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 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, chronic psychophysiologic insomnia, restless legs syndrome, or childhood phobias. Sleep maintenance insomnia suggests major depression, central sleep apnea, obstructive sleep apnea, periodic limb movement disorder, or aging. Falling asleep early and awakening early suggest advanced sleep phase syndrome.
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 or sporting event) 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.
People with insomnia should adhere to a regular awakening time and avoid naps regardless of the amount of nocturnal sleep.
Adequate sleep hygiene can improve sleep.
Adjustment insomnia
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.
Psychophysiologic insomnia
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
Cognitive-behavioral strategies
Hypnotics
Although cognitive-behavioral strategies are more difficult to implement and take longer, effects last a long time after treatment is ended.
These strategies include
Sleep hygiene (particularly restriction of time in bed)
Education
Relaxation training
Stimulus control
Cognitive therapy
Hypnotics 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, cancer, herniated disks), 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. At least 80% of patients with major depression report these symptoms (1). Conversely, 40% of people with chronic insomnia have a major psychiatric 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 Medications and Substances 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.
Reference
1. Geoffroy PA, Hoertel N, Etain B, et al: Insomnia and hypersomnia in major depressive episode: Prevalence, sociodemographic characteristics and psychiatric comorbidity in a population-based study. J Affective Dis 226:132-141.doi.org/10.1016/j.jad.2017.09.032
