Insomnia: A Practical Review

Insomnia: A Practical Review ELSEVIER

General Medicine Update

Lori A. Bastian, MD, MPH, M. Christine Crenshaw, PhD, and David C. Steffens, MD DEPARTMENTS OF M E D I C I N E AND PSYCHIATRY AND BEHAVIORAL SCIENCES, D U K E U N I V E R S I T Y M E D I C A L C E N T E R ; WOMEN VETERANS COMPREHENSIVE HEALTH CENTER; AND CENTER FOR HEALTH SERVICES RESEARCH IN PRIMARY CARE, VETERANS AFFAIRS MEDICAL CENTER, DURHAM, NORTH CAROLINA, U.S.A.

Abstract

Introduction

Insomnia has two components: the subjective complaint of trouble sleeping and a perceived daytime consequence of the nocturnal problem. The prevalence of insomnia in the general population is high, and the problem

Although psychiatrists, like other physicians, often treat the symptom of insomnia associated with mental illness, they need to be familiar with medical causes of insomnia as well as advances in the diagnosis and treatment of sleep disorders. This review will address the common causes of insomnia and will briefly discuss common primary sleep disorders. We present some targeted questions for use during a clinical interview. We also present a diagnostic strategy for the evaluation of insomnia and sleep disorders with appropriate treatment and referral. Insomnia can be a symptom of many medical and psychological disorders. It warrants assessment and treatment when the patient presents with both 1 ) a subjective complaint of trouble sleeping and 2) a perceived daytime consequence of the noeturnal problem. This clinical definition of insomnia therefore would not include the person who only sleeps 4 hours but feels fine the next day. Appropriate assessment of the patient with an insomnia complaint is essential because treatment of specific etiologic factors which may underlie the insomnia (e.g., sleep apnea, pain, depression) is usually better in the long term than treatment of the insomnia symptoms only ( 1 ). It should also be noted that the subjective complaint of trouble sleeping does not always correlate with objective evidence of sleep disruption.

increases with increasing age. Psychiatrists usually encounter insomnia

complaints that result from either comorbid mental illness or a side effect of pharmacotherapy. Clinicians should be aware of the multiple nonpsychiatric causes of insomnia and be familiar with common primary sleep disorders. Obtaining a medical and sleep history is a critical first step in securing a diagnosis. Polysomnographic measurements, although not

always necessary, provide definitive information that will assist in diagnosing sleep disorders. When the diagnosis requires monitoring the patient in a sleep laboratory, the clinician may choose to consult a sleep specialist. In general, drug therapy is recommended only as an adjunctive measure and on a short-term basis. Treatmerit should be directed at the underlying condition, management of stress, and improvement of sleep hygiene. This review, with case examples, highlights some common etiologies of insomnia, outlines both pharmacologic and nonpharmacologic treatment options, and discusses when to refer potential sleep disorder cases to a specialist. Published by Elsevier Science Inc., 1996.

MEDICAL UPDATE FOR PSYCHIATRISTS 1;6:183-187, 1996

Epidemiologg Approximately one third of the adult population may complain of insomnia in a given year, and half of these individuals will subjectively rate their problems as severe. About 5% of the general adult population has a prescription for psychotropic medication for sleep and at

Published bu Elsevier Science Inc., 199G ISSN !082-757919G150.00 PII S1082-7§79(9GIOQ080-5

Address reprint requests to: Dr. Lori Bastian, Durham VAMC, 508 Fulton Street (152), Durham, NC 27705.

least another 3% uses over-the-counter preparations (2). Insomnia affects persons of both sexes and of all ages, races, and socioeconomic groups (3). There are several sociodemographic and clinical risk factors for insomnia that can help target patient populations who are more important to screen. Women are at greater risk than men. In both sexes older age is a risk factor. Taking multiple medications and having a history of alcohol abuse, substance abuse, or chronic illness are also risk factors for insomnia. Persons who are of lower socioeconomic status are at risk for insomnia as are persons who are divorced, widowed, or separated (2).

Normal Sleep PhusiologiJ To feel adequately restored after sleep, both one's duration and stages of sleep should follow a normal pattern. This pattern, referred to as normal physiologic sleep architecture, is characterized by two basic sleep phases: rapid eye movement (REM) and non-REM. The characteristics of REM sleep include rapid eye movements, loss of muscle tone, and an electroencephalographic (EEG) profile that is most similar to waking EEG patterns. Four levels of non-REM sleep have been distinguished based on variations in the sleep pattern. These four non-REM stages are considered to present a continuum of depth of sleep, with Stage 1 being the lightest and Stage 4 the deepest. Stages 3 and 4 are often considered together, and are referred to as delta sleep, or slow wave sleep. Normal sleep in healthy adults usually begins with a short period of light sleep followed by a longer period of delta sleep. This is then followed by a period of REM sleep. This cycle of non-REM and REM sleep then repeats, usually four to five times over the course of the night, with relatively more REM sleep and less slow wave sleep occurring during each successive cycle as the sleeper progresses through the night. Typically, the first

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REM period occurs 90 minutes after sleep onset (4,5).

order due to a general medical condition, and 4) substance-induced sleep disorder (Table 1 ).

Cfinical Evaluation

Case 1

When a patient presents with symptoms suggestive of insomnia, the physician must construct and consider a differential diagnosis. There are several different classification systems for sleep disorders, including the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), the Diagnostic Classification of Sleep and Arousal Disorders, and the International Classification of Sleep Disorders. It has been argued that a broader classification scheme such as that used in DSM-IV may be better suited to the practicing physician, whereas the more extensive and narrowly focused system(s ) may be preferable for the specialist (6). The DSM-IV classifies sleep disorders broadly into four categories, according to presumed etiology: 1 ) primary sleep disorders, 2) sleep disorder related to another mental disorder, 3) sleep dis-

Mrs. A is a 40-year-old mother of three children who developed trouble sleeping when her husband took a 2-week business trip to Japan. After 3 sleepless nights and extreme daytime exhaustion, she calls her primary care physician asking for something to help her sleep. The physician is reluctant to prescribe her a hypnotic because "sleeping pills are addicting." By the time her husband returns home from his trip, Mrs. A is anxious, irritable, and completely ineffective at work. Diagnosis. Temporary insomnia, which

does not meet DSM-W criteria for primary insomnia (code 307.42) because symptoms last > 1 month. An insomnia complaint may also be broadly characterized according to its duration. Transient and short-term in-

Talllo i. DSM IV Classification of Sleep Disorders (4) I. Primary sleep disorders Dyssomnias Primary insomnia 307.42 Primary hypersomnia 307.44 Narcolepsy 347 Breathing-related sleep disorder 780.59 Circadian rhythm sleep disorder 307.45 Dyssomnia not otherwise specified 307.47 Parasomnias Nightmare disorder 307.47 Sleepwalking disorder 307.46 Sleep terror disorder 307.46 Parasomnia not otherwise specified II. Insomnia related to another mental disorder 307.42 Mood disorders (major depression and bipolar disorder) Anxiety disorders (general anxiety disorder, panic disorder, and PTSD) Psychotic disorders (i.e., acute exacerbation of schizophrenia) Somatoform disorders Personality disorders III. Sleep disorder due to a general medical condition 780.xx Insomnia type 780.52 Hypersomnia type 780.54 Parasomnia type 780.59 Mixed type 780.59 IV. Substance-induced sleep disorder (substances, including medications) Alcohol 291.8 Amphetamine 292.89 Caffeine 292.89 Cocaine 292.89 Opioid 292.89 Sediative, hypnotic, or anxiolytic 292.89 Other 292.89

somnia is classified as temporary, whereas chronic ( > 4 weeks) is classified as persistent. Temporary insomnia is characterized by hyperarousal and often can be attributed to an acute disturbance of the normal circadian rhythm such as jet lag, or to a change in the work schedule, the death of a loved one, or the birth of a child. An environmental disturbance such as sleeping in an unfamiliar bed or a change in altitude may cause temporary insomnia as well. Mthough by definition this is not a longterm problem, it is important because it may result in a decrement of daytime functioning or alertness: 15-20% of all freeway accidents result from falling asleep at the wheel (7). Case 2

Ms. M is 47 years old with no significant medical problems. She is referred to a psychiatrist to rule out depression. She has been complaining of early morning awakening and irritability, which she attributes to fatigne. She denies a depressed mood and claims no new stresses in her life. A detailed sleep history taken by the psychiatrist reveals that she is awakened by night sweats and has had "hot flashes" during the day. The psychiatrist refers Ms. M to a gynecologist to rule out symptoms of menopause and the need for estrogen replacement therapy. Diagnosis. Menopausal symptoms, no

sleep disorder diagnosis. Most cases of chronic insomnia are due to underlying medical or psychiatric conditions (6). Medical illnesses that can cause insomnia include most chronic conditions, but in particular rheumatoid arthritis, peptic ulcer disease, asthma, chronic pain, angina and coronary artery disease, congestive heart failure, hyperthyroidism, symptoms of menopause, nocturnal leg cramps, and nocturia (most commonly associated with benign prostatic hypertrophy). The psychiatric consultant must be aware of these common medical conditions and their role in causing insomnia so that the patient receives appropriate treatments (Table 2). Case 3

Mr. R is 60 years old with severe degenerative joint disease of his hips and knees. He has a history of occasional joint pain at night. Six weeks ago, he

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Table 2. Nonpsychiatrie Conditions that

Can Cause Insomnia

min. A thorough medical workup including cardiac consultation is negative.

Asthma

Diagnosis.

Chronic obstructive pulmonary disease Coronary artery disease and angina Congestive heart failure

Nocturnal panic, DSM-IV

code 300.1.

Seizure disorders Migraine headaches

Anxiety disorders which include panic disorder and post-traumatic stress disorder (PTSD) are associated with 40% of persistent insomnia, whereas depression is found in 20% of all persistent insomnia cases. Less common is mania and hypomania, which may result in an agitated insomnia. Both alcohol use and abuse result in 12% of persistent insomnia, and patients often treat insomnia with more alcohol.

Parkinson's disease Dementia

Case 5

Hypoglycemia Hyperthyroidism Menopause/pregnancy Fibromyalgia Rheumatoid arthritis Chronic pain syndromes

Chronic liver failure Peptic ulcer disease Gastroespohageal reflux disease Benign prostatic hypertrophy with nocturia Chronic renal failure Nocturnal leg cramps Restless leg syndrome

was prescribed prednisone for his pain, which he states has helped. He now complains of more trouble sleeping, and his wife calls because she is concerned. Diagnosis. Substance-induced sleep disorder, insomnia type, DSM-IV code 292.89.

Multiple drugs and substances can cause insomnia. Over-the-counter medications such as cold remedies, diet pills, caffeine, and nicotine are significant culprits. Prescription drugs such as selective serotonin reuptake inhibitors (SSRIs), steroids, diuretics, theophylline,/3-agonists, propranolol, and lovastatin have been identified to cause insomnia. In addition, withdrawal of benzodiazepines, tricyclic antidepressants, and barbiturates can result in agitation and insomnia.

Case 4

Ms. B is a 23-year-old without significant medical or psychiatric history, whose sleep becomes disrupted several times a week by sudden onset of tachycardia, tachypnea, nausea, sweating, tremulousness, and fear lasting about 20

Mr. J is a 48-year-old Vietnam war veteran with a history of disturbing nightmares and flashbacks. He was diagnosed and treated for PTSD with significant improvement in his symptoms. He presents to his psychiatrist complaining of daytime somnolence. The psychiatrist talks to the patient's wife and discovers that his snoring is keeping her a w a k e and he has had trouble recently maintaining an erection.

Diagnosis.

Breathing-relating sleep disorder, DSM-IV code 780.59.

Breathing-related sleep disorders such as sleep apnea have a prevalence of 110% in adults. Additional primary sleep disorders include periodic limb movement disorder (nocturnal myoclonus) and restless leg syndrome, lmss common are delayed sleep phase syndrome and narcolepsy. Specific patient characteristics that would increase a physician's suspicion of sleep apnea include: obesity or weight gain, morning headaches, irritability, impotence, and loud snoring. Excessive daytime somnolence is usually a prominent feature; assessment of that includes asking whether the patient has fallen asleep at the wheel and whether the patient needs to nap during the day. It is often useful to ascertain if a bed partner has ever observed irregular breathing or apneic events.

Treatment

When reviewing treatment options for either temporary or persistent insomnia, the clinician must first consider whether 185

a nonpharmacologic intervention may suffice. Sleep hygiene principles (Table 3) are useful to reinforce regardless of the cause and duration of the insomnia. Patients should be instructed on the following basic sleep principles: keep a regular sleep schedule and do not exercise immediately before bedtime; reserve your bed for sleep; attempt to relax prior to going to bed (e.g., read a book or take a bath); keep your bedroom dark; avoid naps during the day; do not use cigarettes or alcohol within 3 - 4 hours of bedtime; and do not drink caffeinated beverages within 6 hours of bedtime. Keeping a sleep diary helps to identify problem habits. Nonmedieal therapies for insomnia often require a psychology referral. These therapies include stimulus control, sleep restriction, relaxation training, hypnosis, and cognitive behavior therapy. All of these techniques share some basic principles of classical conditioning. Stimulus control involves conditioning the patient's sleep response to occur in and only in the presence of the appropriate stimulus (bed). If the patient with insomnia is unable to sleep while in bed, he is instructed to get out of bed and go into another room until he feels sleepy. In time, this will break the link or association between insomniac behaviors (tossing and turning, worrying in bed) and the stimulus. Conversely, the patient is forbidden to sleep in any context other than bed, to strengthen the association between the stimulus (bed) and the desired response (sleep).

Table 3. Sleep Hygiene Counseling (15)

1. Go to bed only when sleepy. 2. Use the bed only for sleeping; do not read. 3. If unable to sleep, get up and move to another room. Stay up until you are definitely sleepy and then return to bed. If sleep still does not come easily, get out of bed again. The goal is to associate your bed with falling asleep quickly. 4. Repeat Step 3 as often as is necessary throughout the night. 5. Set the alarm and get up at the same time every morning, regardless of how much you have slept during the night. Do not nap during the daytime. This guideline helps the body acquire a constant sleep-wake rhythm.

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Sleep restriction is similar to stimulus control in that the patient's time in bed is restricted to increase the hkelihood that sleep--and not ineffective tossing and turning--will take place in bed. As sleep efficiency (the ratio of time asleep to time spent in bed) improves, the restrictions on time in bed are eased, until optimal sleep time is achieved. Relaxation training, cognitive therapy, and hypnosis or meditation are therapies aimed at promoting the patient's physical and psychological readiness for sleep. The patient is trained in the self-use of techniques such as progressive muscle relaxation and deep breathing, together with imagery, hypnotic suggestion, or cognitive restructuring, to minimize negative cognitions while in bed, promote physiologic relaxation, and enhance the patient's sense of control over sleep initiation. Research has found these therapies, alone or in combination, to be effective in such subgroups as patients who have sleep disturbance resulting from chronic pain (8), and geriatric patients with sleep maintenance insomnia (9). Bright light therapy is a somatic treatment that has been shown to be effective in treatment of insomnia and circadian rhythm disorders when the patient's sleep-wake schedule is not in synehrony with her social or occupational demands. Exposure to bright white light has been shown to shift endogenous circadian rhythms. Timed exposure to bright light has therefore been used to "reset" the clocks of individuals whose sleep-wake cycles are disturbed. This treatment can be used to treat various insomnia complaints: bright light shown in the evening hours can delay circadian rhythms and lengthen the sleep of insomniacs with complaints of early morning awakening (10). In elderly subjects with age-related sleep maintenance insomnia, timed exposure to bright light has been shown to result in a significantly reduced number of arousals during sleep--giving rise to improved sleep efficiency and quality of sleep (10). In cases where a patient's insomnia complaints can be traced to a breathingrelated sleep disorder, the treatment of choice is usually an assisted ventilation device (e.g., continuous positive airway pressure [CPAP]). These devices are masks won] over the mouth and nose to

MEDICAL UPDATE FOR PSYCHIATRISTS

provide positive airway pressure, thus keeping the airways open during sleep. Pressure levels must be titrated individually for each patient to ascertain the correct pressure needed to suppress apneas. This adjustment is done most effectively in a sleep lab. For this reas o n - a n d because assisted ventilation devices are not usually prescribed without a positive diagnostic polysomnogram--any cases of suspected sleep apnea or other breathing-related sleep disorder should be referred to a sleep specialist or sleep disorder center for appropriate evaluation. When pharmaeotherapy is considered to be the sole option or an adjuvant to behavioral treatment, it is preferable to choose one that has minimal effects on sleep architecture. It should be noted as well that substantial differences exist in medications recommended for temporary and persistent insomnia (11). Examples of first-line pharmacologic therapies for temporary insomnia include triazolom (Halcion), zolpidem (Ambien), and estazolam (Prosom). The provider should encourage the patient to call the next day to report on sleep after initiating a new therapy. If the patient complains of awakening early in the morning, for example, a longer-acting medication may work better, such as temazepam (Restoril), quazepam (Doral), or flurazepam (Dalmane). Caution should be exercised when using hypnotics in the elderly. Drugs, particularly benzodiazepines with long half-lives, may, cause excessive daytime sedation and increase the risk of hip fracture in this population (12). Table 4 lists characteristics of selected hypnotic agents (13).

Treatment for persistent insomnia differs f~oln that for temporary insomnia, because most hypnotics are not indicated for chronic sleep disturbances. Nonpharmaeologic interventions should be emphasized. Nevertheless, some patients will require chronic hypnotic administration. Sedatives and hypnotics are available which have low addictive potential. The short duration of sedation associated with the antihistamines diphenhydramine (Benadryl, 25-50 rag) and hydroxyzine (Vistaril and Atarax, 25-50 rag) makes them useful for patients who have difficulty falling asleep. Low doses of antidepressants such as trazadone (Desyrel, 25-100 rag) or doxepin (Sinequan, 25-75 mg) are helpful in initial and middle insomnia. Two agents with mild to moderate addictive potential, chloral hydrate (Noetee, 500-1000 mg) and Zolpidem (Ambien, 5-10 rag), may also be considered in selected patients with initial and middle insomnia. The hormone melatonin should now also be included in a review of sleep agents marketed as a dietary supplement. Melatonin use has increased, and physicians are facing numerous questions about it. The Medical Letter carried an excellent review of melatonin in 1995 (14). Two small placebo-controlled studies of melatonin used to prevent jet lag in international travel were positive, and another was equivocal. Three small studies of the effect of melatonin on sleep showed a decrease in time to sleep with no adverse effects reported. Clearly more studies of this medication are required. In addition, given poor regulation of dietary supple-

Table 4. Pharmacologic Therapy for Temporary Insomnia*: Benzodiazepines

Drug

Duration

Onset of Action

Triazolam (Haleion) Zolpidem (Ambien) Oxazepam (Serax) Estrazolam (ProSom) Lorazepam (Ativan) Temazepan (Restoril) Clonazepam (Klonopin) Diazepam (Valinm) Flurazepam (Dalmane) Quazepam (Doral)

Short Short Short to intermediate Intermediate Intermediate Intermediate Long Long Long Long

Intermediate Rapid Intermediate to slow Rapid to intermediate Intermediate Intermediate to slow Intermediate Rapid Rapid to Intermediate Rapid

* When the sleep disorder is caused by another medical or psychiatric condition, the primao, treatment should be focused on the underling conditions. Treatment for insomnia should begin x~dth behaxdoral therapies.

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ments, the purity of products is unknown; therefore, we cannot recommend treatment with melatonin at this time. It should be noted that use of nonaddictive medications can compromise a patient's sense of control over his sleep. Psychological dependence on sleep aids can result. Behavioral analysis of the sleep problem and nonpharmacologie treatment can often bring about immediate improvement without the potential long-term complications of pharmacologic treatment. When to Refer to a Sleep Specialist A good general rule of thumb is to refer when a suspected underlying or comerbid medical or neurologic disorder is suspected or must be ruled out. Examples of such conditions are listed in Table 2. In addition, many psychiatrists unfamiliar with evaluation and management of a variety of sleep disorders may choose to refer to a sleep specialist. However, psychiatrists can and do evaluate sleep complaints with polysomnography and treat such conditions using both medications and nonpharmacologic behavioral techniques. Patients should receive a polysomnogram in the following clinical situations: 1) when sleep apnea is suspected; 2) when a sleep-related behavioral disturbance is reported (e.g., to rule out REM behavior disorder); and 3) when treatmentrefractory insomnia is suspected.

Sumnlaru Insomnia is a common medical problem seen in all patient populations and by allphysicians. The incidence of insomnia, particularly in older populations, appears to be increasing. Because patients with psychiatric illness are at more risk for developing insomnia than the general population, psychiatrists need to be able to diagnose, treat, and make appropriate referrals to sleep specialists. An important aspect of the clinical management of insomnia is patient education (i.e., sleep hygiene principles). The pharmacotherapy of insomnia differs for temporary and for persistent insomnia.

7. 8.

9.

10.

References 1. Nicassio PM, Pate JK, Mendlowitz DR, Woodward N. Insomnia: Nonpharmacologic management by private practice physicians. So Med J 1985;78:556-560. 2. Mellinger GD, Balter MG, Uhlenhuth EH. Insomnia and its treatment: Prevalence and correlates. Arch Gen Psych 1985; 42:225-232. 3. Gillin JC, ByerlyWF. The diagnosis and management of insomnia. N Engl J Med 1991;322:239-248. 4. American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 1994, 4th edition. Washington, DC. 5. Edinger JD, Erwin CW. Common sleep disorders: Overview of diagnosis and treatment. Clin Rev 1992;November/ December:60-88. 6. Buysse DJ, Reynolds GF, Kupfer DJ, Thorpy Mj, Bixler E, Manffedi R,

187

11.

12.

13. 14. 15.

Kales A, Vgontzas A, Stepanski E, Roth T, Hauri P, Mesiano D. Clinical diagnoses in 216 insomnia patients using the International Classification of Sleep Disorders (ICSD), DSM-IV and ICD10 Categories: A report from the APA/ NIMH DSM-IV field trial. Sleep 1993; 17:630-637. Rakel RE. Insomnia: Concerns of the family physician. J Faro Pract 1993; 36:551-558. Morin CM, Kowateh RA, Wade JB. Behavioral management of sleep disturbances secondary to chronic pain. J Behay Ther Exp Psychiatry 1989;20:295302. Morin CM, Azrin NH. Behavioral and cognitive treatments of geriatric insomnia. J Consult Clin Psychol 1988; 56:748-753. Buysse DJ, Morin CM, Reynolds CF. Sleep disorders. In: Treatments of Psychiatric Disorders. 2nd edition. Gabbard, GO, ed. Vol. 2. Washington, DC: American Psychiatric Press, 1995:2397-2445. Proceedings from the 1983 Consensus Development Conference on Drugs and Insomnia. Drugs and insomnia: the use of medications to promote sleep. ]AMA 1984;251:2410-2414. Ray WA, Griffin MR, Downey W. Benzodiazepines of long and short elimination half-life and the risk of hip fracture. JAMA 1989;262:3303-3307. Abramowitz M (ed). Hypnotic drugs. The Medical Letter 1996;38:59-61. Abramowitz M (ed). Melatonin. The Medical Letter 1995;37:111-112. Bootzin RR, Nicassio P. Behavioral treatment of insomnia. In: Progress in Behavior Modificatior~. Vol. 6. Hersen M, Eister R, Miller P, eds. New York: Academic Press; 1978:1-45.