of a correct length of time, or quantity, of human sleep, that correct length being somewhere between seven and eight hours, in order to avoid the occurance of sleep disorders. A large number of studies have been conducted to determine the functions of sleep and how lack of sleep or sleep disorders is detrimental to a person’s health. Worthman (2008) explains that prehistoric peoples “relied on protection from tools, social groupings, then fire, and eventually physical structures to fend off predators during waking and sleeping” because bipedalism made maneuvering in trees more difficult for hominids. Ground-sleeping is much more dangerous than sleeping in trees. Not much evidence of sleep sites have been found in the archaeological record. However, the earliest archaeological evidence of bedding was found “in an open-air camp, Ohalo II (23,000-year-old site, Sea of Galilee, Israel). The in situ bedding remains were exposed on a brush hut floor, around a hearth” (Nadel et al., 2004, p. 6821). This example of a prehistoric bed proves that sleeping by hearths was important in prehistory as a form of protection. Since prehistoric people faced many dangers from predators, it is very likely that they were unable to sleep for solid amounts of time

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like we do today. It is also likely that prehistoric people slept for small amounts of time and possibly even in shifts. Carol Worthman (2008) writes, “the hallmarks of sleep-like behavior include characteristic posture, reduced activity, altered arousal thresholds, and homeostatic regulation manifested in rebound or compensatory responses after rest/sleep deprivation.” (p. 296) It is interesting to note the compensatory responses after rest/sleep deprivation. Sleep occurs in different stages throughout its duration. Basically, sleep is broken down into rapid eye movement (REM) sleep and nonrapid eye movement (NREM) sleep. It is during REM sleep that dreaming occurs. As discussed in Worthman (2008) NREM sleep consists of four stages which lead to REM sleep, two stages of drowsy, light sleep followed by two stages of slow wave sleep. Worthman points out that “the contrast between external and internal activity states becomes greatest in REM sleep, during which a very active brain occupies and immobilized body.” (p. 293) The idea of a very active brain during stages of sleep is interesting to consider because most people associate sleep with inactivity. However, that is hardly the case, especially in REM sleep. Keeping the brain active may be one of the reasons why sleep is so important. Getting an inadequate amount of sleep leads to a number of different physical problems known as sleep disorders. Carol Worthman (2008) explained that “sleep problems constitute a personal and a public concern: they do not only affect mental and physical health and well-being, but also represent a major source of traffic and work-related accidents and errors, and lateness or low productivity at work or school.” (p. 301). The recommended amount of sleep for adults is somewhere between seven or eight hours a night. Consequences arise if an individual sleeps for less time than the seven to eight hour recommendation. Interestingly, if an individual sleeps

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more than the recommended amount of time, there are also consequences. The importance of sleep is hard to relay because the actual function of sleep in not positively known. Many theories have arisen to explain the function of sleep, but the real reason we sleep is not known for sure. Although many studies have proved that getting more or less than the recommended seven to eight hours of sleep a night is detrimental to human health, the “warnings about sleep restriction are unlikely to be effective so long as people have ‘good reasons’ for their sleep habits and problems that are firmly founded in the ambient triggers to vigilance or reward that maintain wakefulness.” (313) The reasoning behind this most likely lies with the fact that the real reason why we as humans need to sleep is unknown. Also, Americans especially are leading very busy lives and desire to get numerous tasks done that their work time spills over into their sleep time. People want to reap the benefits of their hard work and therefore, they do not mind losing a couple hours of sleep here and there. Most people do not take into consideration the physical side effects inadequate sleep can cause. Besides the normal daytime drowsiness there are more severe ailments that can occur, which will be explained in more detail later. As discussed in Kushida (2005), theories, or hypotheses, for the true function of sleep include: the body restitution hypothesis, vital physiological function, homeostatic model, and learning and memory. Ian Oswald, “believed that brain repair occurs during REM sleep and that NREM sleep exists for bodily restitution” (Kushida, 2005, p. 40). Therefore, sleep is mainly used to help repair parts of the body that are damaged during periods of waking. However, not many studies have been conducted concerning this idea, making this hypothesis not very conclusive. Next, the vital physiological function idea, explains that with sleep deprivation, there is a breakdown of the immune system and prolonged lack of sleep can lead to death. However, Kushida (2005) only explains one study that was conducted in rats, not humans, which

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may suggest that either this model is newer than others or that it is not as widely accepted.

The main evidence that sleep is homeostatically regulated is that sleep deprivation produces: (a) an increase in the tendency to go to sleep (sleepiness or sleep drive) that becomes more pronounced as sleep deprivation is extended, and (b) an increase in the duration of sleep during the recovery period following sleep deprivation. (Kushida, 2005, p. 482-483)

The idea of sleep being regulated homeostatically is quite interesting because it presents information that sleep is restorative, which is also provided in Karmanova (1977). The relationship between learning and memory and sleep can be learned through examining “the subsequent cognitive or motor performance as well as on recall of learned material” (Kushida, 2005, p. 207) of an individual before and after a period of sleep deprivation or sleep loss. As explained in Kushida (2005) sleep loss and deprivation does aid in decreasing an individual’s performance. The cognitive impact of sleep deprivation is “gaps in attention and responsiveness, rapid decay in performance on tasks, reduced capacity for multitasking, errors in perception and response, increased variability in performance, and impaired executive functioning, working memory, and emotion regulation” (Durmer and Dinges, 2005 as quoted in Worthman, 2008). These consequences of sleep loss happen to a majority of people in their everyday lives. These seemingly small impacts can actually lead to more complex problems, such as sleep disorders, which lead to health issues.

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In assessing sleep disorders, questionaires and sleep logs are helpful aids used by clinicians to assess the situation. Also used in assessing sleep disorders is a sleep history, which recounts events that take place in the evening, during the night, in the morning and during the daytime. It is important to learn about events in the patient’s daily life, such as useage of medication, drugs or alcohol, as well as incidents of drowsiness throughout the day (Thorpy 1988). These factors are important in learning about what could be contributing to the disruption or loss of sleep, which in turn are important in assessing the sleep disorder and finding a way to cure it. There are four classifications of sleep disorders as explained in Thorpy (1988), they are as follows: Disorders of Initiating and Maintaining Sleep (DIMS), Disorders of Excessive Somnolence (DOES), Disorders of the Sleep-Wake Schedule (DSWS), and Disfunctions associated with sleep, sleep stages, or partial arousal, also known as parasomnias (Thorpy, 1988). Disorders of Initiating and Maintaining Sleep all “produce a disruption of the internal structure of nocturnal sleep” (Thorpy, 1988, p. 17). Disorders of Excessive Somnolence are disorders associated with sleepiness during the daytime. Sleep-Wake Disorders are those that represent a disruption of the normal rhythms of the sleep-wake cycle. Parasomnias deal with specific stages of the sleep cycle and are different from Sleep-Wake Disorders because they do not disrupt the normal rhythms of the sleep-wake cycle. One of the most common sleep disorders is Insomnia. Simply put, insomnia is when an individual does not get the appropriate amount of sleep each night. Often times, insomnia is considered to be a lack of sleep. In some cases, an individual may not sleep at all for a night or two, but a persistent lack of sleep would result in death. Therefore, insomnia is not a complete absense of sleep, but a persistent lack of the appropriate amount of sleep. Furthermore, insomnia

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is most prevalent in individuals of old age and female and stress is thought to be a contributing factor. When treating insomnia, behavioral and pharmacological therapies are used. Behavioral therapies include promoting correct sleep hygiene (Colten and Altevogt, 2006). Pharmacological therapies consist of the use of hypnotic agents. Similar to insomnia is the idea of sleep loss, which means obtaining less than the recommended seven to eight hours of sleep per night. In America, most people are constantly busy with their jobs and family life, making sleep loss very common. Sleep loss can produce many effects that are detrimental to an individual’s health. It has been discovered that there may be a link between sleep loss and obesity, as well as diabetes, depression, and alcohol use (Colten and Altevogt, 2006). In Colten and Altevogt (2006), information was provided on a study that related sleep loss with obesity. Individuals who slept less than six hours a night, more often had a higher body mass index, or BMI. Similarly, another study concluded that those who slept more or less than 7.7 hours a night, had a higher BMI (Colten and Altevogt, 2006). The link between insufficient sleep and obesity is that not getting enough sleep stimulates the appetite. There are two hormones that affect appetite, leptin, which helps suppress appetite, and ghrelin, which stimulates appetite. Not sleeping for the recommended amount of time produces lower levels of leptin and higher levels of ghrelin, which in turn causes people to consume more food and contributes to obesity. Interstingly, this study not only provides a link between sleep loss and obesity but also oversleeping and obesity as well. Apparently, to avoid health problems, an individual must sleep between seven and eight hours a night, no more and no less. Two studies, as presented in Colten and Altevogt (2006), showed that less sleep on average meant that individuals were more likely to have diabetes. One of these studies showed that sleep deprivation led to impaired glucose tolerance in healthy individuals, even after the six

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days over which the study was conducted (Colten and Altevogt, 2006). Evidence of impaired glucose tolerance in healthy indivduals after only six nights of sleep deprivation enforces the relationship between sleep deprivation and diabetes. Similarly, diabetes is also associated with obesity, and since sleep loss and deprivation is proven to cause obesity, the risk of diabetes is even greater. Similar to adults, children can also be affected by sleep disorders. Often times, the idea that sleep disorders are the root of other biological problems is overlooked in children. In children sleep disorders can also be associated with epilepsy. As elaborated upon in Sheldon (2000), seizures result in interrupted or fragmented sleep, which is a contributing factor in their association with sleep disorders. Sleep-related nonepyleptic disorders are refered to as parasomnias (Sheldon 2000). Overall, to help avoid the risk of health problems, poor output at work or school and accidents, whether in an automobile or at the workplace, maintaining the recommended amount of sleep, seven to eight hours a night, is essential. After even a few nights of inadequate sleep, symptoms of sleep disorders can become present. The fact that we sleep on beds inside house structures is important to our ability to sleep for the appropriate amount each night, unlike our prehistoric ancestors who did not have the same advantages that we do. It is important that we make use of those advantages which greatly contribute to our ability to sleep for prolonged periods of time. Often times when experiencing health problems, inadequate sleep is not always our first guess when it comes to finding the root of the problem. However, sleeping for seven to eight hours a night can greatly lessen the risks for certain health problems and even prevent them from happening altogether.