Panic Disorder is characterized by recurrent panic attacks (or, sudden rushes of intense fear or discomfort). A panic attack is defined by a cluster of physical and cognitive symptoms, including heart palpitations, shortness of breath, feelings of unreality, and fears of dying, going insane, or losing control. Panic attacks are common to all anxiety disorders, however, panic disorder is distinguished by unexpected attacks, that is, attacks that occur without an obvious trigger, and at least one month of persistent apprehension about the recurrence of panic or its consequences, or a significant behavioral change.
Agoraphobia refers to avoidance or endurance with dread of situations from which escape might be difficult or help unavailable in the event of a panic attack or panic-like symptoms. Typical agoraphobia situations include shopping malls, waiting in lines, being at movie theaters, traveling by car or bus, being in crowded restaurants and stores, and being alone.
The most recent large-scale surveys of the adult population of the United States show that from 5 to 8% of individuals experience panic disorder and/or agoraphobia at some time in their lives. This means that somewhere between 15 and 25 million people in the United States alone suffer from panic disorder and/or agoraphobia. One out of every 12 people suffers from panic disorder and/or agoraphobia at some time in his or her life. In addition, many people have occasional panic attacks that do not develop into panic disorder. For example, over 30% of the population has had a panic attack during the past year, usually in response to a stressful situation, such as an examination or a car accident. Moreover, a significant number of people experience occasional panic attacks from "out of the blue" or for no real reason"estimates range from 3 to 14% in the last year.