Panic disorder.

Panic disorder is a subtype of anxiety manifested by discrete periods of apprehension or fear and at least four of the following somatic symptoms: dyspnea, palpitations, chest pain, choking, dizziness, depersonalization or derealization experience, paresthesias, hot and cold flashes, sweating, faintness, trembling, and fear of dying, going crazy, or doing something uncontrolled during an attack. Because the patient with panic disorder often selectively focuses on one of these somatic symptoms and may minimize or deny psychosocial distress, panic disorder is frequently misdiagnosed. As a result of the frightening nature of the symptoms, a pattern of overutilization of medical care systems frequently ensues. Panic disorder is usually precipitated by stressful life events, most commonly separation or loss, in a patient with a genetic or acquired vulnerability. As with other psychophysiologic illness (depression, duodenal ulcer) resolution of the acute stressful life event may not lead to resolutions of the physiologic changes. Two specific tricyclic antidepressants, imipramine and desipramine, have been shown to be effective therapeutic agents in treating panic disorder.