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Section 2: Sleep and Health

As we have noted, it can be very difficult to motivate clients to place a higher priority on getting a good night’s sleep. It is a little overly dramatic and pessimistic to tell our clients that they will probably not live as long if they neglect their sleep – even though that is generally an accurate statement. The medical effects from too little sleep have been quite well researched and documented, and these effects can actually be quite profound and have impacts on many aspects of a person’s health. It is for this reason, questions about sleep should always be part of any comprehensive psychosocial assessment process, and clinicians should compare this information with their client’s reports about any medical problems being experienced.

If there are clear associations between the client’s medical issues and sleep insufficiency, it supports our efforts to build motivation towards better sleep hygiene. However, to discuss such associations with professional authority, we must have clarity ourselves about the connections that exist.  Towards this end, let us look at what is known about the medical effects of sleep deprivation and what are the myths and misperceptions in this area.

We will begin this section with another handout that can be distributed to clients, one that covers in layman’s terms the important health benefits of getting enough sleep. The handout will support the efforts of the clinician to increase motivation for reducing sleep insufficiency. The level of knowledge in the handout will not be sufficient of itself for mental health clinicians to generate professional authority. However, a higher level of professional authority can be generated by understanding and conveying the additional information to follow the handout.


The Surprising Benefits of Sleep

  1. Sleep helps you maintain a strong immune system. According to the Journal of the American Medical Association, people who get fewer than 7 hours of sleep per night are three times more likely to catch colds than people who get 7 or more hours of sleep. Sleep deprivation hurts immune function and makes you more vulnerable to disease.
  2. Sleep helps your weight management. Adequate amounts of sleep increase the amount of an appetite-curbing hormone called leptin in your system, and also decrease the amount of an appetite increasing hormone called ghrelin. A good night of sleep makes it easier to control your appetite. Some studies show that people who get enough sleep on average have a Body Mass Index almost two points lower than sleep deprived individuals.
  3. Sleep helps slow down the aging process and will increase the odds of you extending your life. Sleep deprivation increases the amount of stress hormones in your system, which leads to an increase in cell damage. Sleep deprivation also lowers levels of a growth hormone necessary for cell repair, causing increased aging of your cells.
  4. Sleep helps prevents diabetes. Sleep deprivation increases the amount of insulin resistance a person has. Increased insulin resistance is a precursor to type-2 diabetes.
  5. Sleep helps improve your memory and concentration. The dreaming portion of your sleep cycle is very important for storing memories, and during some of the other parts of your sleep cycle, your brain cells shut down and repair any damage done during the day. This helps to restore your brain functioning and keeps your concentration and focus sharper.
  6. Sleep helps control your blood pressure and prevent heart problems. A new study suggests that insomniacs who average less than five hours of sleep per night have a 500 times greater risk for high blood pressure than people who average more than six hours of sleep. Additionally, sleep helps to prevent the build-up of cholesterol, protecting your heart health.
  7. Sleep helps improve your mood. People with high levels of sleep problems have a higher risk of depression, substance abuse problems and even suicide.
  8. Sleep helps your skin stay younger, healthier and smoother. Repair of your skin tissue only occurs when you are sleeping. Enough sleep allows your body time to repair damage done to your skin by UV rays.
  9. Sleep may help prevent certain kinds of cancer. One of the chemicals of sleep, melatonin, may help suppress certain kinds of cancerous tumors. Melatonin is secreted by your body as part of your sleep cycle, but the amount of melatonin is reduced if you are exposed to light – so keep your bedroom dark when you sleep.
  10. Sleep helps reduce inflammation, and inflammation is believed to be one of the factors contributing to heart problems, arthritis, and many other medical problems.


We do not fully understand why sleep is so essential to health; we just know that it is. Curiously, research has discovered that there is a correlation between how much sleep any animal needs and how fully developed the animal is at birth. Animals born in a very under-developed state seem to require a great deal of sleep. For instance, dogs and cats, which are born blind and helpless at birth, typically average around thirteen hours per day. The king of the sleepers is the koala, sleeping about 22 hours per day.

On the other side of the scale, animals that are born virtually fully developed, appear to require many fewer hours of sleep. Elephants function perfectly well on about 4 hours of sleep while giraffes average only a few minutes of sleep per day. People fall somewhere in between, with 7-8 hours a day seeming to be optimal for most adults.

There is some preliminary evidence that life expectancy itself is affected by getting inadequate amounts of sleep. An often cited research study of over 1.1 million men and women determined that subjects who had less than six hours of sleep a night had an increased risk of mortality over subjects who slept 7 hours per night. (Kripke et al., 2002)

Curiously, subjects who slept more than 8 hours per night also had an increased risk of mortality – in fact a higher risk than those who got less than 7 but more than 4.5 hours of sleep. The increased mortality risk was 15% for people getting more than 8, the same increase as those getting less than 3.5-4.5 hours of sleep. (Kripke et al., 2002)

The authors of this research study were very clear in noting that the correlation between sleep amount and morbidity was not designed to be interpreted as a definitively causal relationship. However, other research might be helpful in explaining the increased risk for shortened life-expectancy related to inadequate sleep. Particularly when our clients show some of the deleterious health effects, it can be useful to educate them about why sleep insufficiency may be partially responsible.


Sleep for Cellular Growth and Repair

During our time asleep, there are a number of processes occurring that are important to the maintenance of our health and well-being. Cellular repair, particularly in important areas in the brain, occurs during certain stages of the sleep cycle. The release of adequate amounts of specific hormones that regulate energy, affect metabolic and endocrine functions, and stimulate growth are likewise dependent upon our bodies moving through various stages of sleep.

When adequate sleep is not occurring, or when there is suppression of adequate amounts of time spent in specific stages of sleep, the body’s self-regulatory and self-repair functions are diminished, and the effects can be widespread and profound.

There are four major areas of health with which research has clearly established correlations to sleep deprivation:


Diabetes (Type-II)

Hypertension and associated cardiovascular risks

Suppression of the immune system


In order to allow trainees to have intelligent conversations with clients about each of these health risks, it may be helpful to discuss the mechanisms through which inadequate sleep might contribute to each of these risks. We will try to do this while keeping the heavy science to a minimum.

Obesity and Sleep

There are five major hormones connected to weight and weight management that are affected by the amount and quality of sleep a person is getting. It can significantly increase the professional authority of the mental health clinician to be able to name each of these and discuss them intelligently with clients. We have already identified leptin and ghrelin in our handout, but there are three other important contributors to the development of obesity as a result of sleep deprivation. All together, these five are:

Growth hormone



Orexin (hypocretin)


Growth hormone is a major determinant in whether the body’s energy is going to be converted to increased muscle mass or into fat. Growth hormone is secreted almost exclusively during the kind of deep sleep that occurs only in the first two full sleep cycles of the night. If there are interruptions to this secretion, it reduces the amount of growth hormone that is released into the bloodstream.

For children and adolescents, this growth hormone is vital to the extent to which children will reach their full potential height, weight and muscular development as they move into and through puberty. For everyone - including adults - the regular release of growth hormone is a key contributor towards the maintenance and repair of muscles and the retention of muscle mass. In fact, growth hormone is also important for other kinds of cellular repair, including in the brain. However, its effects on muscle mass are more directly tied to problems with obesity.

Adults who are regularly sleep deprived suffer decreases in this key hormone and are more likely to incur losses in their muscle mass and increase the amount and ratio of fat in their bodies. This, in turn, decreases the overall metabolic rate – since muscle requires more energy to maintain than does fat – and inclines the body towards fat increases and obesity.

Leptin and ghrelin are two hormones that are intricately tied into the regulation of appetite. Leptin is the chemical messenger that signals the body when enough food has been eaten and triggers the satiation response. When a person has had a good night’s sleep, there is increased availability of this hormone and a person is more likely to feel full after a reasonably sized meal. This assists with weight control.

Ghrelin, on the other hand, is the hormone that triggers the hunger response. A good night’s sleep reduces the amount of this chemical in a person’s bloodstream, thus reducing the sensations of hunger that a person experiences. If a person does not have a good night’s sleep, the level of ghrelin increases. This makes a person feel more hunger and makes for a more difficult time managing a right-sized caloric intake.

Orexin (also known as hypocretin) is a chemical that appears to have several important and complex functions in the body and brain. Based upon the research, some of the functions of the orexin systems appear to include integrating information about whether someone is getting too little sleep over time – creating something called “sleep debt” – and influencing decisions about whether to keep the body alert and awake. An increase in the production of orexin causes increases in wakefulness and alertness.

Without sufficient orexin, the body has a hard time staying awake. Recent research has made a connection between orexin and narcolepsy. The most common form of narcolepsy is caused by a malfunction of orexin producing cells in the brain, taking away the chemicals that help create wakefulness.

Additionally, orexin appears to play an important role in feeding behavior and reward systems (Tsujino & Sakurai, 2009), meaning this chemical is likely involved in food cravings for people who have a very hard time controlling their appetite.  Orexin also has a role in setting the rate of certain metabolic processes that help determine whether energy is converted to fat or burned off as heat, meaning orexin is one of the keys to why some people can eat as much as they like without gaining weight, while other people have to be on a starvation diet not to gain weight. 

Ghrelin increases the activation of orexin. This makes sense, because if a person has not had a good night’s sleep, then there is a need for extra chemical help in maintaining a state of alertness and wakefulness. However, the increase in orexin can also contribute to increases in appetite and caloric intake, increasing the risk of over-eating that contributes to obesity. 

When all of a person’s systems are in good balance, the increase in appetite caused by the orexin systems are offset by a corresponding increase in metabolic rate: a person eats more, but their metabolism is set higher and the extra calories are burned up. The orexin systems integrate the information about the person’s metabolic inputs and outputs with information about the degree of sleep deprivation present and try to strike the right balance to maintain a good homeostasis. (Tsujino & Sakurai, 2009),

However, when too much sleep deprivation occurs, this delicate balance can be thrown off. Then the increase in the ghrelin-orexin combination can lead to disruptions in the homeostasis and an increased risk of appetite increases and over-eating.

There are other chemical systems operating within this effort to maintain a healthy homeostasis. If there were no checks on orexin, we would never fall asleep. However, a number of chemicals in our bodies work to inhibit the orexin systems. One of the most important of these is adenosine, whose fundamental role is to help turn off the orexin systems as part of our biological clock.

Adenosine is a chemical that steadily increases in our blood the longer we have gone without sleep, keeping track of our “sleep debt”. As the amount of adenosine rises, it increasingly inhibits the orexin systems, allowing for wakefulness and alertness to be dialed down so a person can drift off to sleep.

If the orexin systems are on high alert, it can take a lot of adenosine to turn those systems down. However, if sleep debt accumulates high enough, then our bodies will eventually build up enough adenosine to make sleep happen.

Just as a side note, there are other chemical molecules that fit into the same receptor sites in the brain where adenosine works.  The most common of these is caffeine. If caffeine molecules get into those receptor sites, they block the effects of adenosine and help keep a person’s alertness machinery working overtime. This is why caffeine keeps you alert and why it is recommended that a person avoid caffeine later in the day. It blocks the effects of adenosine, allowing orexin to remain active and keeping a person awake. However, even when adenosine is being blocked by caffeine, it continues to build in a person’s overall chemistry.  When caffeine is processed and removed from a person’s system, there is an adenosine driven crash.

The orexin system is also inhibited by three important chemicals that function as neurotransmitters and are involved in the regulation of mood and anxiety disorders: GABA, serotonin and norepinephrine. (Tsujino & Sakurai, 2009) When a person is calm, not overly depressed, and relatively free from stress and anxiety, these neurotransmitters are present in good supply in the brain and will help keep the orexin system in good balance.

However, when a person is in distress, these neurotransmitters can be affected in important ways. Stress, depression and anxiety can have significant effects on GABA, serotonin and norepinephrine, and can reduce their presence in the bloodstream. (Tsujino & Sakurai, 2009), The decrease in availability of these chemicals can result in a reduction in how much orexin will be inhibited, allowing the body to move into a higher state of alert and energy consumption.

This makes sense, because when the body is in distress, it means that there are challenges to be faced and it is helpful to have the body enter a mode of higher alert. This can disrupt the balance, though, and affect whether a person is able to relax enough to get a good night’s sleep.

There are a number of studies that have implicated the orexin systems in both anxiety and panic disorders, as the body’s “thermostat” can get set a little too high in responding to challenges. But the interaction between these three neurotransmitters and the orexin systems also contributes to the tendency for people to gain weight in times of distress.

The orexin systems also appear to be excited by the presence of other chemicals that are related to obesity. Hypoglycemia appears to stimulate the release of orexin, triggering changes in the degree to which hunger is present, and further adding to the possibility of weight gain. (Tsujino & Sakurai, 2009) This means that a person who is hypoglycemic is likely to experience some sleep difficulties.

Decreases in the amount of sleep from the hypoglycemia can then lead to further increases in ghrelin – activating more orexin – and further decreases in leptin, GABA, serotonin, and norepinephrine. A vicious cycle of increased sleeplessness, increased anxiety/depression and increased appetite can become established. This is a good recipe for problems with appetite and weight control with concurrent sleep disturbing anxiety.

When medications like the SSRIs and the SNRIs are used to help bring these systems back into balance, they also help to create more balance with the orexin system. This can help improve sleep and restore balance to these interacting chemical systems. Some researchers have suggested that the primary positive effects of antidepressants result from their ability to improve sleep.

There is another potential problem related to obesity for which increases in the orexin systems are involved. As we have noted, orexin production also appears to be increased by insulin driven hypoglycemia. As weight increases and affects a person’s overall metabolic processes, hypoglycemia becomes more likely. The presence of hypoglycemia then leads to increases in the activity of the orexin systems, leading to increased appetite and diminished control over food intake. This can contribute to another vicious cycle in which orexin is a key player.

These systems are likely deeply involved in binge eating disorders (BED). A large percentage of people with BED have a history of chronic distress and depression, and may have developed metabolic problems that include hypoglycemia and diabetes. The ghrelin-orexin nexus can create such powerful feelings of hunger that desires for eating become all but irresistible.

In line with this understanding, one of the many symptoms of hypoglycemia and diabetes is a noticeable increase in sleep difficulties and disturbances. Additionally, it is has demonstrated that up to half of people with eating disorders also have some degree of sleep disturbance. (Taheri et al.) It is likely that the relationship between hypoglycemia and the orexin systems is involved in this: as hypoglycemia increases, it contributes to increases in the activity of the orexin systems, which lead to problems with sleep.

The decreases in time spent sleeping then contribute to further effects on leptin, ghrelin, GABA, serotonin, and norepinephrine, and the cycles of mood disruption, appetite increase and increased nighttime wakefulness feed off of each other. Over and above instances of eating disorders, it is now believed that sleep deprivation is a major contributor to increases in the overall rate of obesity in this country, based upon this constellation of metabolic and neurochemical processes. (Taheri et al.)

It is entirely possible for this vicious cycle of neurochemical changes to be triggered by an initial period of extended sleep disturbance from which a person is unable to extricate themselves. That initial period of sleeplessness may be the result of a triggering period of stress, anxiety or trauma, or the result of other physiological processes that disturb this complex chemical balance, such as thyroid disease, substance use, or medications that interfere with sleep. Or it may simply be the result of external events that get in the way of good sleep hygiene.

As clinicians, it is important for us to have enough expert knowledge to provide a thorough explanation of how this cycle of sleeplessness, mood disturbance and weight gain can occur. This will allow us both to normalize periods of time when our clients are having difficulties re-establishing a healthy sleep schedule, and advocate for placing a higher priority on good sleep hygiene.

There is one other chemical contributor to this cycle that warrants mention here: cortisol. As most clinicians know, this hormone is a major contributor to problems with mood and anxiety regulation, especially when it comes to the physical effects of long-term stress. It is for this reason that cortisol is frequently referred to as the “stress hormone.” As we noted in our handout, there is a stress hormone that can lead to increased cell damage when insufficient sleep occurs. Cortisol is that stress hormone.

In’s course, Stress and Stress Management: An In-depth Guide for Mental Health Clinicians, we covered in some detail the complex actions of this chemical that is released in greater amounts during periods of high stress. While its purpose is to help recruit additional sources of energy for the body to utilize in its attempts to manage periods of challenge, it has some very destructive effects on the body and brain if it remains present in a person’s systems in large amounts over extended periods of time. It can even lead to the destruction of neurons in the brain, as well as to the prevention of new neuronal connections being formed. 

Apart from its role in periods of high stress, cortisol is an active and useful player in helping to regulate the body’s normal functions for moving through the day. However, cortisol is designed to operate within the functioning of the circadian rhythms that control our wake-sleep cycle. Cortisol levels are designed to rise in the morning – partnering with adrenaline and other body chemicals - as we move towards waking and bringing energy to our day.

But cortisol is also supposed to decline in the evening as we move towards our period of sleep. Like orexin, cortisol is involved in working to secure sources of energy for managing challenges. When our bodies need to move towards more restful and restorative states, cortisol becomes a potentially destructive problem instead of a useful resource.

This is important because we are not designed to operate only in challenge mode. If we stay in challenge mode too long, our bodies begin to break down, and unfortunate things happen at the chemical and cellular level. We also need for our bodies to be able to enter stages of our diurnal rhythm where cellular repair can occur.

Not surprisingly, cortisol tends to work in opposition to growth hormone, one of the other chemicals we mentioned as being important for cellular growth and repair. For growth hormones to be operating at their most effective levels, cortisol levels need to be reduced, otherwise the release of growth hormone is inhibited. Our diurnal rhythms have things set up so that cortisol levels are usually at their lowest right around midnight - exactly the time when growth hormone levels are at their highest levels. This is what allows our growth hormone to work towards maximum cellular growth and repair, working to keep us healthy and young.

When cortisol levels remain too high due to stress and anxiety, it not only interferes with our ability to get to sleep, it also interferes with our ability to engage in cellular repair. This is why cortisol is considered such a major player in stress related physical effects.

And how are levels of cortisol reduced in the body? The most effective way to bring cortisol levels under control is through adequate sleep. Many of the body’s regulating systems move into operation during the normal sleep cycle, including those mechanisms that help levels of cortisol to be brought under control. A good night’s sleep is the easiest, cheapest, and most effective way to practice good stress management, cortisol reduction, and decreases in the risk of associated weight and appetite problems.

Two studies bear noting here. First, a University of Chicago study noted that subjects getting 6.5 hours of sleep per night had cortisol levels that were 50% higher than subjects getting 7.5-8.5 hours of sleep per night. (Leproult) This is a very substantial difference based upon simply 1-2 more hours of sleep.

A similar study conducted at Yale University noted that men living on less than 6 hours of sleep per night doubled their risk of weight gain and diabetes over control subjects who got a full night’s sleep. Increased cortisol and concommitant insulin resistance were the reasons noted for these increased risks.

This ties back into another key effect of cortisol relevant to this section. Studies have demonstrated that excess levels of cortisol can lead to increases in body fat, in particular body fat situated around a person’s mid-section – the proverbial “spare tire”. (Vgontzas )For reasons still being studied, this particular variety of adipose tissue – or fat – in this particular location of the body appears to be particularly responsive to elevated levels of cortisol. The more stress a person is experiencing, the more likely that they will convert extra calories into fat that creates a “spare tire”.

In turn, this “spare tire” contributes to further elevations in the level of cortisol present in the bloodstream, as fat in this part of the body itself produces more cortisol. (Vgontzas ) It is as if they body is creating an additional mechanism for cortisol to be made available to handle periods of heightened stress and challenge.

There is an additional negative effect of these processes. Excess cortisol can make it harder for insulin to be delivered to muscles, increasing the risk for insulin resistance and diabetes. The price that the body pays for operating at a high level of challenge includes overall metabolic effects that are extremely damaging.

Twenty-first century life is not well designed for how our bodies are supposed to work. The combination of too many calories readily available, pervasive and persistent sources of stress, and lowered priority for getting a good night’s sleep create a perfect storm for metabolic problems with serious health consequences. While a good night’s sleep is not the only point of impact for resolving this perfect storm, it is entirely in the middle of what has gone wrong, and can be a very powerful contributor for creating improvements.

Please note that this section is not a full explanation for all of the chemical events that are responsible for increases in the risk of weight gain due to sleep deprivation. There are at least 23 other metabolic and neurotransmission molecules present in our bodies that interact in some way just with the orexin systems, and cortisol has at least as complex interactions with many other systems in the body. If you wished to draw a diagram that showed all of the interacting relationships, it would have so many elements that it would cease to serve a useful function. It would be too much to keep track of.

For this reason, we have only addressed the basics. This section is designed to serve more as a way to place some evidence-based science behind the assertion that sleep deprivation can have important effects on weight and obesity. As we will see, some of the same contributors are involved in other negative effects of too little sleep.


Type-II Diabetes and Sleep

There is not a perfect correlation between obesity and Type-II diabetes. (Type-I diabetes is an autoimmune disease where the body's own immune system attacks and destroys insulin producing cells in the pancreas, triggered by as yet not fully understood mechanisms.) There are obese people who never develop this form of diabetes and persons with Type-II diabetes who are not obese. However, according to a very influential study in the New England Journal of Medicine, about 90% of Type-II diabetes is attributable to excess weight. Some of the same processes we have discussed earlier in this section appear to have connections to this fact, and for this reason there is an important relationship between insufficient sleep and Type-II diabetes. Two widely cited articles on the relationship between Type-II diabetes and obesity both note that weight gain around the trunk and waist line – the spare tire we noted in our section on the effects of cortisol on weight gain – appears to be strongly correlated with the emergence of Type-II diabetes. (Leong et al, 1999; Vague et al, 2008)

This is not surprising in light of the relationship between insulin resistance and Type-II diabetes. As we noted earlier, excess cortisol can make it harder for insulin to be delivered to muscles. When insulin delivery to the muscles is reduced, the muscles respond by issuing signals to the part of the body where insulin is produced – the pancreas – telling the pancreas to work harder to make more insulin available.

This has two important effects. It can cause the pancreas to work towards the point of exhaustion and breakdown, and can flood a person’s circulatory system with larger and larger amounts of insulin. Insulin receiving cells, in response to excess amounts of this chemical, begin to become resistant to insulin. This means they will need larger amounts of insulin in the future to perform necessary metabolic work, in the same way that receptor cells for addictive substances begin to require higher doses of the substances as dependence develops. This creates the metabolic combination that moves a person towards the development of Type-II diabetes.

Diabetes, in turn, contributes to the development of many other health problems, including cardiovascular disease – made worse by the health complications of obesity – as well as kidney problems that add further adverse effects to the cardiovascular problems associated with obesity and diabetes.


Cardiovascular Problems and Sleep

There are a number of contributing factors for cardiovascular problems related to insufficient sleep. Sleep has a modulating effect on the autonomic nervous system, so it reduces the demands placed on the heart and the cardiovascular system during any period where there is an extended sympathetic nervous system response when a person is under stress. (Wolk, et al.)

There are also changes in systemic hemodynamics depending upon whether a person is getting enough sleep, which is another way of saying the ease with which blood can move through a person’s veins and arteries. (Wolk, et al.) This factor is interactive between vasoconstriction and vasodilation, e.g., how the veins and arteries relax or tighten up, and factors related to the thickness and stickiness of the blood itself as it moves through the cardiovascular system. These interactive factors are both affected by whether a person is getting adequate or inadequate amounts of sleep. (Wolk, et al.)

Even how well the specific heart muscles function can be influenced by sleep, through complex chemical interactions occurring from the restorative factors during a good night’s sleep and the purposes of each of the sleep stages. (Wolk, et al.) It is also probable that there are beneficial effects of the body maintaining a regular and predictable passage through both the circadian and ultradian rhythms, both of which are directed by good sleep hygiene. 

Additionally, it must be remembered that there is a chain of connections linking cortisol elevation to increased migration of fat cells to a person’s waistline then to increased metabolic processes creating diabetes, as well as a concurrent accumulation of fatty deposits in a person’s cardiovascular system, a decreased capacity to metabolize blood sugar, and many other effects that can be destructive to a person’s heart health. (Vague) 

Moreover, the increase in overall inflammation that occurs in response to both sleep deprivation and the stress that accompanies it does not remain localized, but can be diffuse throughout a person’s body. The chemical messengers that trigger the inflammation response travel everywhere within a person’s bloodstream. There is accumulating evidence that a significant degree of the damage of coronary artery disease is the result of the inflammation processes occurring in the arterial walls. (Libby)

Because a good night’s sleep is restorative for both stress and for reductions in inflammatory responses, it is extremely beneficial for overall heart health and protective against heart disease, heart attacks and strokes. In short, there are substantial and profound reasons why a good night’s sleep is essential to the long term well being of a person’s heart health.


Suppression of the Immune System and Sleep

Sleep deprivation appears to decrease a person’s overall immune system functioning. (Rogers, et al., 2001) There appear to be several chemical mechanisms through which this occurs, including decreases in the release of certain proteins called cytokines (Mayo), decreases in the capacity to create antibodies to viruses and bacteria (Leproult & van Cauter), problems created for the functioning of certain kinds of white blood cells that destroy and digest foreign microorganisms responsible for many infections (Ackerman), and increases in inflammatory processes. (Yudkin et. al., 2004)

Scientists are still working to determine the exact mechanisms through which all of these immune system problems are created. However, some of the effects of sleep deprivation on the body are very similar to the effects of physical stress. (Ackerman) As we have noted previously in this course, it is not necessary for a mental health clinician to possess the same degree of knowledge as the scientists who are currently studying these issues at the molecular level, but it is helpful to be able to describe some degree of understanding of these matters to clients as we build a case for them to allocate more focus and attention on sleep hygiene.