What are Sleep Disorders?

Sleep disorders (or sleep-wake disorders) involve problems with the quality, timing, and amount of sleep, which result in daytime distress and impairment in functioning. Sleep-wake disorders often occur along with medical conditions or other mental health conditions, such as depression, anxiety, or cognitive disorders. There are several different types of sleep-wake disorders, of which insomnia is the most common. Other sleep-wake disorders include obstructive sleep apnea, parasomnias, narcolepsy, and restless leg syndrome.

Sleep difficulties are linked to both physical and emotional problems. Sleep problems can both contribute to or exacerbate mental health conditions and can be a symptom of other mental health conditions.

About one-third of adults report insomnia symptoms and 6-10 percent meet the criteria for insomnia disorder.1

Importance of Sleep

Sleep is a basic human need and is critical to both physical and mental health. There are two types of sleep that generally occur in a pattern of three-to-five cycles per night:

• Rapid eye movement (REM) – when most dreaming occurs

• Non-REM – has three phases, including the deepest sleep

When you sleep is also important. Your body typically works on a 24-hour cycle (circadian rhythm) that helps you know when to sleep.

How much sleep we need varies depending on age and varies from person to person. According to the National Sleep Foundation most adults need about seven to nine hours of restful sleep each night. The Foundation revised its sleep recommendations in 2015 based on a rigorous review of the scientific literature.

Many of us do not get enough sleep. Nearly 30 percent of adults get less than six hours of sleep each night and only about 30 percent of high school students get at least eight hours of sleep on an average school night.2 An estimated 35 percent of Americans report their sleep quality as “poor” or “only fair.”3

More than 50 million Americans have chronic sleep disorders.

Insomnia Disorder

Insomnia, the most common sleep disorder, involves problems getting to sleep or staying asleep. About one-third of adults report some insomnia symptoms, 10-15 percent report problems with functioning during the daytime and 6-10 percent have symptoms severe enough to meet criteria for insomnia disorder. An estimated 40-50 percent of individuals with insomnia also have another mental disorder.1

Symptoms and Diagnosis

To be diagnosed with insomnia disorder, the sleep difficulties must occur at least three nights a week for at least three months and cause significant distress or problems at work, school or other important areas of a person's daily functioning. Not all individuals with sleep disturbances are distressed or have problems functioning.

To diagnose insomnia, a physician will rule out other sleep disorders (see Related Conditions below), medication side-effects, substance misuse, depression and other physical and mental illnesses. Some medications and medical conditions can affect sleep.

A comprehensive assessment for insomnia or other sleep problems may involve a patient history, a physical exam, a sleep diary and clinical testing (a sleep study). A sleep study allows the physician to identify how long and how well you’re sleeping and to detect specific sleep problems. A sleep diary is a record of your sleep habits to discuss with your physician. It includes information such as when you go to bed, get to sleep, wake up, get out of bed, take naps, exercise, eat and consume alcohol and caffeinated beverages.

Sleep problems can occur at any age but most commonly start in young adulthood. The type of insomnia often varies with age. Problems getting to sleep are more common among young adults. Problems staying asleep are more common among middle-age and older adults.

Symptoms of insomnia can be:

• Episodic (with an episode of symptoms lasting one to three months)

• Persistent (with symptoms lasting three months or more)

• Recurrent (with two or more episodes within a year)

Symptoms of insomnia can also be brought on by a specific life event or situation.

Disorder

Rapid eye movement (REM) sleep behavior disorder involves episodes of arousal during sleep associated with speaking and/or movement. The person’s actions are often responses to events in the dream, such as being attacked or trying to escape a threatening situation. Speech is often loud, emotion-filled, and profane. These behaviors may be a significant problem for the individual and their bed partner and may result in significant injury (such as falling, jumping, or flying out of bed; running, hitting, or kicking). Upon awakening, the person is immediately alert and can often recall the dream.

These behaviors arise during REM sleep and usually occur more than 90 minutes after falling asleep. The behaviors cause significant distress and problems functioning and may include injury to self or the bed partner. Embarrassment about the episodes can cause problems in social relationships and can lead to social isolation or work-related problems.

The prevalence of REM sleep behavior disorder is less than 1% in the general population and it overwhelmingly affects males older than 50.

narcolepsy have episodes of cataplexy, brief sudden loss of muscle tone triggered by laughter or joking. This can result in head bobbing, jaw dropping, or falls. Individuals are awake and aware during cataplexy.

Narcolepsy nearly always results from the loss of hypothalamic hypocretin (orexin)-producing cells. This deficiency in hypocretin can be tested through cerebrospinal fluid via a lumbar puncture (spinal tap). Narcolepsy is rare, affecting and estimated 0.02%–0.04% of the general population. It typically begins in childhood, adolescence or young adulthood.

Restless Legs Syndrome

Restless legs syndrome involves an urge to move one’s legs, usually accompanied by uncomfortable sensations in the legs, typically described as creeping, crawling, tingling, burning, or itching.

The urge to move the legs:

• begins or worsens during periods of rest or inactivity;

• is partially or totally relieved by movement; and

• is worse in the evening or at night than during the day or occurs only in the evening or at night.

The symptoms occur at least three times per week, continue for at least three months, and cause significant distress or problems in daily functioning. The symptoms of restless legs syndrome can cause difficulty getting to sleep and can frequently awaken the individual from sleep, leading, in turn, to daytime sleepiness.

Restless legs syndrome typically begins in a person’s teens or twenties and it affects an estimated 2% to 7.2% of the population.