As listed in the DSM-IV-TR, the essential features of panic disorder are "the presence of recurrent, unexpected Panic Attacks, followed by at least 1 month of persistent concern ... or a significant behavioral change related to the attacks" (American Psychiatric Association, 2000). Panic disorder is characterized by instances of an intense sense of impending doom in which many patients will feel dizzy, hyperventilate and sweat. They can also experience chest pain, nausea and a fear of losing control. Because panic disorder can be accompanied by a high incidence of physical symptoms, it may be misdiagnosed or overlooked in assessments of a general medical condition by physicians or in emergency room care (APA, 2000; Hales et al., 1997). Panic disorder is chronic and may interrupt an individual's normal functioning. Each year, panic disorder will afflict more individuals than AIDS, stroke or epilepsy. Patients with panic disorder have a 20% incidence of suicide attempts, particularly when other psychiatric disorders are present.
Agoraphobia is a condition that can be diagnosed either with or without panic. According to the DSM-IV-TR, the patient fears being in places where escape would be difficult or embarrassing or where help might not be available. The situations are avoided or endured with marked distress or anxiety about having a panic attack or panic-like symptoms. For those suffering from panic disorder, agoraphobic avoidance may first occur in situations associated with the first panic attack (Faravelli et al., 1992).
Treatment of both panic disorder and panic disorder with agoraphobia will usually involve medication, cognitive-behavioral therapy (CBT) or a combination of the two. Medications used include selective serotonin reuptake inhibitors, tricyclic antidepressants, benzodiazepines and monoamine oxidase inhibitors (Saeed and Bruce, 1998). Cognitive-behavioral therapies may include relaxation, breathing retraining with or without the use of physiological monitoring, exposure therapy, and cognitive restructuring. It is generally understood that CBT is the most effective psychotherapeutic treatment modality for panic disorder and panic disorder with agoraphobia, and it can be used effectively in combination with pharmacologic therapy (Saeed and Bruce, 1998).
A large number of people who suffer panic attacks describe hyperventilation as one of their symptoms (Holt and Andrews, 1989). This observation lends support to the idea that hyperventilation may play a causal role in panic attacks. Panic attacks are seen as the product of stress-induced respiratory changes that then provoke fear of a heart attack or losing control of the ability to regulate bodily processes. Many researchers have found breathing retraining to be helpful (Ley, 1991). Clark et al. (1985) showed a marked reduction in panic attacks in patients who received two weekly sessions of breathing retraining and cognitive-restructuring training.
Interoceptive exposure involves having the patient perform such activities as purposefully overbreathing (hyperventilating) to experience the same symptoms they feel when experiencing a panic attack. This allows the patient to realize the control they have over their symptoms and to understand that the symptoms are not life-threatening. These exercises take place after the patient and therapist have established a trusting alliance and after cognitive restructuring, breathing retraining and relaxation techniques have been taught. This allows the patient to feel safe during the exposure and brings greater awareness of the cognitions attached to their physical responses of panic.
New technologies may prove invaluable to patients, especially those who do not respond to traditional exposure therapies. One study used a computer-aided system that administered anxiety questionnaires, self-exposure techniques and anxiety-management techniques to 15 patients with agoraphobia (Shaw et al., 1999). Most patients showed moderate-to-marked improvement, although they reported that they would have preferred some contact with a clinician.
Another study used a non-immersive, two-dimensional computer simulation to assess 18 patients with agoraphobia (Kirkby et al., 1999). Participants guided a computer figure into an elevator. Results showed improvement of agoraphobic symptomatology and a reduction in questionnaire scores following treatment. The data showed that participants guided the computer figure into the elevator more as exposure continued, an increase from 43% to 62% over the course of three treatment sessions. Questionnaire scores decreased over treatment, showing a lessening of anxiety.