Sleep and sleep disorder 2

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Healthy sleep volunteers exposed to the cold virus are statistically less likely to develop a cold compared to less healthy sleepers similarly exposed. While there are obviously other factors that have an effect on one's susceptibility to the cold virus, the protective effect of sleep is consistent. And the likely mechanism for this effect probably lies in the immune system.

All other considerations being equal, who is more likely to develop a common cold, a habitual good sleeper or a chronic poor sleeper? Explain your choice.

Good sleep promotes health, immune function, mood, vitality, and possibly longevity, while chronic sleep debt promotes precisely the opposite. Therefore, a safe drug to suspend all sleep seems unlikely for a long time to come, if ever.

Are there counter arguments against the potential use of an artificial stimulant to suspend sleep? In your opinion, what is the likelihood that a drug to safely suspend sleep will appear in your lifetime?

The most sensible way of dealing with this dangerous condition is to simply plan your life so that you never have to drive when drowsy. If, in spite of your best intentions, you find yourself driving when you are tired, do not attempt to rely on the old notions of rolling down the window, turning up the radio, singing, and the like. Studies have shown that coffee with a full dose of caffeine does help. However, a nap followed by a strong cup of coffee helps much more. If you find yourself driving and feeling drowsy, pull over! Now! No destination is more important than your life.

Assume you are driving by yourself late one night, and you find you are feeling drowsy. Is it a good idea to deal with the drowsiness by opening the car window and cranking up the volume on the radio? Are there any better strategies?

If you snore or show repeated leg kicks during the night, your spouse or sleeping partner may be able to tell you if you suffer a disorder such as sleep apnea or restless legs syndrome. Or, if you sleep alone, try using a tape recorder for a few hours over several nights in a row. As a rule, if you have problems with sleep apnea, the tape recording will tell you "loud and clear."

Assume you have a strong suspicion that you might be suffering from sleep apnea or restless legs syndrome. How would you go about confirming this hypothesis using home methods?

The widespread idea that one can be more productive by working long hours into the night and sleeping less and less simply does not work in the long run. Sleeping less serves to increase sleep debt, which in the long term disrupts and interferes with productivity.

Critique the following statement: "If I want to increase my productivity, all I have to do is gradually condition myself into the habit of sleeping less and less."

The prefix "para-" means "along with," or "at the same time as." Those with a parasomnia sleep normally, but other things happen at the same time. An easy example is sleep talking. As shown in appendix A of the textbook (pages 457-461), an exhaustive list of the parasomnias includes some behaviors that are somewhat rare and go beyond the scope of this course. However, there are several major groupings of the parasomnias that are helpful and interesting. These groupings are (1) arousal disorders, (2) sleep-wake transition disorders, (3) parasomnias associated with REM sleep, and (4) other parasomnias. Some of the parasomnias are more common in children, such as sleepwalking, night terrors, and bedwetting.

Define parasomnia. What are the major groups of parasomnias? What is the relationship of the parasomnias with age?

Transient insomnia is loosely defined as insomnia lasting up to two weeks, although it can range considerably above and below this amount. It accounts for an estimated three-fourths of all cases of insomnia, and therefore to say that this group is huge is no overstatement. Your textbook lists three causes of transient insomnia: hyperarousal, jet lag and schedule changes, and poor sleep environment. Of these three causes, hyperarousal is likely to be the culprit at least half of the time.

Define transient insomnia. What is the most frequent cause of transient insomnia?

Numerous approaches to treating apnea have been introduced and evaluated. Many of these treatments have had a short life, fortunately, whereas others have stood the test of time. The most successful to date is continuous positive airway pressure (CPAP). In this condition, the victim wears a small face mask (covering the mouth and nose) and air from an innocuous pump is thrust through the tubing to the mask at a continuous rate all night. The air pressure to the face mask is sufficient to keep the upper airway passage open, thereby preventing the obstructive episodes. Although the procedure requires a certain period of adjustment, the general feeling among reporting victims is that the improvement in daytime alertness is well worth the effort. Variations on the CPAP procedure have also been introduced, which in some cases can be used in the treatment of central apnea.

Describe the CPAP procedure. What does the commentary state about its effectiveness?

The immune system consists of a loosely defined collection of organs, tissues, and processes that protects the body from external invaders, such as bacteria, viruses, and the like. It includes the lymphatic system, which includes a highly effective array of white blood cells (lymphocytes) that arise in bone marrow, plus the thymus, tonsils, and spleen. Research in recent years has indicated that lifestyle can have marked effects on immune function. In particular, stress has been shown to have significant disruptive effects on immune function. Sleep researchers are generally convinced that poor sleep is itself a stressful condition, which increases the risk of immune system deficiency, which in turn places the individual at risk for numerous harmful, compromising effects.

Describe the basic components of the immune system. Summarize the relationship between sleep, stress, and immune function.

There are a number of behavioral approaches to treating primary insomnias: Improving sleep hygiene. This is discussed in detail in Lesson 9, and it can be quite effective in many cases. It consists of following a set of reasonable rules, such as setting a regular sleep/wake schedule, avoiding caffeine, as well as taking other positive steps. Relaxation techniques. Relaxation training has long been known to help in dealing with hyperarousal, and so it is a reasonable alternative for treating primary insomnias. Stimulus control. This consists of avoiding upsets at bedtime, an obvious part of good sleep hygiene anyway. Cognitive techniques. This includes late-night reading (an old habit of mine), and old ideas such as counting sheep. Alternative therapies. There are many techniques discussed in your textbook at this point, some with attractive potential (such as massage), and others of more dubious value (such as acupuncture, hypnosis, and herbal remedies). Beyond a possible placebo effect, some of these alternatives should be viewed with healthy skepticism.

Describe the behavioral approaches to treating primary insomnia.

Your textbook provides a simple form (page 336) that you can use to keep a sleep diary, a procedure used in sleep laboratories and sleep clinics for many years. If at all possible, we highly recommend that you try this for at least one seven-day week, preferably more, provided that your schedule, health, and so on are reasonably close to average for you. After you have maintained your diary for at least a week, you can calculate how much you slept each day, as well as your daily average for the week. Many people honestly believe that they can get by with five to six hours per night, because they often get that much on week nights. However, when they take all naps into account and also average in the longer sleep sessions on weekends, they are surprised to learn that their daily average is actually closer to eight hours than they previously believed. This is an excellent demonstration of the reasons for using objective measures, rather than subjective opinion. Next, by rating your degree of alertness periodically every day, you can begin to see your own daily peaks and valleys, which you can use to good advantage in making scheduling decisions in the future. Do not be overly concerned if the peaks and valleys in your degree of alertness/sleepiness seem erratic or distinctly different from the earlier descriptions in this course. Remember, much of what we describe as "average" or "normal" in the realm of sleep is based on observations made over very long periods, sometimes even years, in order to see normal peaks and valleys. This is a major reason for maintaining your sleep diary for as many weeks as possible.

Describe the procedure for keeping a sleep diary. What are the benefits and limitations of keeping a diary of your sleep? Is it enough to do this for one week, or should you do it for a longer time?

Sleep scientists have speculated for many years that REM sleep might provide some form of support for cognitive function and long-term memory storage and/or help us discard useless memories, thereby freeing up space for more important memories. For various reasons outlined in your textbook, these are very intriguing ideas, and might help us answer the basic question (as yet unanswered) as to the purpose of REM sleep in the first place. Unfortunately, most of the evidence in support of the role of REM sleep in learning and memory is correlational, that is, a cause-and-effect relationship is inferred simply because two events happen at about the same time. This is not good scientific thinking, since there is still the possibility that the two events were caused by a third unmeasured variable. Both REM sleep and memory activity may be the product of activity in the same (or closely associated) brain structures, an untested but plausible alternative hypothesis.

Describe the scientific evidence that REM sleep promotes cognitive function and memory.

Behavior disorders are frequently associated with persistent insomnia. One frequent example is depression, the incidence of which is quite high nationally. Curiously, there is no single depressed sleep pattern—some report typical insomnia and some literally escape into sleep. The same is likely to occur with any behavior disorder characterized by excessive energy and/or inner turmoil, such as post traumatic stress disorder (PTSD), attention deficit hyperactivity disorder (ADHD), childhood autism, anxiety disorder, bipolar disorder, schizophrenia, drug and alcohol abuse, and others. Here too, treatment of the persistent insomnia depends largely on successful treatment of the behavior disorder.

Explain how behavioral and emotional disorders can produce persistent insomnia. Give examples.

Much anecdotal evidence exists on this phenomenon, and most of us have heard the stories of important scientific discoveries made in the dreams of some scientist. The question remains as to how often this occurs, and is there anything that we can do to harness the process for our advantage? Until that happens, I suspect that we shall have to be content to puzzle and speculate about these curious experiences.

Have there been anecdotal reports about the relationship between REM dreams and scientific discoveries? Based on the readings, do you think it is a good idea to rely on your dreams to help you solve a complicated problem?

There seems to be little doubt that insomnia, in one form or another, is far and away the most common sleep complaint. Estimates range into the millions affected at any one time, but, safe to say, it likely affects all of us sooner or later. Sleep scientists have known for a long time that sleep is a very fragile process. Just about everything has to be right in order to see the progression of sleep stages in the normal ninety-minute cycle. Disturb any of the many important requirements, and poor sleep ensues. That is why insomnia is not a disorder. It is a symptom, just as fever or headache is a symptom, with many possible causes.

How common is insomnia in society, in general? Is it a symptom or a disorder?

Either form of delayed sleep phase syndrome (lark or owl) could lead to apparent persistent insomnia. Those with DSPS have persistent difficulty getting to sleep at the start of the night, and those with ASPS persistently awaken too early in the morning.

How do DSPS and ASPS lead to persistent insomnia?

Several examples of sleep disorders that produce persistent insomnia are restless legs syndrome, central apnea, and sleep state misperception, all of which disrupt sleep and/or are associated with persistent complaints of poor sleep. Any sleep disorder that produces a restless or disrupted pattern at night is likely to produce persistent insomnia.

How is it that other sleep disorders may produce persistent insomnia?

It seems likely that the clock-dependent alerting function of the biological clock is accomplished through the brain's primary arousal system, the reticular activating system (RAS) located in the brain stem. Stimulation of the RAS produces an increase in excitatory neurochemicals or neurotransmitters, notably norepinephrine, dopamine, acetylcholine, and serotonin. These excitatory neurochemicals in turn interface closely with the pleasure centers in the limbic system, and one theory at this time is that these neurotransmitters are restored by sleep.

How is the clock-dependent alerting function of the biological clock accomplished? What brain mechanism is believed to be responsible? Include the role of neurochemicals, if any.

Sleep scientists have learned the answers to many of the most puzzling questions about sleep, and also made a number of important discoveries in the process. The most important news, however, is that there are many valuable benefits from a lifetime of healthy sleep. On the other hand, the bad news is that many of the most important questions about sleep remain unanswered at this time, but the worst of it is that a lifetime of poor sleep has many dire consequences.

How many of the most important questions about sleep have been answered? A few? Many? All? Pick one of the questions that has been answered and explain the reasons(s) for your choice.

Dreams seem to come from outer space (or perhaps from our deepest and darkest inner self) without any forethought or planning on our part, and often involving the most bizarre characters and plot situations. They are, after all, involuntary visual hallucinations, unlike any experience that we have when we are awake. Oftentimes there is a strong emotional component. Some dreams are very pleasant, but often as not, they can be upsetting or at least worrisome.

How would you describe a dream to someone (from another planet) who has never had the experience?

Probably the truth lies somewhere in between Freud and Hobson. Clearly Freud went too far. Remember, REM sleep was discovered about half a century after Freud. He assumed that dreams were signal events that occurred once every week or two, not every ninety minutes! On the other hand, most of us can recall dreams that did make sense, that did seem to communicate a message. How about the example of a wife who has a dream of worry about her husband's health? Or a husband dreaming about his wife's health? Or a parent dreaming about a child? Sometimes, our dreams seem to have almost direct meaning, requiring little or no expertise to interpret. After all, it makes sense that we sometimes dream about the questions that concern us most, just as we mull over these concerns when we are fully awake. And so it would seem that while dreams do not shed light on unique hidden information available through no other means, neither are they always random and meaningless as well. Probably a very small number of our dreams are memorable, but the vast majority are eminently forgettable. One sleep scientist collected a large number of REM dream reports, and he found that the average REM dream report is actually quite boring. A typical report was something like the following: "I dreamt I was sitting in a room I'd never seen before, and a man I do not know walked by without saying anything." No doubt Freud would find some hidden meaning in such a report, but the counterargument might be "How do we know if the so-called hidden meaning is correct, and is it worth the effort to find out?"

How would you reconcile these two views of dreaming?

As a rule, studies have shown that a healthy diet and regular exercise promote good sleep. There are only a few notes of caution. One, large dinner meals should be finished at least three to four hours before bedtime, although a small bedtime snack (such as milk and cookies) is usually all right. Second, note that any exercise should be regular. There is little doubt that an aerobic fitness program maintained over a period of months and years promotes healthy sleep; however, a one-time bout of strenuous physical exertion in the evening can disrupt sleep significantly.

Is it true that all nutritious meals and all exercise promote good sleep? What are the exceptions? Exceptions aside, do a healthy diet and exercise usually promote healthy sleep or not?

Persistent insomnia is largely due to secondary causes, including medical conditions, DSPS and ASPS, emotional and behavioral issues, as well as other sleep disorders.

Is persistent insomnia likely to be due to some secondary cause? If so, what are the secondary causes of persistent insomnia?

Perhaps the most common sleep-wake transition disorder is sleep starts. These are sudden total body jerks experienced by most people just as they are falling asleep. Apparently this symptom can appear at any age and is regarded as benign, unless associated with other sleep symptoms.

Name and describe a sleep-wake transition parasomnia.

Sleepwalking and night terrors are arousal disorders. Sleepwalking can include a variety of behaviors, such as walking or eating, usually in a notably disorganized manner. It is most commonly found in children ages five to fifteen years. It occurs in stage 3-4 sleep (not REM), and the person has no memory of the events in the morning. Night terrors are also associated with stage 3-4 sleep, and there is no recall in the morning. They most commonly occur in boys, ages five to eight years. Both sleepwalking and night terrors are much less common in adults.

Name and describe two arousal disorder parasomnias.

Nightmares and sleep paralysis are parasomnias associated with REM sleep. A nightmare is any unpleasant REM dream. In contrast to night terrors, nightmares can occur at any age, occur in REM sleep, and there is recall in the morning. Sleep paralysis is a complete loss of voluntary muscle function, generally lasting a few minutes. There is some evidence that sleep paralysis runs in families, and it may appear in childhood, or develop in adulthood.

Name and describe two parasomnias associated with REM sleep.

Bruxism and bedwetting are included in the "other parasomnias" category. Bruxism is a pattern of teeth grinding during sleep. The force may be strong enough to grind the teeth down to the gums, and it is often treated by dentists with a rubber mouth guard worn during sleep. It is somewhat more common in females and can occur at almost any age beginning with childhood. While there is some disagreement among experts, at least some bruxism seems to be stress-induced. Bedwetting is a symptom with a genetic basis, more common in boys, and rare after ages twelve to fourteen years.

Name and describe two parasomnias in the "other" group of parasomnias.

Because of Freud's worldwide impact, his book The Interpretation of Dreams should be required reading for any educated person. He described dreams as "the royal road to the unconscious," implying that certain critical insights into one's inner self could be attained only via this route. To his credit, Freud's thinking held sway for many decades throughout the twentieth century. Not only was his work highly creative and original, but it also seemed to promise the solution to many neurotic symptoms of the day. However, now in the twenty-first century, the enthusiasm for Freud's approach has declined considerably. Most sleep scientists today discount Freud's thinking, for the most part. No doubt there are psychiatrists who still insist that Freud's work was essentially valid; however, there is scant research in support of that position.

Summarize Freud's thinking about the interpretation and significance of dreams.

Each of the following guidelines consists of behaviors that you can control, and therefore they constitute a behavior control program for better sleep: The bed and bedroom should be used for sleep and sex and nothing else. No long drawn-out phone conversations, late night reading, snacking, office work, homework, etc. Avoid all naps—but only if you have trouble sleeping at night. On the other hand, if you are carrying a large sleep debt, then naps might be a good idea. Set a regular wake-up time and try your best to stick to it seven days a week. Do not play catch-up on weekends. If you find that you are still awake fifteen to twenty minutes after going to bed, get up and do something else, such as read a book. Avoid all stimulants, such as coffee, tea, or soda with caffeine in the evening. Avoid all alcohol. Avoid big meals within three to four hours of bedtime. Avoid unusual strenuous exercise in the evening. However, an aerobic exercise program practiced on a long-term regular basis is generally beneficial. Turn off the TV, radio, or stereo. Make sure the bedroom conditions are optimal—optimal temperature, comfortable sheets, blankets, etc.

Summarize the behavioral control steps that one can take to deal with transient insomnia.

The typical sequence goes something like the following: (1) on average, being sick (flu or fever, for example) often leads to an increased desire for sleep; (2) the ensuing sleep then has the effect of promoting the function of the immune system; and (3) a well-organized immune system in turn promotes the return to health. Unfortunately, the opposite is also true. Chronic sleep deprivation, that is, accumulation of a large sleep debt over an extended period of time, disrupts or impairs immune system function, placing the person at risk for future infectious diseases, in addition to the direct physical, mental, and emotional effects of sleep debt.

Summarize the common relationship between illness, sleep, and a return to health. Can this process work in more than one direction?

Caffeine and alcohol both have marked effects on sleep, though they are quite different. Caffeine is a stimulant that should be avoided by most people in the evening, perhaps as much as three to five hours before normal bedtime. In order to do this successfully, it is also necessary to learn which products have caffeine. Coffee and tea are notorious caffeine carriers; however, decaffeinated coffee and herbal tea have very little caffeine. The situation with soft drinks is much more complicated, and the best solution is to become a habitual label-reader. The only way to know for sure whether you are getting caffeine is to read the label. Alcohol has many effects that are the opposite of caffeine. Alcohol initially promotes sleep onset, but, taken in average amounts, it is metabolized out of the blood stream in three to five hours, so that the individual awakens in the middle of the night, unable to get back to sleep. As a rule, therefore, individuals with serious sleep issues should avoid alcohol in the evening, or at least limit their intake to one drink. At the other extreme, studies have shown that long-term alcohol abusers have many sleep problems, beyond their numerous difficulties in other areas.

Summarize the effects of caffeine and alcohol on sleep.

Melatonin is a hormone secreted by the pineal gland located near the suprachiasmatic nucleus, the site of the biological clock. Research has indicated that melatonin appears to have an effect on the setting of the biological clock. It is found at higher levels at normal bedtime, and lower levels during the day. Curiously, it is also found at higher levels in the winter and lower levels during the summer months. Since melatonin is a natural substance, it is available on the same shelves as other food additives, such as vitamin supplements, in your local grocery or health food store. Because it is readily available, there is no doubt that many people have experimented with this substance as a sleep aid in recent years. Yet very little is known about the long-term helpful and harmful effects of taking melatonin for an extended period of years. Your textbook suggests that temporary low-level use of melatonin may be advisable at times, however, long-term use is risky at best. Certainly any use of a chemical substance for long-term assistance likely creates as many or even more problems than it solves, with the exception of certain chronic physical diseases.

Summarize the effects of melatonin. What is the mechanism for its effects? Is it a recommended sleep aid?

The incidence of narcolepsy is not high, about one in every two thousand people worldwide. The symptoms are likely to appear in the young adult years, and the typical victim is probably over age twenty when the diagnosis is made. There is good evidence that the disorder has a genetic basis, and the particular combination of symptoms suggests that there may be a neurological defect in the brain center controlling REM sleep, although this has yet to be established. Narcolepsy is a chronic disorder, and thus far about the only form of treatment has been medication. Many victims receive Ritalin or amphetamine, both with stimulant effects, with some apparent success over the long term. It should be noted however, that Ritalin is the medication often used in treating attention deficit hyperactivity disorder (ADHD) in children, an approach that has been criticized by some.

Summarize the incidence of narcolepsy. What are the possible causes? How is it most often treated, and with what kind of success?

The incidence of sleep apnea appears to be quite high. About 40 percent of the population has some form of the disorder, and half of them (20 percent of the population, or about fifty million cases in this country) are clinically significant. The high incidence of hypertension means that they are at serious risk for cardiovascular disease and attendant complications, not only during sleep, but also in the daytime hours. In your textbook, it is estimated that nearly forty thousand fatal heart attacks and strokes occur each year in the United States due to sleep apnea.

Summarize the incidence of sleep apnea. Is it a rare disorder? Is there any relationship between apnea and heart attack and stroke? Why?

The basic procedure for estimating your sleep debt is to use a home variation of the Multiple Sleep Latency Test (MSLT). To do this at home, simply lie down, preferably on your bed, and with the intention of going to sleep, but while also holding a spoon between your thumb and forefinger, with the spoon positioned directly above a plastic plate. When you go to sleep, the spoon will fall to the plate with a noisy sound, allowing you to wake up and check how long (in minutes) it took. As an alternative, ask someone (whom you know and trust) to observe you and watch for signs of regular breathing or light snoring. The observer records the number of minutes to sleep onset. Whichever method you choose, do it two or three times a day, preferably in the late morning or during the afternoon before your normal dinner hour. Then take the average number of minutes per trial for each day, and lastly figure the average over days. Use the table on page 342 to determine if your sleep debt is small, moderate, large, or severe. Your daily sleep need is another measure that can be estimated with home-based methods. The simplest method is to begin by setting a regular sleep schedule that you believe will be close to your true sleep need, for example, eight hours. Do this for a few days, then measure your MSLT with the spoon method, preferably during the afternoon dip in alertness. If you fall asleep quickly in the MSLT trials, you should increase your sleep schedule for a few days, for example to 8.5 hours, then re-test your MSLT latency, and keep increasing the amount of sleep until the MSLT latency consistently indicates small or moderate sleep debt. After a period of trial and error, you should have a fair idea of how much sleep debt you carry with various amounts of sleep.

Summarize the possible procedures that you might use to estimate your sleep debt and daily sleep need.

A major point here is that creativity takes, among other things, focused effort or motivation. Sleep debt, on the other hand, is clearly the enemy of motivation, and thus it follows that creativity is impaired under conditions of sleep debt.

Summarize the relationship between creativity, sleep, and sleep debt.

Experimental psychologists have shown that students who get a good night's sleep after studying for an exam remember the exam material better in the morning, compared to students who "pulled an all-nighter." Last minute late-night cramming for exams is simply not a good idea. In a similar vein, healthy sleep habits in general promote better learning. The example in your textbook of the student who had significant sleep debt and had great difficulty staying awake in classes is typical of the penalty that we pay for trying to squeeze too many hours out of a day. This was one of the major points emphasized in Lesson 2.

Summarize the relationship between healthy sleep and learning, such as studying for an exam.

Longevity is a product of many factors, such as family history, gender, nutritional and exercise habits, and use of tobacco and alcohol, to name but a few. However, the research seems to provide highly suggestive, but not conclusive, evidence that healthy sleep also promotes longer life. The reason for this ambiguous state of affairs is that the perfect study of the question would be very difficult. It would require a very large sample (thousands) of volunteers whose sleep and other habits would be monitored by totally objective methods over a period of decades. Such a project would cost many millions of dollars and would require objective methods that are not fully validated at this time.

Summarize the research on the relationship between sleep and longevity. Is it established that sleep promotes longevity? Explain your answer.

There can be little doubt that one of the most electrifying moments in the history of sleep research occurred when it was reported by Dement and Kleitman that dream reports occur about 90 percent of the time from REM awakenings. Given the wide preexisting interest in dreaming, the REM-dreaming report captured the imagination of many investigators. Here for the first time was an objective indicator (easily recorded eye movements) to measure the presence or absence of dreaming. And, wonder of wonders, dreaming apparently occurs every ninety minutes every night. Nobody (not Freud, not Dement, not Kleitman—no one) anticipated such a startling discovery. And of course, given the apparent hallucinatory quality of dreams, speculation raged over the possible relationship between REM sleep and schizophrenia, a behavior disorder in which hallucinations are not uncommon. Dreams can occur in both REM and non-REM sleep, although something like 80-90 percent of dreaming occurs in REM sleep, and therefore some writers in the field use the terms "REM sleep" and "dreaming sleep" interchangeably, as if they were synonymous. Strictly speaking, however, this is not correct, since some dream reports can be observed on non-REM awakenings.

Summarize the significance of the discovery of REM sleep and that dreams occur during REM periods. Do dreams only occur during REM sleep?

Your textbook lists two medical conditions that are frequently associated with persistent insomnia, namely, gastric reflux disease and fibromyalgia. These are merely two of the most common examples; however, many other physical diseases and injuries could be included here. For example, arthritis, spinal disk injuries, or any disease/injury associated with pain and discomfort could have a long-term disruptive effect on sleep. In all cases, treatment of the insomnia depends largely on successful treatment of the disease or injury.

What are some examples of persistent insomnia due to medical conditions? Can you add to those given in the text?

Unfortunately, there are a number of reasons why the majority of sufferers of sleep disorders never seek professional assistance. Listed below are the primary reasons for this: Men in particular have a reluctance to seeking help in general. Most people fail to see the importance of fatigue as a primary symptom. Most of us rarely witness our own sleep and are often poor reporters. Many persons fear that they will be seen as weak or neurotic if they complain of fatigue.

What are some of the reasons why the majority of individuals with a sleep disorder never seek professional assistance?

There are many over-the-counter (OTC) sleep aids, a strong indicator of their popularity. Some contain an aspirin supplement, and others contain an antihistamine known to produce drowsiness. These sleep aids have been shown to be safe when used as instructed; however, they also have little direct effect on sleep. Even an antihistamine-produced drowsiness does not lead to better normal sleep. Quite likely, the main result the OTC sleep aids have is a significant placebo effect. However, when one recalls that the most common sleep disorder (by far) is transient insomnia due to hyperarousal, then perhaps it is good that there is a readily available source of apparent (that is, placebo-enhanced) relief. Your textbook argues that the great use of OTC sleep aids is a strong indicator of the underuse of prescription sedatives, an idea with which some might honestly and vigorously disagree.

What are the OTC sleep medications? What are the arguments for and against the use of these sleep aids?

Jet lag occurs whenever we travel rapidly across a number of time zones—the more time zones, the greater the lag effect. We experience jet lag only when we travel east or west, but not north or south within one time zone. A jet trip from Chicago to Rio would not produce jet lag, but Chicago to Baghdad very likely would produce jet lag.

What are the conditions that produce jet lag? If you took a jet flight this afternoon from Chicago to Rio de Janeiro, would you be likely to experience jet lag? How about a jet flight from Chicago to Baghdad?

There are a number of physiological changes that occur uniquely during REM sleep, but not during sleep stages 2-4. Here is a convenient summary: REM sleep is accompanied by an almost total loss of voluntary muscle tone. Therefore it is physically impossible to sleepwalk during REM sleep, contrary to old notions about sleepwalking being an enactment of a dream. It also suggests that the peculiar symptom of sleep paralysis, a parasomnia where one is temporarily unable to move, may be some kind of physical extension of the loss of muscle tone in REM sleep. Contrary to common belief, REM activity does not occur continuously throughout a period of REM sleep. Eye movements come and go in bursts, commonly about four to six seconds. That is, during REM sleep, eye movements may be observed for about four to six seconds, followed by a period of no eye activity for another four to six seconds, followed by four to six seconds of eye movement, etc. Therefore, one can talk about bursts of REM activity that come and go during a single period of REM sleep. There are a number of changes in the autonomic (automatic emotional) nervous system during REM sleep. Two of the most observable changes occur in heart rate and respiration. Heart rate becomes notably more variable, showing a greater range of peaks and valleys compared to sleep stages 2-4 or wakefulness. That is, the highs are somewhat higher, but the lows are also lower, and consequently the average heart rate per unit time is actually unchanged—only the variability is increased. Not all sleepers show this heart rate variability in REM sleep. Depth/shallowness of respiration becomes more variable in REM sleep. During a four- to six-second burst of REM activity, respiration becomes very shallow for several inspiration/expiration cycles, almost to the point where the investigator can determine that REM activity is occurring simply by watching the flattened respiration recording before even looking at the eye movement channel. In contrast, respiration typically becomes deeper between the four- to six-second bursts of REM activity. The genitals show important changes in REM sleep. In healthy males, penile erections accompany every REM period. Similarly, adult females show increased vaginal blood flow during REM sleep. Initially, it was hypothesized that these vascular changes in men and women were a reflection of sexual content of REM dreams; however, there is no evidence that this is the case. In fact, the current thinking is that REM vascular activity has nothing to do with sexual content.

What are the primary physiological changes that occur during REM sleep?

Persons with narcolepsy show so-called sleep attacks. They may fall asleep quite suddenly at any time, any place, and in any posture. There are several symptoms in this condition, most of which tend to occur at the same time: vivid hypnagogic hallucinations with REM onset sleep cataplexy—sudden muscle weakness sleep attacks significant daytime sleepiness

What are the primary symptoms of narcolepsy?

Workers in certain industries commonly work a swing shift work schedule. That is, the work day is divided into three eight-hour shifts (day, evening, and night or "graveyard"), and workers change shifts every seven days, or once a week. Studies have shown that most swing shift workers never fully adjust to this arduous schedule, and consequently they carry a very large sleep debt for extended periods. Assuming that the phenomenon of swing shifts is not going to go away, it seems wise to figure out how to make the best of it. Studies have shown that there is a genuine advantage if the shift swings are every three weeks and in the clockwise direction; that is, day to evening, evening to night, and night to day, rather than the opposite. Under these three-week clockwise shift conditions, worker morale and productivity improved significantly.

What are the sleep-related difficulties produced by swing shift work? What is the best way to minimize these sleep difficulties?

There are various strategies for dealing with jet lag. One of the simplest is to arrive at your destination several days early, so that you are more-or-less adjusted in time for your important meeting or conference. Many world diplomats, because of their frequent long-distance travels, routinely use this strategy effectively. Another solution is to reset your biological clock, starting two to four days before your trip. There are several components that can help you do this. One strategy is to use bright light during the corresponding hours of peak alertness at your destination, followed by lowered light levels during dips in alertness, starting several days before the trip. Another is to take melatonin at your destination bedtime. And finally, you can adjust your bedtime gradually to match your destination bedtime, preferably in two-hour steps (earlier or later, depending on your direction of travel) per day for several days until you are going to bed at your destination bedtime. Ideally, with such a program, you should experience little or no jet lag at all.

What are the strategies that you might use to prevent or minimize jet lag if you have a big trip scheduled in the near future?

There have been three groups of prescription sleep medications in the United States in the last hundred years: the barbiturates, the benzodiazepines, and the imidazopyridines. The barbiturate secobarbital (Seconal) is well known to produce numerous undesirable side effects, mainly habituation, potentiation, hangover, addictive, and withdrawal effects; these side effects can occasionally be fatal. The benzodiazepine triazolam (Halcion) was among the most prescribed in the United States in the recent past. It is not as long-acting as secobarbital and potentiation effects are minimal, compared to the barbiturates. Nevertheless, the risk of addictive and withdrawal effects does remain, plus there are inconsistent reports of alarming side effects, such as increased risk of suicide. The imidazopyridine zolpidem (Ambien) is claimed to be the safest sedative to date, but it is not a cure-all. For example, an extensive listing of the side effects of zolpidem (Ambien), including increased tolerance (habituation), dependence (addiction), and harmful interactions with other drugs, including alcohol, is available on websites such as Healthtouch Online.

What are the three groups of sedative hypnotic sleep medications? Give examples of a sedative in each group, including common side effects.

Primary insomnia is insomnia with no other associated disorder or secondary condition. Your textbook describes two forms of primary insomnia: psychophysiological insomnia and idiopathic insomnia.

What are the two forms of primary insomnia?

There have been numerous efforts to find a stimulating elixir that can be safely used to produce true excitatory effects, without harmful addictive or other side effects. This list has included cocaine, amphetamine, caffeine, nicotine, dopamine, and others. And yet, in spite of intense interest over many years, each small measure of success has been illusory at best. Any short-term gains are far outweighed by long-term harmful effects.

What efforts have been made to identify a safe artificial stimulant? Name some of the substances that have been investigated. In general, what has been the result of these investigations?

Your textbook raises provocative questions about the possible use of modafinil to suspend the need for sleep. Many sleep experts consider such a view as not only unsubstantiated, but bordering on reckless, because it encourages a direction of experimentation with serious potential for harmful effects. It is logically inconsistent to express great concern over the virtual pandemic of sleep debt that exists nationally, on the one hand, and yet to encourage efforts to forego sleep entirely, on the other hand.

What hypotheses have been suggested about a potential artificial substance to suspend the need for sleep? What scientific evidence is there to indicate that such a use might be feasible?

In so-called lucid dreams the dreamer recognizes that the dream is taking place and consciously influences the flow of events. This is probably a relatively rare but, according to your textbook, learnable skill. Individuals get better with effort and practice. The scientific or problem-solving significance of this skill remains unclear.

What is a lucid dream? Is this a common experience? Does it help solve problems?

If transient insomnia is that lasting up to two weeks, then persistent insomnia is that lasting more than two weeks. However, this is an arbitrary distinction at best, since, as we will see, many of the cases of persistent insomnia are secondary to a diagnosed medical or behavioral disorder not encountered with transient insomnia.

What is persistent insomnia? How does it differ from transient insomnia?

The alternative to Freud's view was probably best expressed by Allan Hobson, a sleep scientist who found that there are certain brain signals that occur in bursts during REM sleep in all animals (including humans), and that this burst of activity apparently gives rise to random, meaningless cortical brain activity that we perceive as dreaming. In other words, dream content is random activity and reveals no deeply repressed ideas or motivations. In fact, this view suggests that Freudian interpretation of dreams is not only invalid, but also potentially misleading, even harmful. Certainly, the random nature of the brain signals is compatible with our common sense observations that dreams seem to come from nowhere, with many logical and perceptual discontinuities and bizarre distortions. In other words, many dreams do indeed seem quite random rather than purposeful.

What is the alternative view to Freud on the subject of dream interpretation?

Sleep apnea refers to a condition wherein the victim literally stops breathing for periods up to one minute during sleep. These breathless episodes may be repeated as often as twenty times per hour all night long! The victims are usually world class snorers, meaning that their snoring is unusually loud and can be heard by anyone remotely close to the victim's bedroom. Victims of sleep apnea complain of severe daytime sleepiness. Their daytime fatigue is both massive and pervasive; it significantly affects all aspects of their lives. For years and years they are at risk for dozing at the wrong time, such as when driving. Moreover, their overall efficiency, productivity, and freedom from error are well below the optimum. They routinely go to sleep in a mere few minutes when given the Multiple Sleep Latency Test, a true indicator of daytime sleepiness, only to be awakened shortly by their snoring and gasping for breath. There is at least one other symptom that is common in sleep apnea: high blood pressure. Victims frequently show serious hypertension.

What is the definition of apnea? What are the most common symptoms of sleep apnea? What is the relationship between apnea and snoring? Why?

There are two forms of sleep apnea: obstructive sleep apnea and central sleep apnea. Obstructive sleep apnea, by far the more common form, is due to an obstruction in the upper airway passage, which explains the relationship between apnea and snoring. Major contributing factors in causing the airway obstruction are buildups of fatty deposits, loss of airway muscle tone due to aging, and swollen tonsils and adenoids. The mere presence of snoring does not mean that the person has apnea; however it does indicate that the person's breathing is impaired and that the airway is nearly obstructed. Clinical apnea is a definite possibility in the future. Central apnea, much less common than the obstructive form, is due to a defect in the central neural mechanisms that regulate the breathing reflex during sleep.

What is the difference between obstructive sleep apnea and central sleep apnea? Which is more common?

Numerous studies have shown that sleep deprivation leads to decreased happiness, increased stress, and increased grumpiness. Good sleep, in contrast, leads to an increase in positive mood. The extent of these findings is rather striking. That is, sleep deprivation seems to have a greater effect on negative mood than it does on cognitive or performance measures.

What is the effect of poor sleep on mood? What is the relationship between good sleep and mood? How does the effect of sleep on mood compare to the effect on cognitive function and performance?

Sleep scientists discovered years ago that secretion of pituitary growth hormone increases during the night. Intuitively, this seems like a very practical arrangement, because it means that children experience most of their growth while they are at rest during the night. Repair of tissue damage also occurs at night for the most part. Laboratory studies have shown that growth hormone promotes sleepiness in lower animals, and so one can make a persuasive case that (a) sleep promotes tissue growth and improved immune function, but also that (b) tissue growth and improved immune function promote sleep! Both sequences of events can be true at the same time.

What is the effect of sleep on tissue growth and repair? Can the opposite occur, namely, can tissue growth and repair affect sleep?

Sleep apnea is age-related. While it can be seen at almost any age, the incidence increases with age. Sleep apnea in newborns was once considered a cause for sudden infant death syndrome (SIDS); however, this has now been largely discounted. Apnea in childhood does occur, though it is uncommon. With increasing age, so does the incidence of apnea increase, with the likely peak in the elderly, at about age seventy.

What is the relationship between incidence of sleep apnea and age?

If your schedule permits, naps can often be a big help in reducing sleep debt or helping you feel refreshed to meet some new challenge. Generally, naps near the afternoon dip in alertness are best. Naps in the evening are less helpful, but perhaps better than not napping at all. Adolescents and young adults with Delayed Sleep Phase Syndrome should definitely consider regular napping, preferably in the afternoon. On the other hand, if your sleep problem is insomnia due to hyperarousal, the most common form of insomnia, then naps are probably not a good idea. This is because an afternoon nap that is refreshing will likely cause you to feel less fatigued at your normal bedtime. And if you already have difficulty going to sleep at your bedtime, then any nap will only intensify the problem.

When are naps a good idea? When are they not such a good idea?

The true source of vitality is the biological clock through the process of clock-dependent alerting. This is an important point, because, after a good night of sleep, most of us expect some improvement in our feelings and behavior. Remember, however, that it is the process of clock-dependent alerting, driven by the biological clock, that is responsible for periods of energy and vitality. And this is equally true of both larks and owls.

Which of the following is true? (A) Good sleep promotes vitality; or (B) Clock-dependent alerting promotes vitality. Explain your choice. Is this equally true of larks and owls?


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