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 4-22% 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, preferably with consistent sleep and wake times.
Many of us do not get enough sleep. A third of adults report that they usuallget less than the recommended amout of sleep and only about 30% of high school students get at least eight hours of sleep on an average school night.2 An estimated 34 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, diabetes and obesity. Sleep disturbances can also be a warning sign for medical and neurological problems, such as congestive heart failure, osteoarthritis and Parkinson’s disease.
Types of Sleep Disorders - Insomnia and Sleep Apnea
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 to 15% report problems with functioning during the daytime and 4 to 22% have symptoms severe enough to meet criteria for insomnia disorder. An estimated 40 to 50% 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 with 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 or polysomnography). 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. In additional, a sleep study allows the physician to identify howlong and how well you are sleeping and to detect specific sleep problems.
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-aged 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 physician. 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, while others may interact with prescribed medications.
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 bedtime 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 and avoiding electronic devices before sleep.
- 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.
Sleep Apnea
Obstructive sleep apnea hypopnea, most commonly called 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 is a very common disorder with the prevalence particularly high among men as campared to women, inoder adults, and certain racial and ethnic groups (including African Americans, American Indians, and Hidpanics). Major risk factors for sleep apnea are obesity, male gender, family history of sleep apnea, menopause and certain genetic or endocrine disorders.
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 physician can prescribe a CPAP (continuous positive airway pressure) device. The CPAP works to keep your airways open by gently blowing air through a tube and face mask covering your mouth and/or nose.
Other Sleep Disorders
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, frequently waking up during sleep and headaches on awakening. Risk factors for sleep-related hypoventilation include medical conditions, such as obesity, hypothyroidism, pulminary disorders; neuromuscular disorders; the use of certain medications, such as benzodiazepines and opiates; and alcohol.
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 with 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 stare; is relatively unresponsive to others; is difficult to awaken, and will have limited recall for the episode once awake. Between 6.9 and 29.2% of people have experienced sleepwalking at some time in their lives.
Sleep terrors (also called night terrors) are episodes of waking abruptly from sleep, usually beginning with a panicky scream or cry. 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 with 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 (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 arise during REM sleep and usually occur omore than 90 munites after falling asleep. Upon awakening, the person is immediately alert and can often recall the dream.
REM sleep behavior disorders may cause significant distress and problems with functioning, including injury to the individual and their bed partner (such as falling, jumping, or flying out of bed; running, hitting, or kicking). 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 has been estimated at around 1% in the general population and may be greater in individuals with psychiatric disorers, possibl related to prescribed medications.
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 adulthood but may not be diagnosed until many years later. Among individuals who consult in sleep disorders clinics for complaints of daytime sleepiness, approximately 5 to 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-producing cells. This deficiency in hypocretin (also known as orexin) can be tested in the cerebrospinal fluid via a lumbar puncture (spinal tap). Narcolepsy is rare, affecting and estimated 0.02 to 0.05% of the adult general population. It typically begins in childhood, adolescence or young adulthood.
Restless legs syndrome (RLS) involves an urge to move one’s legs, usually accompanied by uncomfortable and unpleasant 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
- Occurs only in the evening or at night (or is worse in the evening or at night than during the day).
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 RLS can cause difficulty getting to sleep and can frequently awaken the individual from sleep, leading, in turn, to daytime sleepiness.
RLS typically begins in a person’s teens or twenties, and it affects up to 3% of the poopulation.
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 adult population has been estaimated betweeen 0.2 and 1.7% but may be as high as 4.6% in adolescents. The estimated prevalence of advanced sleep phase type (going to sleep early and waking early) is approximately 1% in middle-aged adults and it is more common in older adults.
References
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR), Fifth edition - Text Rivision. 2022.
- Centers for Disease Control and Prevention. Sleep and Sleep Disorders.
- National Sleep Foundation. Sleep Health Index. 2017.
Physician Review
Felix Torres, M.D., MBA, FACHE, DFAPA, CCHP-MH
March 2024