Nightmare disorder, which is also called dream anxiety disorder, is characterized by the occurrence of repeated dreams during which the sleeper feels threatened and frightened. The sense of fear causes the person to awake.
Nightmares are dreams that cause intense fear. These dreams are often complex and fairly long. During the dream, the sleeper usually encounters or experiences a threat to their life or safety. Nightmares are also reported that do not involve physical danger.
As the dream progresses, the threat to the person usually increases, as does their sense of fear. Waking usually occurs just as the threat or danger reaches its climax. It is often difficult for a person to return to sleep after waking from a nightmare. Nightmares usually occur during the second half of the night's sleep.
Causes and symptoms
During the course of a nightmare the sleeper may moan, talk, or move slightly, although these signs do not always appear. The person wakes from the nightmare with a profound sense of fear. Waking is complete, and usually accompanied by increased heart rate, sweating, and other symptoms of anxiety or fear. Once fully awake, the person usually has a good recall of the dream and what was so frightening about it. Because of the physical symptoms of anxiety and because clarity is achieved immediately upon waking, returning to sleep after a nightmare is often difficult. The vividness of the recall and the prominence of the dream images in the person's mind can also make it difficult to calm down and return to sleep.
Sometimes people may avoid going to sleep after a particularly intense nightmare because of the fear of having another bad dream. In addition, people may have problems falling asleep if they are experiencing anxiety caused by the fear of having nightmares. As a result, these people may have the signs and symptoms associated with mild sleep deprivation, such as decreased mental clarity, problems paying attention, excessive daytime sleepiness, irritability, or mild depression.
The causes of nightmares are not known for certain. Adults who have nightmares on a regular basis are a small minority of the American population. About half of these people are thought to suffer from psychiatric disorders that cause the nightmares. Nightmares may also be triggered by major psychological traumas, such as those experienced by patients with post-traumatic stress disorder . For most patients who do not have an underlying mental disorder, the nightmares are attributed to stress. Nightmares that occur on an irregular and occasional basis are usually attributed to life stressors and associated anxiety.
Some researchers think that artistic or creative people are at greater risk for nightmares, as are people who are generally sensitive. These people are considered to have well-developed imaginations and are very sensitive to environmental and social factors.
Nightmares can be a side effect of some medications or drugs of abuse, including drugs given for high blood pressure; levodopa and other drugs given to treat Parkinson's disease; amphetamines , cocaine, and other stimulants; and some antidepressants. Withdrawal from alcohol and other medications can also sometimes cause nightmares.
The actual percentage of people that suffer from nightmare disorder is not known, as many people do not seek treatment for it. There are, however, estimates of the proportion of the population that experience occasional nightmares. Many children suffer from nightmares that concern their parents. Estimates on the number of children who have recurrent nightmares range from 10–50%. In children, however, nightmares are not usually associated with psychiatric illness.
The number of children experiencing nightmares decreases as they get older. More than 3% of young adults have frequent nightmares, but only about 1% of mature adults experience nightmares once or twice a week. Half of the adults in the United States who experience regular nightmares have diagnosable psychiatric illnesses. Women are estimated to have nightmares two to four times more frequently than men. There is some uncertainty as to whether this figure reflects an actual difference between the sexes in the frequency of nightmares, or whether women are simply more likely than men to report nightmares. Nightmares typically decrease in frequency as people grow older.
A diagnosis of nightmare disorder is usually made because the person reports the problem to their family physician or a psychiatrist . There are no laboratory tests for nightmare disorder, although the doctor may give the patient a physical examination to rule out any medical conditions that may be causing anxiety or stress.
Nightmares are characterized by awakening with a sense of fear, a clear recollection of the dream, and physical symptoms of anxiety. Nightmares can occur during nighttime sleep or daytime naps. A patient experiencing nightmares must meet the criteria listed in the Diagnostic and Statistical Manual of Mental Disorders to be diagnosed with nightmare disorder. The manual, which provides guidelines used by the American Psychiatric Association for diagnosing psychiatric disturbances, gives four distinct criteria:
- • The patient must experience repeated awakenings from frightening dreams.
- • When the patient awakes, he or she must wake fully and be aware of his or her surroundings.
- • The nightmares must cause the patient distress in important areas of his or her life.
- • The nightmares cannot be directly attributed to another disorder, or be the direct effects of medications, substance abuse, or a medical condition.
Nightmare disorder can be confused with sleep terror disorder . Both disorders are characterized by an arousal during sleep when the patient shows symptoms of anxiety or fear. Sleep terror, however, is characterized by a partial arousal from sleep during which the patient is generally nonresponsive. After a nightmare, the patient becomes fully awake and is aware of his or her surroundings. During an episode of sleep terror, a patient often gets out of bed and is active, and often screams or cries. During a nightmare, the patient may move slightly or moan but does not display such dramatic or active symptoms. Patients do not remember either the sleep terror episode or what caused the fear, but patients who have nightmares remember them with great clarity and often in considerable detail. Such symptoms of fear or anxiety as increased heart rate, dilated pupils, and sweating are not as dramatic in patients with nightmare disorder as they are in patients experiencing sleep terrors.
Nightmares that are associated with a psychiatric disorder are managed by treating the underlying disorder. For patients without psychiatric disorders, psychological counseling to deal with any recurring themes in the nightmares may be helpful. Children may not require treatment for nightmares unless the dreams are causing significant distress, as nightmares generally resolve as children mature.
Because stress is thought to be the most common cause of nightmares, stress reduction techniques may prove to be effective complementary treatments. Typical relaxation techniques such as yoga , meditation , or exercise may be helpful. Psychotherapy can be an effective way to identify major stressors in the person's life, and to explore ways in which they may be reduced or eliminated.
Nightmare disorder can be a lifelong disorder. A general improvement in symptoms often takes place, however, as the patient gets older. Treatment for any underlying psychological disorders can be very successful.
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Chokroverty, Susan, ed. Sleep Disorders Medicine: Basic Science, Technical Considerations, and Clinical Aspects. 2nd ed. Boston: Butterworth-Heinemann, 1999.
Sadock, Benjamin J., and Virginia A. Sadock, eds. Comprehensive Textbook of Psychiatry. 7th ed. Vol. 2. Philadelphia: Lippincott Williams and Wilkins, 2000.
Krakow, Barry, and others. "Imagery Rehearsal Therapy for Chronic Nightmares in Sexual Assault Survivors with Posttraumatic Stress Disorder." Journal of the American Medical Association 286, no. 5 (August 1 2001).
American Academy of Sleep Medicine. 6301 Bandel Road NW, Suite 101, Rochester, MN 55901. (507) 287-6006. <www.asda.org> .
Tish Davidson, A.M.