Many sleep disorders manifest with insomnia and usually excessive daytime sleepiness (EDS).
Insomnia is difficulty falling or staying asleep, early awakening, or a sensation of unrefreshing sleep.
EDS is the tendency to fall asleep during normal waking hours.
(See also Approach to the Patient With a Sleep or Wakefulness Disorder Approach to the Patient With a Sleep or Wakefulness Disorder Almost half of all people in the US report sleep-related problems. Disordered sleep can cause emotional disturbance, memory difficulty, poor motor skills, decreased work efficiency, and increased... read more for general information about sleep disorders and about their evaluation and treatment.)
Insomnia can be a disorder, even if it exists in the context of other disorders, or can be a symptom of other disorders. EDS is not a disorder but a symptom of various sleep-related disorders.
Difficulty falling asleep (sleep-onset insomnia) should be distinguished from difficulty maintaining sleep and early awakening (sleep maintenance insomnia) because the causes differ. Sleep-onset insomnia suggests delayed sleep phase syndrome Circadian rhythm sleep disorder, altered sleep phase types Circadian rhythm sleep disorders are caused by desynchronization between internal sleep-wake rhythms and the light-darkness cycle. Patients typically have insomnia, excessive daytime sleepiness... read more , chronic psychophysiologic insomnia, restless legs syndrome Periodic Limb Movement Disorder (PLMD) and Restless Legs Syndrome (RLS) Periodic limb movement disorder (PLMD) and restless legs syndrome (RLS) are characterized by abnormal motions of and, for RLS, usually sensations in the lower or upper extremities, which may... read more , or childhood phobias. Sleep maintenance insomnia suggests major depression Major depression (unipolar disorder) Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more , central sleep apnea Central Sleep Apnea Central sleep apnea (CSA) is a heterogeneous group of conditions characterized by changes in ventilatory drive without airway obstruction. Most of these conditions cause asymptomatic changes... read more , obstructive sleep apnea Obstructive Sleep Apnea Obstructive sleep apnea (OSA) consists of episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of apnea or... read more , periodic limb movement disorder Periodic Limb Movement Disorder (PLMD) and Restless Legs Syndrome (RLS) Periodic limb movement disorder (PLMD) and restless legs syndrome (RLS) are characterized by abnormal motions of and, for RLS, usually sensations in the lower or upper extremities, which may... read more , or aging. Falling asleep early and awakening early suggest advanced sleep phase syndrome Circadian rhythm sleep disorder, altered sleep phase types Circadian rhythm sleep disorders are caused by desynchronization between internal sleep-wake rhythms and the light-darkness cycle. Patients typically have insomnia, excessive daytime sleepiness... read more .
Sleep disorders may be caused by factors inside the body (intrinsic) or outside the body (extrinsic).
Inadequate sleep hygiene
Sleep is impaired by certain behaviors. They include
Consumption of caffeine or sympathomimetic or other stimulant drugs (typically near bedtime, but even in the afternoon for people who are particularly sensitive)
Exercise or excitement (eg, a thrilling television show) late in the evening
An irregular sleep-wake schedule
Patients who compensate for lost sleep by sleeping late or by napping may further fragment nocturnal sleep.
Insomniacs should adhere to a regular awakening time and avoid naps regardless of the amount of nocturnal sleep.
Acute emotional stressors (eg, job loss, hospitalization, a death in the family) can cause insomnia. Symptoms typically remit shortly after the stressors abate; insomnia is usually transient and brief. Nevertheless, if daytime sleepiness and fatigue develop, especially if they interfere with daytime functioning, short-term treatment with hypnotics at bedtime is warranted. Persistent anxiety may require specific treatment.
Insomnia, regardless of cause, may persist well beyond resolution of precipitating factors, usually because patients feel anticipatory anxiety about the prospect of another sleepless night followed by another day of fatigue. Typically, patients spend hours in bed focusing on and brooding about their sleeplessness, and they have greater difficulty falling asleep in their own bedroom than falling asleep away from home.
Optimal treatment combines
Although cognitive-behavioral strategies are more difficult to implement and take longer, effects last a long time after treatment is ended.
These strategies include
Hypnotics Hypnotics Almost half of all people in the US report sleep-related problems. Disordered sleep can cause emotional disturbance, memory difficulty, poor motor skills, decreased work efficiency, and increased... read more are suitable for patients who need rapid relief and whose insomnia has had daytime effects, such as EDS and fatigue. These drugs must not be used indefinitely in most cases.
Insomnia related to physical disorders
Physical disorders may interfere with sleep and cause insomnia and EDS. Disorders that cause pain or discomfort (eg, arthritis Osteoarthritis (OA) Osteoarthritis is a chronic arthropathy characterized by disruption and potential loss of joint cartilage along with other joint changes, including bone hypertrophy (osteophyte formation). Symptoms... read more , cancer Overview of Cancer Cancer is an unregulated proliferation of cells. Its prominent properties are A lack of differentiation of cells Local invasion of adjoining tissue Metastasis, which is spread to distant sites... read more , herniated disks Herniated Nucleus Pulposus Herniated nucleus pulposus is prolapse of an intervertebral disk through a tear in the surrounding annulus fibrosus. The tear causes pain due to irritation of sensory nerves in the disk, and... read more ), particularly those that worsen with movement, cause transient awakenings and poor sleep quality. Nocturnal seizures can also interfere with sleep.
Treatment is directed at the underlying disorder and symptom relief (eg, with bedtime analgesics).
Insomnia related to mental disorders
Most major mental disorders can cause insomnia and EDS. About 80% of patients with major depression Major depression (unipolar disorder) Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more report these symptoms. Conversely, 40% of chronic insomniacs have a major mental disorder, most commonly a mood disorder.
Patients with depression may have initial sleeplessness or sleep maintenance insomnia. Sometimes in the depressed phase of bipolar disorder and in seasonal affective disorder, sleep is uninterrupted, but patients complain of unrelenting daytime fatigue.
If depression is accompanied by sleeplessness, antidepressants that provide more sedation (eg, citalopram, paroxetine, mirtazapine) may help patients sleep. These drugs are used at regular, not low, doses to ensure correction of the depression. However, clinicians should note that these drugs are not predictably sedating and may have activating properties. In addition, the sedation provided may outlast its usefulness, causing EDS, and these drugs may have other adverse effects, such as weight gain. Alternatively, any antidepressant may be used with a hypnotic.
If depression is accompanied by EDS, antidepressants with activating qualities (eg, bupropion, venlafaxine, certain selective serotonin reuptake inhibitors [SSRIs] such as fluoxetine and sertraline) may be chosen.
Insufficient sleep syndrome (sleep deprivation)
Patients with insufficient sleep syndrome do not sleep enough at night to stay alert when awake. The cause is usually various social or employment commitments. Insufficient sleep syndrome is probably the most common cause of EDS, which disappears when sleep time is increased (eg, on weekends or vacations). After long periods of sleep deprivation, weeks or months of extended sleep are needed to restore daytime alertness.
Drug-related sleep disorders
Insomnia and EDS can result from chronic use of central nervous system (CNS) stimulants (eg, amphetamines, caffeine), hypnotics (eg, benzodiazepines), other sedatives, antimetabolite chemotherapy, antiseizure drugs (eg, phenytoin), methyldopa, propranolol, alcohol, and thyroid hormone preparations (see table Some Drugs That Interfere With Sleep Some Drugs That Interfere With Sleep ). Commonly prescribed hypnotics can cause irritability and apathy and reduce mental alertness. Many psychoactive drugs can induce abnormal movements during sleep.
Insomnia can develop during withdrawal of CNS depressants (eg, barbiturates, opioids, sedatives), tricyclic antidepressants, monoamine oxidase inhibitors, or illicit drugs (eg, cocaine, heroin, marijuana, phencyclidine). Abrupt withdrawal of hypnotics or sedatives can cause nervousness, tremors, and seizures.