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.2
Consequences of Lack of Sleep and Coexisting Conditions
Sleep helps your brain function properly. Not getting enough sleep or poor quality sleep has many potential consequences. The most obvious concerns are fatigue and decreased energy, irritability and problems focusing. The ability to make decisions and your mood can also be affected. Sleep problems often coexist with symptoms of depression or anxiety. Sleep problems can exacerbate depression or anxiety, and depression or anxiety can lead to sleep problems.
Lack of sleep and too much sleep are linked to many chronic health problems, such as heart disease and diabetes. Sleep disturbances can also be a warning sign for medical and neurological problems, such as congestive heart failure, osteoarthritis and Parkinson’s disease.
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.
Treatment and Self-help
Sleep problems can often be improved with regular sleep habits. (See Sleep Hygiene section for tips.) If your sleep problems persist or if they interfere with how you feel or function during the day, you should seek evaluation and treatment by a physician.
Sleep disorders should be specifically addressed regardless of mental or other medical problems that may be present. Chronic insomnia is typically treated with a combination of sleep medications and behavioral techniques, such as cognitive behavior therapy. Several types of medications can be used to treat insomnia and to help you fall asleep or stay asleep. Most of these can become habit-forming and should only be used for short periods and under the care of a doctor. Some antidepressants are also used to treat insomnia.
Most over-the-counter sleep medicines contain antihistamines, which are commonly used to treat allergies. They are not addictive, but they can become less effective over time. They may also contribute to confusion, blurred vision, urinary retention, and falls in the elderly and should be used with caution in this population.
Many people turn to complementary health approaches to help with sleep problems. According to the National Institutes of Health some may be safe and effective, others lack evidence to support their effectiveness or raise safety concerns.
- Relaxation techniques, used before bedtime, can be helpful for insomnia.
- Melatonin supplements may be helpful for people with some types of insomnia. Long-term safety has not been investigated.
- Mind and body approaches, such as mindfulness, meditation, yoga, massage therapy and acupuncture lack evidence to show their usefulness, but are generally considered safe.
- Herbs and dietary supplements have not been shown to be effective for insomnia. There are safety concerns about some, including L-tryptophan and Kava.
Let your health care provider know about any alternative medicines or supplements you are taking.
Sleep Hygiene: Healthy sleep tips to address sleep problems.
- Stick to a sleep schedule – same bed time and wake up time even on the weekends
- Allow your body to wind down with a calming activity, such as reading away from bright lights; avoid electronic devices
- Avoid naps especially in the afternoon
- Exercise daily
- Pay attention to bedroom environment (quiet, cool and dark is best) and your mattress and pillow (should be comfortable and supportive)
- Avoid alcohol, caffeine and heavy meals in the evening
Obstructive sleep apnea involves breathing interruptions during sleep. A person with sleep apnea will have repeated episodes of airway obstruction during sleep causing snoring, snorting/gasping or breathing pauses. This interrupted sleep causes daytime sleepiness and fatigue. Sleep apnea is diagnosed with a clinical sleep study. The sleep study (polysomnography) involves monitoring the number of obstructive apneas (absence of airflow) or hypopneas (reduction in airflow) during sleep.
Sleep apnea affects an estimated 2 to 15 percent of middle-age adults and more than 20 percent of older adults.1 Major risk factors for sleep apnea are obesity, male gender and family history of sleep apnea.
Lifestyle changes, such as losing weight if needed or sleeping on your side, can improve sleep apnea. In some cases a custom-fit plastic mouthpiece can help keep airways open during sleep. The mouthpiece can be made by a dentist or orthodontist. For moderate to severe sleep apnea, a doctor can prescribe a CPAP (continuous positive airway pressure) device. The CPAP works to keep airways open by gently blowing air through a tube and face mask covering your mouth and nose.
Central Sleep Apnea
In central sleep apnea, the brain does not properly control breathing during sleep, causing breathing to start and stop. It is diagnosed when a sleep study identifies five or more central apneas (pauses in breathing) per hour of sleep. Central sleep apnea is rare and less prevalent than obstructive sleep apnea. It is more common in older adults, in people with heart disorders or stroke, and in people using opioid pain medications. It can be treated using a CPAP or other device during sleep.
People with sleep-related hypoventilation have episodes of shallow breathing, elevated blood carbon dioxide levels, and low oxygen levels during sleep. It frequently occurs along with medical conditions, such as chronic obstructive pulmonary disease (COPD), or medication or substance use. Those with sleep-related hypoventilation often have trouble with insomnia or excessive daytime sleepiness. Risk factors for sleep-related hypoventilation include medical conditions, such as obesity and hypothyroidism, and use of certain medications, such as benzodiazepines and opiates.
Other Sleep Disorders
Non-Rapid Eye Movement Sleep Arousal Disorders
Non-rapid eye movement (NREM) sleep arousal disorders involve episodes of incomplete awakening from sleep, usually occurring during the first third of a major sleep episode, and are accompanied by either sleepwalking or sleep terrors. The episodes cause significant distress or problems functioning. NREM sleep arousal disorders are most common among children and become less common with increasing age.
Sleepwalking involves repeated episodes of rising from bed and walking around during sleep. While sleepwalking, the individual has a blank, staring face; is relatively unresponsive to others; and is difficult to wake up. Nearly 30% of people have experienced sleepwalking at some time in their lives. Sleepwalking disorder, with repeated episodes and distress or problems functioning, affects an estimated 1% to 5% of people.
Sleep terrors (also called night terrors) are episodes of waking abruptly from sleep, usually beginning with a panicky scream. During each episode, the person experiences intense fear and associated physical signs such as rapid breathing, accelerated heart rate and sweating. The person typically does not remember much of the dream and is unresponsive to efforts of others to comfort them. Sleep terrors are common among very young children—at 18 months of age about 37% of children experience night terrors and at 30 months about 20% experience them. Only about 2% of adults experience night terrors.
Nightmare disorder involves repeated occurrences of lengthy, distressing, and well-remembered dreams that usually involve efforts to avoid threats or danger. They generally occur in the second half of a major sleep episode.
The nightmares are typically lengthy, elaborate, story-like sequences of dream imagery that seem real and cause anxiety, fear or distress. After waking up, people experiencing nightmares are quickly alert and generally remember the dream and can describe it in detail. The nightmares cause significant distress or problems functioning. Nightmares often begin between ages 3 and 6 years but are most prevalent and severe in late adolescence or early adulthood.
Rapid Eye Movement Sleep Behavior 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.
People with hypersomnolence disorder are excessively sleepy even when getting at least 7 hours sleep. They have at least one of the following symptoms:
- Recurrent periods of sleep or lapses into sleep within the same day (such as unintentional naps while attending a lecture or watching TV)
- Sleeping more than nine hours per day and not feeling rested
- Difficulty being fully awake after abruptly waking up
The extreme sleepiness occurs at least three times per week, for at least three months. Individuals with this disorder may have difficulty waking up in the morning, sometimes appearing groggy, confused or combative (often referred to as sleep inertia). The sleepiness causes significant distress and can lead to problems with functioning, such as issues with concentration and memory.
The condition typically begins in late teens or early twenties but may not diagnosed until many years later. Among individuals who consult in sleep disorders clinics for complaints of daytime sleepiness, approximately 5%–10% are diagnosed with hypersomnolence disorder.
People with narcolepsy experience periods of an irrepressible need to sleep or lapsing into sleep multiple times within the same day.
Sleepiness typically occurs daily but must occur at least three times a week for at least three months for a diagnosis of narcolepsy. People with 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.
Circadian Rhythm Sleep-Wake Disorders
With circadian rhythm sleep-wake disorders, a person’s sleep-wake rhythms (body clock) and the external light-darkness cycle become misaligned. This misalignment causes significant ongoing sleep problems and extreme sleepiness during the day leading to significant distress or problems with functioning.
Circadian rhythm disorders can be caused by internal factors (a person’s body clock is different than the light-dark cycle) or external factors (such as shift work or jet lag).
Prevalence of delayed sleep phase type (staying up late and getting up late) in the general population is approximately 0.17% but estimated to be greater than 7% in adolescents. The estimated prevalence of advanced sleep phase type (going to sleep early and waking early) is approximately 1% in middle-age adults and it is more common in older adults.
- American Psychiatric Association.Diagnostic and Statistical Manual of Mental Disorders (DSM-5), Fifth edition. 2013.
- Centers for Disease Control and Prevention. Insufficient Sleep is a Public Health Problem. Accessed July 2017.
- National Sleep Foundation. Sleep Health Index. 2014.
Felix Torres, MD, MBA, DFAPA