Insomnia

Editor's Note: This issue of In the Clinic has been updated. People with insomnia have trouble falling or staying asleep, and the result is poor-quality sleep of insufficient duration. Insomnia is common, affecting 1 in 3 adults intermittently and 1 in 10 adults chronically, and can seriously affect wellbeing. It typically causes excessive daytime sleepiness, irritability, and lack of energy. Long-term insomnia may lead to depression, inattention, learning and memory problems, and job or school underperformance. Given these substantial health consequences and the prevalence of insomnia, clinicians should be skilled in managing it. Clinical Slide Set. Insomnia Screening Which patient populations have the highest prevalence of insomnia? People especially prone to insomnia include those who are under stress, are depressed or have other emotional distress, are working at night or having frequent major shifts in their work hours, or are traveling long distances with time changes (1). Insomnia can occur at any age, but it is particularly prevalent in the elderly. One large study found that the prevalence of insomnia complaints ranged between 23% and 34% among people 65 years and older (2). Among this population, sleep complaints are commonly associated with medication use and medical problems (3). Population-based studies have found an association between lower socioeconomic status and insomnia (4, 5). Should clinicians screen for insomnia? If so, how should they screen? Clinicians should consider screening for insomnia as part of regular patient care given its high prevalence and potential impact on wellbeing. Insomnia puts people at increased risk for poor health, and it can also reduce work performance and quality of life (6, 9). Evidence that screening for insomnia improves patient outcomes is not available. However, screening can be accomplished in a relatively straightforward, brief manner by asking patients about trouble initiating or maintaining sleep, early morning waking, or nonrestorative sleep (10). Further evaluation can be limited to individuals with these complaints. Clinical Bottom Line: Screening Given the high prevelance of insomnia and its potential impact on health and quality of life, clinicians should consider incorporating screening for insomnia as a regular part of patient care. It can be done in a relatively straightforward way that does not take long by asking patients about difficulty initiating or maintaining sleep, early morning awakening, or nonrestorative sleep. People prone to insomnia are those who are under a lot of stress; who are depressed or have other emotional distress; and those who work nights, have frequent major shifts in their work hours, or travel long distances with time changes. Diagnosis What are the components of a comprehensive sleep history? A consensus paper from the American Academy of Sleep Medicine recommends detailed historical information, as well as medical, psychological, and psychiatric assessment to evaluate insomnia (11). Comprehensive assessment enables clinicians to establish the cause of insomnia and to plan effective treatment. Things to Ask about When Taking a Comprehensive Sleep History Problems of sleep initiation, sleep maintenance, early morning waking, or nonrestorative sleep Ascertain if the patient has acute, short-term, or chronic insomnia Stability or progression of symptoms—that is, if the insomnia is stable, worsening, or improving Precipitating causes of insomnia Bedtime, wake time, length of sleep time Caffeine and alcohol use Any current or previous behavioral therapies used to treat insomnia Previous over-the-counter or prescription sedative-hypnotic use Shifting work and irregular sleep schedule Potential acute stressors, such as: Medical or psychiatric illness Medication use, both prescribed and illicit Acute stress at home or work ircadian rhythm stressors, such as jet lag Clinicians should ask about specific sleep complaints and duration, sleep hygiene, mood disorders, underlying medical disorders, medication use, and substance use. Patient sleep diaries can supplement history by helping to obtain a more accurate record of sleep habits than general questioning alone and to assess total sleep time. If asking patients to keep a sleep diary, clinicians should instruct them to record bedtime, sleep time, nocturnal waking, and rising time in sleep diaries daily for at least 1 to 2 weeks. Standardized sleep questionnaires are primarily used in research settings, but their utility in clinical settings is uncertain. Which conditions should clinicians consider as potential secondary causes of insomnia? The most common type of insomnia is secondary insomnia, meaning that it is attributable to an underlying condition, poor sleep environment, or use of medications or other substances that interfere with sleep. A longitudinal study of more than 200 general medical patients found a strong linkage between severe insomnia and chronic medical and psychiatric disorders (12). A study of 2398 community-dwelling individuals aged 65 years and older found that sleep complaints were common and associated with a range of medications and medical problems (3). The American Sleep Disorders Association released an international classification of sleep disorders manual to better define these various causes (13). Tables 1 and 2 summarize the main considerations in the differential diagnosis of potential causes of secondary insomnia. Table 1. Differential Diagnosis of Underlying Causes of Insomnia Table 2. Other Medical Disorders that Can Be Underlying Causes of Insomnia What is the role of physical examination in the evaluation of patients with insomnia? The physical examination can identify signs that suggest a specific disorder underlying insomnia. Underlying causes include obstructive sleep apnea syndrome (OSAS), obesity, hypertension, thyroid dysfunction, restless leg syndrome (RLS), or other cardiopulmonary or neurologic disease When should clinicians consider laboratory testing in the evaluation of patients with insomnia? Laboratory testing should not be used routinely in the evaluation of insomnia. However, judicious use may be indicated in some patients with clinical evidence of concomitant disease that may be associated with insomnia (10). Polysomnography The American Academy of Sleep Medicine report recommends using polysomnography (overnight sleep test) or a multiple sleep latency test (MSLT), or both, to evaluate patients with sleep-disordered breathing; specific sleep disorders, such as narcolepsy and periodic limb movements; or insomnia resistant to initial therapeutic measures (14). Multiple Sleep Latency Test (MLST) The MSLT is a standard nap test that takes place in a sleep laboratory after an overnight sleep study. This test is a series of four 20-minute naps designed to objectively measure daytime sleepiness and the onset of REM sleep. A latency of less than 8 minutes to stage 1 sleep suggests pathologic hypersomnolence. Sleep Actigraphy In this noninvasive test, the patient wears a small, watch-like electronic device around the wrist of the nondominant arm for an extended period of time. Although actigraphy provides an accurate recording of sleep patterns, it may underestimate severity in patients with sleep-onset insomnia. Sleep actigraphs can provide a reliable measurement of sleep patterns and circadian rhythms (15) and are most often used in research settings. Other Tests to Evaluate for Underlying Comorbidity Various other tests may be needed to check for underlying cardiac, pulmonary, gastrointestinal, or neurologic disorders contributing to or causing the insomnia. Complete blood count and serum ferritin levels can identify anemia, which is associated with RLS. A blood urea nitrogen test and serum creatinine test can check for renal disease, which is also associated with RLS. Thyroid function tests can reveal hypothyroidism or hyperthyroidism, conditions that are associated with sleep problems. Urine drug screening may also be useful, because stimulant medication and benzodiazepine hypnotic medications may alter sleep. Clinicians should consider electrocardiography and echocardiography if there is a concern about congestive heart failure, which can interfere with sleep. A chest X-ray may be used to identify heart failure or chronic obstructive pulmonary disease. In patients with respiratory symptoms, pulmonary function testing may identify upper and lower airway obstruction. Barium swallow and 24-hour pH probe may be helpful in the evaluation of patients in whom symptoms suggest that gastroesophageal reflux may be contributing to insomnia. Clinical Bottom Line: Diagnosis Insomnia is most often due to underlying medical or psychological conditions, medications or other substances that interfere with sleep, or poor sleep environment. A detailed history and physical evaluation is necessary in the evaluation of insomnia. This might include the use of sleep diaries, sleep questionnaires, and laboratory testing to evaluate for underlying conditions. Treatment What is sleep hygiene and what is its role in the treatment of patients with insomnia? Sleep hygiene is the practice of following simple guidelines (see Box) to promote sound sleep and daytime alertness. Good sleep hygiene behaviors: Maintain stable bed times and rising times Spend no more than 8 hours in bed Experience regular daytime light exposure Maintain a quiet, dark bedroom Maintain adequate nutrition Avoid sleep-fragmenting substances, such as caffeine, nicotine, and alcohol Avoid clock-watching Maintain regular exercise Avoid heavy exercise within 2 hours of bedtime Avoid bright light before bedtime Maintain a 30-minute relaxation period before bedtime Avoid using alcohol to initiate sleep Poor sleep hygiene can contribute to sleep fragmentation, circadian rhythm disturbance, discomfort, and overstimulation. Clinicians should review and correct poor sleep hygiene in all patien