Sleep Disorders

Introduction

The light from the moon casts long shadows across your bedroom wall. Your spouse breathes softly beside you. You are wide awake once again at four a.m. Your frustration grows the longer you lie awake. You wonder how you will be able to function at work tomorrow with so little rest.

What is it?

Sleep disorders can be temporary or long-term problems and can affect the quantity or quality of sleep achieved. There are four recognized types of sleeping disorders:

  • Extrinsic sleep disorders, caused by something outside of the body such as drug use or a poor sleep environment
  • Intrinsic sleep disorders, caused by something within the body such as a physical or psychological ailment
  • Circadian rhythm sleep disorders, which are disruptions in your regular daily biological clock such as jet lag or work shift changes
  • Parasomnias, characterized by unusual physical occurrences during sleep such as sleepwalking, grinding teeth or bed-wetting

Insomnia, or difficulty falling asleep, can be caused by any one of the four types of sleep disorders mentioned above.

The National Institutes of Mental Health has identified three broad categories of insomnia. These include:

  • Transient - insomnia lasting fewer than three days
  • Short-term - lasting three days to three weeks
  • Chronic - lasting more than three weeks

What causes it?

There are many elements about the mechanisms of sleep and wakefulness that scientists do not understand. What is known is that sleep is primarily controlled by two systems in the brain: one that induces sleep, and sleep-related processes, and one that regulates sleep within a 24-hour cycle. This cycle, which corresponds to periods of light and darkness, is known as the circadian rhythm cycle. Researchers are discovering that this cycle a process controlled by genes that are found in living creatures ranging from the lowly fruit fly to human beings.

Researchers know that as human beings we go through a variety of stages that can be measured by brain wave patterns. This includes a stage in which our eyes move rapidly, where it is assumed we are dreaming. This stage of sleep is therefore known as rapid eye movement (REM) sleep. Sleep disorders result from either internal abnormalities or external disturbances to these cycles. The feeling of having had enough sleep, or sleep satiety, is related to whether one has gone through all of the cycles of sleep, including both dreamless and REM sleep. We cycle through these stages multiple times per night.

The ongoing study of sleep disorders spans many medical fields, including neuroscience, genetics, physiology and psychology. Some of the mechanisms that play a role in sleep disorders are the subject of study at The National Center for Sleep Disorders Research. This center is situated within the National Heart, Lung, and Blood Institute - part of the National Institutes of Health (NIH) in Bethesda, Maryland. Research includes the study of the genes that play a role in narcolepsy (a condition characterized by brief attacks of deep sleep), how sleep disturbances affect the immune system, and the role of sleep/wake cycles in triggering heart attacks.

Who has it?

Insomnia is the most prevalent sleep complaint among adults in America. Sleep apnea, a disruption of breathing during sleep, affects nearly 12 million people in the U.S. More than one billion dollars are spent each year on sleep medications in the United States.

What are the risk factors?

Most short-term sleep disorders are caused by one or more of the following factors:

  • lifestyle changes, such as marriage or retirement
  • stressful situations, such as the death of a loved one or job pressure
  • physical disorders
  • environment

Chronic sleep disorders have numerous possible causes. These include:

  • medical conditions - especially those producing pain
  • psychiatric conditions such as depression
  • drug use (including alcohol, nicotine, or caffeine)
  • environments that are not conducive to sleep

Many conditions that cause sleep disorders are associated with the elderly, which could explain why insomnia is 1.5 times more common in people older than age 65. In addition to physical conditions that disrupt sleep, elderly people tend to experience changes in sleep patterns leading to fewer hours of quality sleep per night.

Women, especially those who are postmenopausal, are more likely to suffer from sleep disorders than men. However, laboratory studies show that men are more likely to experience disrupted sleep patterns than women.

What are the symptoms?

The symptoms of sleep disorders include:

  • difficulty or inability to fall asleep
  • awaking early from sleep
  • easy disruption of sleep
  • fatigue or sleepiness
  • anxiety
  • lack of concentration
  • irritability

How is it treated?

Drug therapy in combination with good sleep hygiene (click on the Helping Yourself box) may be helpful for short-term management of insomnia.

Over-the-counter sleep aids that contain diphenhydramine (Benadryl), an antihistamine, may be helpful for short-term bouts of insomnia. Because the body can grow accustomed to antihistamine sleep aids, they often lose their effectiveness the more you take them. If you experience continued bouts of insomnia you should talk to your doctor to see if prescription medications are needed. Benzodiazepines are commonly used for the management of sleep disorders. Short-acting benzodiazepines are less likely than long-acting benzodiazepines to be associated with drowsiness or sluggishness the next morning. Benzodiazepines are only available with a prescription. They are controlled substances and do carry a potential for addiction if used inappropriately.

Other drugs used in the management of insomnia include unique agents called non-benzodiazepine sedative hypnotics. Examples include Ambien (zolpidem), Sonata (zaleplon), and Lunesta (eszopiclone).

Drug classes also considered sedative hypnotics are barbiturates and sedating antihistamines. The non-benzodiazepines and barbiturates are also controlled substances due to the potential for addiction.

A new class of sedative hypnotics has recently been introduced to the market. Rozerem (ramelteon),is a melatonin receptor agonist which mimics the body?s natural sleep promoting hormone, melatonin. This drug class is unique because it works with the body?s natural circadian rhythm to promote sleep. These melatonin receptor agonists do not carry an addiction potential.

Natural remedies have been used for years to treat sleep disorders. One of the most popular "natural" remedies for insomnia has been melatonin, which can be obtained at most pharmacies and health food stores. Melatonin is a hormone that is known to be involved in the regulation of sleep and wakefulness. It has been shown that the ingestion of melatonin prior to bedtime will help individuals fall asleep. However, scientific data have failed to confirm that melatonin is useful in maintaining sleep.

Herbal products such as valerian, chamomile, kava kava, and others have also been promoted as natural remedies for insomnia. However, the effectiveness and safety of these products has not been documented in large clinical trials.

Helping Yourself

If you are feeling sleep-deprived, you can do many simple things to improve your chances of getting a good night's rest. These include the following:

  • Proper sleep hygiene: maintain a regular sleep schedule, go to bed and get up at regular times each day--even on weekends.
  • Provide an atmosphere that is conducive to sleep by keeping your bedroom dark and quiet. Set the room temperature at a comfortable level.
  • Limit television viewing in the bedroom only use the bed for sleep and sex.Reduce or eliminate caffeine, tobacco, and alcohol use in the four to six hours before bedtime.
  • Exercise regularly but not just before retiring for the evening.
  • Don't nap later than 3 p.m.
  • Wind down in the 30 minutes before bedtime with a relaxing pre-sleep ritual such as a warm bath, soft music, or reading.
  • If you can't sleep, don't spend your time in bed worrying about the sleep you're losing. Instead, get up and perform an activity until you feel you can sleep again. Some experts recommend that performing an activity that you dislike will help your body want to go to sleep.
  • See a physician if your insomnia lasts longer than a few days.

    What is on the horizon?

    Research has been focused on the combination of drug treatments and therapist ? guided education. Researchers have found that patients, who are treated with both drugs and cognitive-behavioral therapy, were able to maintain improvements in their sleep habits for a longer period of time.

    Researchers at Rush-Presbyterian-St. Luke's Medical Center in Chicago have been conducting studies to determine the cause of delayed sleep phase syndrome (DSPS), a disorder that affects several million Americans. People afflicted with DSPS can't fall asleep until several hours after their preferred bedtime. They have difficulty waking up in the morning to begin normal activities. DSPS is a disorder of the circadian rhythm, indicating it's caused by a malfunction within the body's internal 24-hour clock. The researchers' aim is to lay the foundation to determine what factors -- behavioral, psychological, sociological -- influence the cause of DSPS. Researchers at the University of California, San Francisco are proposing that there are specific genes that cause this syndrome. The long term research goals are to find and identify these genes so that appropriate therapies can be developed.

    References

    American Insomnia Association. Available at: http://www.americaninsomniaassociation.org/medications.htm Accessed March 2006.

    Jackson CS and Curtis JL. Sleep Disorders. In: Pharmacotherapy: A Pathophysiologic Approach 6th Edition. McGraw-Hill:New York 2005. pg 1321-1332.

    Meadows M. How Well Are You Sleeping? U.S. Food and Drug Administration. Available at: http://www.fda.gov/fdac/features/2002/602_sleep.html Accessed March 2006.

    National Institutes of Health National Center on Sleep Disorders Research website. Available at: http://rover2.nhlbi.nih.gov/about/ncsdr/ Accessed March 2006.

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    Brzezinski A. Melatonin in humans. New England Journal of Medicine 1997. 336(3):186-95

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    Roth T, Seiden D, Zee P, et al. Phase III outpatient trial of ramelteon for the treatment of chronic insomnia in elderly patients [abstract no A21]. J Am Geriatr Soc 2005; 53 (4 Suppl.): S25

    Mendelson W. Jain B. An assessment of short-acting hypnotics. Drug Safety 1995;13(4):257-70.

    Pray W. Help for the patient with insomnia. US Pharmacist 1996;21(7):18-30.

    Ruddy J. Diagnosing and treating sleep disorders. Medical/Scientific Update. 1993;11(4). National JewishMedical and Research Center

    Simon G. VonKorff M. Prevalence, burden, and treatment of insomnia in primary care. American Journal of Psychiatry 1997;154(10):1417-23.

    SleepNet's Guide to Sleep Disorders. SleepNet. Available at: http://www.sleepnet.com/disorder.htm Accessed March 2006 NIH State-of-the-Science Conference Statement on Manifestations and Management of Chronic Insomnia in Adults. National Institutes of Health Consensus Statement. Available at: http://consensus.nih.gov/2005/2005InsomniaSOS026html.htm Accessed March 2006

    Fu & Ptaeek Laboratories, The University of California, San Francisco Department of Neurology Copyright ? 2004-2006 The Regents of the University of California. http://ucsf.edu/humgene/dsps.htm

    Sleep Disorders Health Condition Last Updated: October 2007

    Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It is not intended to diagnose a health condition, but it can be used as a guide to help you decide if you should seek professional treatment or to help you learn more about your condition once it has been diagnosed.

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