6.
Sleepiness In Your Patient

For all people, sleepiness is physiologically regulated by two primary processes:

	The body's circadian rhythm causes an increase in sleepiness twice during a 24- hour period (in general, between midnight and 7 a.m. and in the midafternoon between 1 p.m. and 4 p.m.); and
	The physiological need for sleep, which is increased by sleep loss and sleep disruption.

The need for sleep and the circadian rhythm interact to determine the level of sleepiness and alertness.¹¹ People with disturbances of either of these sleep-regulating mechanisms can exhibit problem sleepiness, with the most common causes being primary sleep disorders, other medical conditions that disrupt sleep, drugs, and lifestyle.

Primary Sleep Disorders

Obstructive Sleep Apnea — Obstructive sleep apnea, a potentially life-threatening disorder, is produced by the narrowing or collapse of the upper airway during sleep that restricts or prevents breathing.¹² Repeated episodes of airway collapse throughout the night disrupt and fragment sleep and may produce hypoxemia and other cardiovascular stress. Sleep apnea has been suspected of contributing to myocardial ischemia and myocardial infarction in patients with coronary artery disease.¹³ Sleep apnea is seen in approximately 4 percent of middle-age men and 2 percent of middle-age women.¹⁴ The prevalence of sleep apnea is even higher among the elderly.¹⁵ Symptoms of obstructive sleep apnea include chronic, loud snoring; gasping or choking episodes during sleep; excessive daytime sleepiness; drowsy driving; automobile or work-related accidents; and personality changes or cognitive difficulties. Signs of possible obstructive sleep apnea are obesity, a thick neck, systemic hypertension, and nasopharyngeal narrowing. The diagnosis of obstructive sleep apnea is confirmed by polysomnography. The severity of symptoms dictates the urgency for testing.

Insomnia — Patients with insomnia complain that sleep is difficult to initiate or maintain, or that it is neither refreshing nor restorative.^4,16 Insomnia is the most prevalent sleep-related complaint; approximately 30 percent of American adults report occasional insomnia, and nearly 10 percent report chronic insomnia.^4,17 Women report insomnia more frequently than do men,^4,18,19 and insomnia complaints increase with age.^19,20 Some patients with insomnia have problem sleepiness. ^17,21

Insomnia is classified by the duration of symptoms. Acute insomnia is usually the result of a stressful life event or change in sleep environment or sleep schedule. Chronic insomnia may result from medical conditions, psychiatric disorders, or other causes.⁴ Thus, a careful sleep history is required for an accurate diagnosis.

Restless Legs Syndrome and Periodic Limb Movements in Sleep — The symptoms of restless legs syndrome are commonly reported and include sensations of creeping, crawling, pulling, or tingling, which cause an irresistible urge to move the legs. These symptoms usually occur prior to sleep onset, making it difficult for the patient to fall asleep. Patients with restless legs syndrome often have coexisting periodic limb movements in sleep. The latter condition is characterized by episodes of repetitive, stereo-typed limb (usually leg) movements occurring during sleep which may disturb the patient or bed partner.²² The limb movements are often associated with partial or complete awakening, although patients are usually unaware of either the movements or the arousals. The prevalence of periodic limb movements in sleep increases with advancing age; as many as one-third of patients older than 60 may have this condition.²³

Patients with restless legs syndrome and periodic limb movements in sleep may have problem sleepiness or nonrefreshing sleep caused by difficulty falling asleep or frequent arousals (partial awakenings that may not be remembered) during the night. The diagnosis of restless legs syndrome is based on history; there is no specific laboratory test. In contrast, periodic limb movements in sleep can be detected by polysomnography.

Narcolepsy — Narcolepsy is a chronic sleep disorder producing severe problem sleepiness. The primary symptoms of narcolepsy are excessive and overwhelming daytime sleepiness, even after adequate nocturnal sleep, and cataplexy, which refers to sudden episodes of muscle weakness triggered by emotional reactions (laughter, anger, or fear). Other classic symptoms of narcolepsy can include sleep paralysis (a temporary inability to talk or move upon falling asleep or awakening) and hypnagogic hallucinations (vivid, frightening, dreamlike experiences that occur while dozing or falling asleep).

Narcolepsy is often misdiagnosed. Symptoms are usually first evident during adolescence and young adulthood, commonly before the third decade of life. Narcolepsy can also occur in children. A definitive diagnosis of narcolepsy usually requires objective testing and evaluation by a sleep specialist.

Other Medical Conditions That Disrupt Sleep

Patients with medical conditions such as chronic bronchitis and asthma have more problems with initiating and maintaining sleep than healthy people do.^24_26 Congestive heart failure patients may have a higher prevalence of periodic limb movements in sleep, with associated arousals, and consequently suffer daytime sleepiness.²⁷ Patients with severe congestive heart failure who also have Cheyne-Stokes respirations suffer sleep fragmentation and nocturnal hypoxemia leading to problem sleepiness.²⁸ Chronically painful conditions such as rheumatoid arthritis, back pain, and sickle cell disease can also disrupt sleep and lead to problem sleepiness.^29_31

Effects of Drugs That Disrupt Sleep

Prescription and over-the-counter drugs, as well as caffeine, alcohol, and nicotine, can have substantial effects on sleep and sleepiness. For example, long-acting benzodiazepines have residual sedative effects that contribute to daytime sleepiness;³²beta-blockers can cause difficulty falling asleep and increase the number of awakenings;³³ and theophylline has been shown to disrupt sleep in some people even at low therapeutic doses.³⁴

Caffeine can fragment sleep. The half-life of caffeine is between 3 and 7 hours, so even coffee consumed during the day may be an important cause of sleeplessness at night and therefore sleepiness the next day.³⁵ While alcohol shortens the time it takes to fall asleep and is often ingested by patients for this reason, it increases sleep disruption in the latter part of the night.³³Nicotine can disrupt sleep and reduce total sleep time. Smokers report significantly more daytime sleepiness and minor accidents than do nonsmokers, especially in younger age groups.

Inadequate Sleep Due to Lifestyle

The need for sleep varies among individuals and, because of this, it is difficult to recommend a specific quantity of sleep for all persons. When adults are allowed to sleep without restriction, the average time slept is 8 to 8.5 hours.^37,38 Chronically obtaining too little sleep can lead to a cumulative sleep debt and problem sleepiness.^39,40 For some patients, problem sleepiness will be resolved when sleep duration is increased. If problem sleepiness is not resolved with added sleep, other causes need to be considered. Prescription and over-the-counter drugs, as well as caffeine, alcohol, and nicotine, can have substantial effects on sleep and sleepiness.

Shift Workers — Approximately 20 to 25 percent of the American work force is engaged in some form of shift work.⁴¹ Most shift workers complain of difficulty falling or staying asleep or problem sleepiness ^42,43 The sleepiness of shift workers is related to both insufficient sleep and the displaced timing of sleep and wakefulness.⁴⁴ The adverse effects of shift work differ among individuals and may vary with age, with younger workers coping better than older ones.⁴⁵
Shift workers are at high risk for motor vehicle crashes; in one study, 20 percent had a traffic accident or a "near miss" in the preceding 12 months because of sleepiness on the drive home from work.⁴⁶ Consequently, shift workers need to be advised about their increased risk for accidents. Because of this vulnerability, it is particularly important to assess the patient for inadequate sleep duration and coexisting sleep disorders, which will magnify the sleepiness caused by shift work.

Adolescents — A significant proportion of young people report symptoms of problem sleepiness that include difficulty with getting up for school, falling asleep in school, or struggling to stay awake while doing homework.⁴⁷ Such symptoms may be the result of inadequate sleep. Adolescents need more sleep than adults do, and for many this is at least 9 hours per night.^48,49 In addition, the circadian timing system may change during pubertal development, resulting in a tendency for adolescents to stay up later and sleep in later.^50_53

  Identification of the Patient With Problem Sleepiness

Patients may underestimate their degree of sleepiness. Questions regarding specific sleep/wake habits and activities, as well as input from family members, can reveal significant signs of problem sleepiness. To assess whether a patient is getting an adequate quantity of sleep, it is best to ask about bedtimes and rising times, because asking how long the patient sleeps is likely to yield an inaccurate estimate. Comparison of sleep quantity on days off versus work days may be helpful. Patients who sleep several hours longer on days off (by sleeping in or napping) may not be getting enough sleep during the work week. They may describe feeling more alert on days off. Table 1 lists sample questions that can be incorporated into the history-taking process to obtain a sleep/wake profile. Accurate diagnosis of specific sleep disorders will require further exploration.

Table 1. Sleep/Wake Profile_Sample Questions

Signs of Sleepiness

	Does the patient report dozing off or difficulty staying awake during routine tasks, especially while driving?
	Does the patient complain of difficulties or accidents at work/school/social activities/ home due to poor attention span?
	Does the patient complain of sleepiness or nonrefreshing sleep, or is sleepiness frequently noted by others?
	Does the patient nap on most days or more often than once a day?

Sleep Disorders

	Does it take the patient more than 30 minutes to fall asleep at night? Are there awakenings during the night? Unwanted early morning waking? [Relates to insomnia.]
	Does the bed partner report that the patient's legs or arms jerk during sleep? [Relates to periodic limb movements in sleep.]
	Does the patient report "creeping, crawling feelings" in the legs? [Relates to restless legs syndrome.]
	Does the patient snore loudly, gasp, choke, or stop breathing during sleep? [Relates to obstructive sleep apnea.]
	Does the patient (or family) describe cataplexy (sudden muscle weakness in response to emotional reactions), hypnagogic hallucinations (vivid, dreamlike experiences while falling asleep or dozing), or sleep paralysis (temporary inability to talk or move upon falling asleep or awakening)? [Relates to narcolepsy.]

Quantity and Quality of Sleep

	Is the patient a shift worker? What are the work hours? Is the patient an adolescent?
	What are the bedtimes and rise times on weekdays and weekends?
	Does the patient use caffeine, tobacco, alcohol, or over-the-counter and prescription medications?
	Is the sleep environment conducive to sleep (relative to noise, interruptions, temperature, light)?
	Does the patient have a medical condition, chronic pain, or other cause of sleep difficulties?

  Management of Problem Sleepiness

Problem sleepiness can occur in any age group. It is not "normal." Direct questions should be asked about inappropriate sleepiness. Family members also may be able to help clarify the situation. Patients need to be aware of the obligatory nature of sleep and its importance for optimal functioning. Because of inattention and inadvertent sleep onsets that can result from sleepiness, it is extremely important to educate the patient about the dangers of driving while sleepy.

Accurate identification of all causes of the individual's problem sleepiness is crucial for effective treatment. For example, an adolescent may have narcolepsy in addition to inadequate sleep, causing problem sleepiness. Similarly, a shift worker may have obstructive sleep apnea in addition to a sleep/wake schedule problem.

All patients, and especially young people, should be advised that preexisting sleepiness heightens the sedative effects of alcohol. Thus, a sleepy individual consuming a small amount of alcohol is much more susceptible to sedation, impaired performance, and automobile crashes than a well-rested one consuming the same amount of alcohol.^54-56 Stimulants do not play a major role in the treatment of problem sleepiness (except for patients with narcolepsy), and they do not substitute for sleep. The regular use of stimulants by patients may be a clue to the existence of an underlying sleep disorder or problem sleepiness.

Primary Sleep Disorders

Sleep disorders are chronic, necessitating long-term management and monitoring of affected patients. Primary care physicians play an important role in case-finding, as well as management of patients with sleep disorders. ⁵⁷ Incorporating a sleep history into the general review of systems can be useful in the initial identification of these patients (see Table 1). Patients with severe symptoms, such as falling asleep while driving, will generally require polysomnography for accurate diagnosis.

For patients with obstructive sleep apnea, treatment options range from behavioral therapies to oral/dental appliances to surgical interventions. Many patients are treated with nasal continuous positive airway pressure (CPAP), in which a mask is worn over the nose during sleep and pressure from an air blower forces air through the nasal passages, preventing airway collapse.

A broad treatment plan for insomnia may include behavioral therapies alone or a combination of behavioral and pharmacological treatments.⁵⁸ Short-term use of short-acting hypnotics has been shown to be effective in reducing problem sleepiness associated with acute insomnia. However, long-term use of hypnotics for insomnia remains controversial. Lower doses of short-acting agents should be prescribed for older patients.⁵⁹ In obstructive sleep apnea, hypnotics are counterproductive and worsen symptoms.

Pharmacotherapy for restless legs syndrome and periodic limb movements in sleep may include benzodiazepines, dopaminergic agents, or opioids. For mild cases of restless legs syndrome, patients may relieve symptoms by massaging the legs, exercising, and eliminating alcohol and caffeine intake. Treatment of narcolepsy includes central nervous system stimulants for excessive daytime sleepiness, as well as anticholinergics and antidepressant agents for cataplexy. Scheduled naps are an important adjunct to drug therapy.

Primary care physicians play an important role in case-finding, as well as management of patients with sleep disorders. Incorporating a sleep history into the general review of systems can be useful in the initial identification of these patients.

Normal sleep is required for optimal functioning. Normal wakefulness should be effortless and free of unintended sleep episodes. Problem sleepiness is common and dangerous and has numerous causes. However, it is generally correctable. The primary care physician is in an ideal position to identify signs and symptoms of problem sleepiness and initiate appropriate care of the patient, including educating the patient about the significant dangers of functioning while impaired by sleepiness.

 

Source:

National Center on Sleep Disorders Research and Office Prevention, Education, and Control National Institutes of Health August 1997

  Where to Get More Information?

National Center on Sleep Disorders Research (NCSDR) The NCSDR supports research, scientist training, dissemination of health information, and other activities on sleep and sleep disorders. The NCSDR also coordinates sleep research activities with other Federal agencies and with public and non-profit organizations. National Center on Sleep Disorders Research National Institutes of Health Two Rockledge Centre Suite 7024 6701 Rockledge Drive, MSC 7920 Bethesda, MD 20892-7920 (301) 435-0199 (301) 480-3451 (fax)

National Heart, Lung, and Blood Institute Information Center The Information Center acquires, analyzes, promotes, maintains, and disseminates programmatic and educational information related to sleep disorders and sleep-disordered breathing. Write for a list of available publications or to order additional copies of this brochure. NHLBI Information Center P.O. Box 30105 Bethesda, MD 20824-0105 (301) 251-1222 (301) 251-1223 (fax) http://www.nhlbi.nih.gov/nhlbi/ nhlbi.htm

References

 

1. Roth T, Roehrs TA, Carskadon MA, Dement WC. Daytime sleepiness and alertness. In: Kryger MH, Roth T, Dement WC, eds. Principles and Practice of Sleep Medicine. Philadelphia: W.B. Saunders, 1994:40-49.

    

2. Knipling RR, Wang J-S. Crashes and Fatalities Related to Driver Drowsiness/Fatigue. Research Note. National Highway Traffic Safety Administration, U.S. Department of Transportation, 1994.

    

3. Findley L, Unverzagt M, Guchu R, Fabrizio M, Buckner J, Suratt P. Vigilance and automobile accidents in patients with sleep apnea or narcolepsy. Chest 1995;108(3):619- 624.

    

4. Costa e Silva JA, Chase M, Sartorius N, Roth T. Special report from a symposium held by the World Health Organization and the World Federation of Sleep Research Societies: an overview of insomnias and related disorders—recognition, epidemiology, and rational management. Sleep 1996;19(5):412-416.

    

5. New York State Task Force on the Impact of Fatigue on Driving. 1994 Telephone Survey on Drowsy Driving: Summary Report. Albany, NY: Institute for Traffic Safety Management and Research, December 1994.

    

6. Pack AI, Pack AM, Rodgman E, Cucchiara A, Dinges DF, Schwab CW. Characteristics of crashes attributed to the driver having fallen asleep. Accid Anal Prev 1995;27(6):769- 775.

    

7. Karni A, Tanne D, Rubenstein BS, Askenasy JJM, Sagi D. Dependence on REM sleep of overnight improvement of a perceptual skill. Science 1994;265:679-682.

    

8. Rotenberg VS. Sleep and memory I: The influence of different sleep stages on memory. Neurosci Biobehav Rev 1992;16:497-502.

    

9. Carskadon MA, Rosekind MR, Galli J, Sohn J, Herman KB, Davis SS. Adolescent sleepiness during sleep restriction in the natural environment. Sleep Res 1989;18:115.

    

10. Dinges DF. An overview of sleepiness and accidents. J Sleep Res 1995;4(Suppl 2):4-14.

     

11. Johnson MP, Duffy JF, Dijk DJ, Ronda JM, Dyal CM, Czeisler CA. Short-term memory, alertness and performance: a reappraisal of their relationship to body temperature. J Sleep Res1992;1:24-29.

     

12. Isono S, Remmers JE. Anatomy and physiology of upper airway obstruction. In: Kryger MH, Roth T, Dement WC, eds. Principles and Practice of Sleep Medicine. Philadelphia: W.B. Saunders, 1994:642-656.

     

13. Hung J, Whitford EG, Parsons RW, Hillman DR. Association of sleep apnoea with myocardial infarction in men. Lancet 1990;336:261-264.

     

14. Young T, Palta M, Dempsey J, Skatrud J, Weber S, Badr S. The occurrence of sleep-disordered breathing among middle-aged adults. N Engl J Med 1993;328(17):1230-1235.

     

15. Ancoli-Israel S, Coy T. Are breathing disturbances in elderly equivalent to sleep apnea syndrome? Sleep 1994;17(1):77-83.

     

16. Kupfer DJ, Reynolds CF III. Management of insomnia. N Engl J Med 1997;336(5):341- 346.

     

17. Gallup Organization. Sleep in America: A National Survey of U.S. Adults. National Sleep Foundation, 1991.

     

18. Radecki SE, Brunton SA. Management of insomnia in office-based practice: national prevalence and therapeutic patterns. Arch Fam Med 1993;2:1129-1134.

     

19. Weyerer S, Dilling H. Prevalence and treatment of insomnia in the community: results from the Upper Bavarian Field Study. Sleep 1991;14(5):392-398.

     

20. Ohayon M. Epidemiological study on insomnia in the general population. Sleep 1996;19(3):S7-S15.

     

21. Gallup Organization. Sleep in America: A National Survey of U.S. Adults. National Sleep Foundation, 1995.

     

22. Montplaisir J, Godbout R, Pelletier G, Warnes H. Restless legs syndrome and periodic limb movements during sleep. In: Kryger MH, Roth T, Dement WC, eds. Principles and Practice of Sleep Medicine. Philadelphia: W.B. Saunders, 1994:589-597.

     

23. Ancoli-Israel S, Kripke DF, Klauber MR, Mason WJ, Fell R, Kaplan O. Periodic limb movements in sleep in community-dwelling elderly. Sleep 1991;14(6):496-500.

     

24. Kinsman RA, Yaroush RA, Fernandez E, Dirks JF, Schocket M, Fukuhara J. Symptoms and experiences in chronic bronchitis and emphysema. Chest 1983;83(5):755-761.

     

25. Klink M, Quan SF. Prevalence of reported sleep disturbances in a general adult population and their relationship to obstructive airways diseases. Chest 1987;91(4):540-546.

     

26. Janson C, Gislason T, Boman G, Hetta J, Roos B-E. Sleep disturbances in patients with asthma. Respir Med 1990;84:37-42.

     

27. Hanly PJ, Zuberi-Khokhar N. Periodic limb movements during sleep in patients with congestive heart failure. Chest 1996;109(6):1497-1502.

     

28. Hanly P, Zuberi-Khokhar N. Daytime sleepiness in patients with congestive heart failure and Cheyne-Stokes respiration. Chest 1995;107(4):952-958.

     

29. Hirsch M, Carlander B, Vergé M, et al. Objective and subjective sleep disturbances in patients with rheumatoid arthritis. A reappraisal. Arthritis Rheum 1994;37(1):41-49.

     

30. Louis Harris & Associates, Inc. Sleepiness, Pain and the Workplace. National Sleep Foundation, 1997.

     

31. Shapiro BS, Dinges DF, Orne EC, et al. Home management of sickle cell-related pain in children and adolescents: natural history and impact on school attendance. Pain 1995;61:139-144.

     

32. Balter MB, Uhlenhuth EH. The beneficial and adverse effects of hypnotics. J Clin Psychiatry 1991;52(Suppl 7):16-23.

     

33. Nicholson AN, Bradley CM, Pascoe PA. Medications: effect on sleep and wakefulness. In: Kryger MH, Roth T, Dement WC, eds. Principles and Practice of Sleep Medicine. Philadelphia: W.B. Saunders, 1994:364-371.

     

34. Roehrs T, Merlotti L, Halpin D, Rosenthal L, Roth T. Effects of theo-phylline on nocturnal sleep and daytime sleepiness/alertness. Chest 1995;108(2):382-387.

     

35. Stradling JR. Recreational drugs and sleep. In: Shapiro CM, ed. ABC of Sleep Disorders. London: BMJ Publishing Group, 1993:74-76.

     

36. Phillips BA, Danner FJ. Cigarette smoking and sleep disturbance. Arch Intern Med 1995;155:734- 737.

     

37. Roehrs TA, Timms V, Zwyghuizen-Doorenbos A, Roth T. Sleep extension in sleepy and alert normals. Sleep 1989;12:449-457.

     

38. Wehr TA, Moul DE, Barbato G, et al. Conservation of photoperiod-responsive mechanisms in humans. Am J Physiol 1993;265:R846-R857.

     

39. Carskadon MA, Dement WC. Cumulative effects of sleep restriction on daytime sleepiness. Psychophysiology 1981;18:107-113..

     

40. Dinges DF, Pack F, Williams, K, et al. Cumulative sleepiness, mood disturbance, and psychomotor vigilance performance decrements during a week of sleep restricted to 4-5 hours per night. Sleep 997;20(4):267-277.

     

41. U.S. Congress, Office of Technology Assessment. Biological Rhythms:Implications for the Worker. Washington, DC: U.S. Government Printing Office, September 1991; OTA- BA-463.

     

42. Rutenfranz J, Haider M, Koller M. Occupational health measures for night workers and shift workers. In: Folkard S, Monk T, eds. Hours of Work: Temporal Factors in Work Scheduling. New York: John Wiley & Sons, 1985:199-210.

     

43. Åkerstedt T, Gillberg M. The circadian variation of experimentally displaced sleep. Sleep 1981;4(2):159-169.

     

44. Monk TH, Folkard S, Wedderburn AI. Maintaining safety and high performance on shiftwork. Appl Ergonomics 1996;27(1):17-23.

     

45. Härmä M. Sleepiness and shiftwork: individual differences. J Sleep Res 1995;4(Suppl 2):57-61.

     

46. Richardson GS, Minor JD, Czeisler CA. Impaired driving performance in shiftworkers: the role of the circadian system in a multifactorial mode. Alcohol, Drugs and Driving 1990;5(4) and 6(1):265-273.

     

47. Carskadon MA, Mancuso J, Rosekind MR. Impact of part-time employment on adolescent sleep patterns. Sleep Res 1989;18:114.

     

48. Carskadon MA. Patterns of sleep and sleepiness in adolescents. Pediatrician 1990;17:5- 12.

     

49. Yarcheski A, Mahon NE. A study of sleep during adolescence. J Pediatr Nurs 1994;9(6):357-367.

     

50. Yshihara K, Honma Y, Miyake S. Investigation of the children's version of the morningness- eveningness questionnaire with primary and junior high school pupils in Japan. Percept Mot Skills 1990;71:1353-1354.

     

51. Andrade MM, Benedito-Silva AA, Menna-Barreto L. Correlations between morningness- eveningness character, sleep habits and temperature rhythm in adolescents. Braz J Med Biol Res 1992;25:835-839.

     

52. Carskadon MA, Vieira C, Acebo C. Association between puberty and delayed phase preference. Sleep 1993;16(3):258-262.

     

53. Carskadon MA, Richardson GS, Tate BA, Acebo C. Long nights protocol:access to circadian parameters in adolescents (abstract). Paper presented at the Fifth Meeting of the Society for Research on Biological Rhythms, Amelia Island Plantation, May 9, 1996.

     

54. Roehrs T, Zwyghuizen-Doorenbos A, Knox M, Moskowitz H, Roth T. Sedating effects of ethanol and time of drinking. Alcohol Clin Exp Res 1992;16(3):553-557.

     

55. Roehrs T, Beare D, Zorick F, Roth T. Sleepiness and ethanol effects on simulated driving. Alcohol Clin Exp Res 1994;18(1):154-158.

     

56. Zwyghuizen-Doorenbos A, Roehrs T, Timms V, Roth T. Individual differences in the sedating effects of ethanol. Alcohol Clin Exp Res 1990;14(3):400-404.

     

57. Ball EM, Simon RD Jr, Tall AA, Banks MB, Nino-Murcia G, Dement WC. Diagnosis and treatment of sleep apnea within the community: the Walla Walla project. Arch Intern Med 1997;157:419-424.

     

58. Morin CM, Wooten V. Psychological and pharmacological approaches to treating insomnia: critical issues in assessing their separate and combined effects. Clin Psychol Rev 1996;16(6):521-542.

     

59. Nicholson AN. Hypnotics: Clinical pharmacology and therapeutics. In: Kryger MH, Roth T, Dement WC, eds. Principles and Practice of Sleep Medicine. Philadelphia: W.B. Saunders, 1994:355-363.

 

Problem Sleepiness in Your Patient Working Group Members David Dinges, Ph.D. (Chair) Associate Professor of Psychologyin Psychiatry Chief, Division of Sleep and Chronobiology Director, Unit for Experimental Psychiatry Department of Psychiatry University of Pennsylvania School of Medicine Philadelphia, Pennsylvania Eric Ball, M.D. Chairman, Department of Medicine Walla Walla Clinic Walla Walla, WA Paul Fredrickson, M.D. Chariman, Psychiatry, Psychology, and Sleep Disorders Clinic Mayo Clinic Jacksonville, FL Meir Kryger, M.D. Professor of Medicine St. Boniface Hospital Winnipeg, MB Gary Richardson, M.D. Assisstant Professor of Medicine Neurobiology Laboratroy, Department of Medicine Miriam Hospital and Brown University School of Medicine Providence, RI Stephen Sheldon, D.O. Assisstant Professor of Pediatrics Northwestern University Medical School Director, Sleep Medicine Center Children's Memorial Hospital Chicago, IL Virgil Wooten, M.D. Professor of Medicine and Psychiatry Sleep Disorders Center Eastern Virginia Medical School Norfold, VA

Bill Zepf, M.D. Assisstant Professor of Family Medicine Georgetown University School of Medicine Medical Director Fort Lincoln Family Medical Center Colmar Manor, MD NHLBI Staff James Kiley, Ph.D. Director, National Center on Sleep Disorders Research National Heart, Lung and Blood Institute National Institutes of Health Bethesda, MD Susan Rogus, R.N., M.S Coordinator, Sleep Education Activities National Heart, Lung and Blood Institute National Institutes of Health Bethesda, MD Support Staff Susan Shero, R.N., M.S. Program Manager R.O.W. Sciences, Inc. Rockville, MD