What is insomnia?

Introduction

Insomnia is defined as the perception that a person’s sleep is inadequate or abnormal. The person with insomnia may report difficulty falling asleep, a short sleep time, frequent awakenings, and nonrestorative sleep. The daytime symptoms of insomnia include fatigue, excessive daytime sleepiness (EDS), mood changes, and impaired mental as well as physical functioning. Insomnia can be caused by conditions such as stress, anxiety, depression, substance abuse, medical illness, or other sleep disorders, but it may occur in some patients without any known underlying disorders. The occurrence of insomnia increases with age; one study estimates that approximately 50 percent of people between the ages of sixty-five and seventy-nine experience trouble sleeping. A 2004 study indicated that this is most likely related to the pain and discomfort associated with chronic disease. Treatment options such as the use of eszopiclone (Lunesta), zolpidem (Ambien), sedative-hypnotics, and behavioral interventions have been studied, each noting various degrees of success (although sedatives were found to sometimes increase adverse effects).

Types of Insomnia

TheAmerican Academy of Sleep Medicine (AASM) recognizes two general types of insomnia. Classified on the basis of the duration of the period in which the person experiences insomnia, these two types are transient insomnia and primary insomnia. Transient insomnia is seen when a person has had a history of normal sleep but experiences a period of insomnia that lasts less than three weeks; the patient returns to normal sleep after the insomnia period. The insomnia period is usually tied to a specific experience or situation, and it is believed that there are two common processes that are involved in transient insomnia. The first involves central nervous system arousal and any condition that may cause such arousal, whether it is psychological or environmental. There is no clear physiological disorder associated with this condition, but some research suggests that individuals who are likely to be aroused by stress may be more vulnerable to this type of insomnia than other people. Some sleep researchers indicate that emotional disturbance may play a role in up to 80 percent of transient insomnia cases.

A second process involved in transient insomnia results from people having a sleep-wake schedule that is not aligned with their own circadian (twenty-four-hour) rhythms. Biological rhythms control many bodily functions, such as blood pressure, body temperature, hormonal activity, and the menstrual cycle, as well as the sleep-wake cycle. Insomnia can be caused by a sleep-wake cycle that is misaligned with the circadian rhythm, such as that which occurs when people travel across many time zones or engage in shift work. Circadian rhythm disorders can last for periods of more than six months, in which case the problem would be considered chronic.

Primary insomnia is diagnosed when the patient’s insomnia is not secondary to problems such as depression, anxiety, pain, or some other sleep disorder, and it lasts for a period longer than three weeks. Two types of primary insomnia are persistent psychophysiological insomnia (PPI) and insomnia complaints without objective findings. PPI is commonly known as learned, or behavioral, insomnia, as it is caused or maintained by maladaptive learning—that is, by the occurrence of sleep-incompatible behaviors, such as caffeine intake before bedtime. PPI is diagnosed when the patient demonstrates sleep difficulties that are verified in a sleep laboratory and are then traced to their behavioral causes. Figures vary, but approximately 15 percent of those patients diagnosed as having insomnia probably have PPI. One common feature of PPI is excessive worrying about sleep problems. Great efforts are made to fall asleep at night, which are unsuccessful and lead to increased sleep difficulty; however, the patient may fall asleep quite easily when not trying to fall asleep.

Theories of Insomnia

One theory concerning how persistent psychophysiological insomnia can develop suggests that some people have a poor sleep-wake cycle, which makes it more difficult for them to overcome sleep-inhibiting behavior. For example, it is possible for people to become so anxious concerning their poor sleep that even the thought of their own bedrooms causes them stress, which further increases their sleep problems and creates a cycle of increasingly difficult sleep. This cycle would eventually end for persons with normal sleep cycles, but it is much easier for these events to disrupt those who already have the poor sleep-wake cycle suggested by this theory. Although PPI may begin in response to stress or an emotional situation, it should again be noted that in PPI this type of learning or behavior plays the major role in the insomnia complaint.

Most patients with insomnia will exhibit irregular sleep patterns or polysomnographic findings when tested in a sleep laboratory; however, there are those who complain of insomnia yet show no irregular sleep patterns. In the past, these people were viewed as having “pseudoinsomnia,” and they were sometimes suspected of complaining of poor sleep as an excuse for being lazy. Those who have insomnia complaints without objective findings do not show any physiological or psychological disorder and do not exhibit any sleep-incompatible behaviors, yet they commonly respond to treatment of their insomnia as would a verified insomnia patient.

One study found that insomnia was associated with anxiety, depression, psychiatric distress, and medical illness in 47 percent of the cases. The medical and psychiatric disorders, as well as the pharmacological substances, that can cause insomnia are extremely numerous. James Walsh and Roger Sugerman note three theories that attempt to explain the occurrence of insomnia in psychiatric disorders and that may prove helpful in understanding the process. The first suggests that insomnia results from a psychological disturbance that goes unresolved and leads to arousal that prevents sleep. The second states that neurochemical abnormalities may be the cause of insomnia in psychiatric disorders. The final theory asserts that affective (emotional) disorders may disturb the biological rhythms that control sleep.

Diagnosing Insomnia

The importance of a greater understanding of the mechanisms of sleep and insomnia can be appreciated by everyone. Everyone knows that when one feels sleepy, it is difficult to concentrate, perform simple tasks, or be patient with other people. If the sleep disorder is present in an individual over a protracted length of time, it can become virtually intolerable.

The general consensus developed from population-based studies as of 2014 is that approximately 30 percent of the adult population of the United States experience one or more symptoms of insomnia. However, the National Institute of Health found in 2005 that if diagnostic requirements included impaired functioning during the day as a result of the insomnia symptoms, this number declined to 10 percent. Still, many adults experience at least some difficulty sleeping in their lifetimes.

Insomnia may have drastic effects on behavior during the day. Fatigue, excessive daytime sleepiness, mood changes, and impaired mental and physical functioning are all frequently caused by insomnia. Difficulties in the workplace, as well as increased health problems, may also be associated with insomnia.

Diagnosis of insomnia depends on an accurate evaluation of the circumstances surrounding the complaint. The clinician must take many things into account when diagnosing each particular case, as insomnia may be the result of any number of factors in the patient’s life. Questions concerning behavior should be asked to determine if the insomnia is caused by sleep-incompatible behaviors. Polysomnographic testing in a sleep laboratory may be necessary to determine which type of insomnia the patient has.

Treatment Options

Once properly diagnosed, insomnia may be treated in a number of ways, all of which depend on the type of insomnia. The typical treatment for sleeping problems tends to be the prescription of sleeping pills. A 2005 study found that adults aged twenty to forty-four doubled their use of prescription sleep aids, while among adolescents aged ten to nineteen, the increase in usage was 85 percent between 2000 and 2004. The treatment of transient insomnia may involve small doses of a short-acting drug, including benzodiazepines such as diazepam (Valium) or lorazepam (Ativan); Z-drugs such as zaleplon (Sonata), zolpidem (Ambien), and zopiclone (eszopiclone analogue Lunesta); or nonbenzodiazepines, such as indiplon. Simply counseling or educating patients concerning situations that may increase their sleep problems is frequently found to be effective. If the transient insomnia is caused by disruptive sounds in the sleeping environment (such as snoring or traffic noise), devices that mask the noise may be used. Using earplugs and placing a fan in the room to mask the noise are two simple examples of this method. If the sleep disturbance is associated with misaligned circadian rhythms, the person’s bedtime may be systematically adjusted toward either an earlier or a later hour, depending on what time the individual normally goes to sleep. Strict adherence to the adjusted sleep-wake schedule is then necessary for the individual to remain on a regular schedule. This method is referred to as chronotherapy.

Peter Hauri suggests that treatment of persistent psychophysiological insomnia should typically involve aspects of three domains: sleep hygiene, behavioral treatment, and the use of hypnotics. Methods involving sleep hygiene focus on educating the patient concerning proper sleep habits. Hauri states that the goal is for the patient to avoid all stimulating or arousing thoughts. This is done by focusing on or engaging in monotonous or nonstimulating behaviors at bedtime such as reading or listening to pleasant music.

Behavioral methods include performing relaxation therapy, limiting sleep time to a few hours per night until the patient is able to use the time in bed as true sleeping time, and using stimulus control therapy. This method requires patients to get out of bed whenever they are not able to sleep. The process is aimed at reducing the association between the bedroom and the frustration with trying to go to sleep. Auricular acupuncture also has been found successful in the treatment of insomnia.

The use of hypnotic medications is indicated in patients who have such a need for sleep that they “try too hard” and thus become aroused by their efforts. In 2005, the Food and Drug Administration approved ramelteon (Rozerem) for the treatment of long-term insomnia. As with transient insomnia, a small dose of a short-acting drug is suggested to break this cycle of frustration.

The treatment for patients who exhibit no objective polysomnographic findings is similar to that for patients with any other type of insomnia. These patients also tend to respond to behavioral, educational, and pharmacological methods.

Sleep Research

The discovery of the methods used to monitor electrical activity in the human brain during the late 1920’s essentially ushered in the modern era of sleep research. With this development, sleep stages were discovered, which eventually led to a greater understanding of what takes place in both normal and abnormal sleep.

In Sleep: A Scientific Perspective (1988), A. Michael Anch, Carl P. Browman, Merrill M. Mitler, and James K. Walsh state that most insomnia research before 1980 treated insomniacs as one group, with little attention paid to differences such as duration of the disorder, causal factors, or the nature of certain study groups, such as the elderly, women, or ethnic minorities. Although specifying types of insomnia limits the ability to generalize findings, these authors note that the inclusion of different types of insomnia in studies eventually increased knowledge of the psychology of sleep and insomnia.

Much has been learned that allows doctors and psychologists to treat the different types of insomnia more effectively. The myth of the “cure-all” sleeping pill has been replaced with a more sophisticated approach, which includes educational and behavioral practices. Medications are still used, but treatment options have increased so that clinicians are not as limited in their choices.

As the study of sleep disorders has developed in terms of scientific sophistication, researchers have been able to learn the importance that sleep holds in day-to-day functioning. They have also discovered how detrimental sleep loss or disruption of the sleep-wake cycle can be. Aiding in the discoveries have been scientific developments in neurobiology, behavioral medicine, physiology, and psychiatry that allow analysis of the mechanisms in normal and abnormal sleep. It is hoped that as scientists gain a further understanding of insomnia through research, they will also understand, more generally, the true purpose of sleep.

Bibliography

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