Panic disorder is one of the most widely recognized, publicized, and investigated anxiety disorders. Individuals diagnosed with panic disorder experience discrete, recurrent, unexpected episodes of fear or discomfort that develop abruptly and reach a peak within 10 min. These episodes of fear are accompanied by four or more symptoms such as racing heart, chest pain, shortness of breath, dizziness, sweating, numbness, chills, shaking, fear of dying, fear of losing control, and/or fear of going crazy. Individuals with panic disorder experience persistent concern about experiencing future panic attacks, and worry about the consequences of the panic attacks and/or a change in behavior because of them (e.g., reducing time spent at work or cutting back on social activities). As with the other anxiety disorders, these symptoms cannot be directly caused by a substance, such as caffeine, or by a general medical condition, such as an overactive thyroid.
Panic Disorder with Agoraphobia
Panic disorder may occur with or without agoraphobia. Individuals with panic disorder with agoraphobia (PDA) avoid situations that might be difficult to leave or escape from, or avoid situations in which help would be unavailable should a panic attack occur. For individuals with PDA, situations that are commonly avoided include being in grocery stores, shopping malls, restaurants, movie theaters, and churches or temples, driving far from home, traveling over bridges, being in crowds, and using public transportation. Agoraphobic avoidance typically develops as a coping strategy for trying to avoid having another panic attack. Individuals with PDA avoid going places or being in situations where panic attacks may occur or have occurred in the past. It seems that secondary gain in the form of negative reinforcement (anxiety diminishing when the person leaves a situation) and/or positive reinforcement (extra attention or help from other people) may also contribute to the development of agoraphobia. Agoraphobic avoidance may interfere mildly (e.g., grocery shopping during a time of day when lines are minimal) or severely, to the point that an individual may be entirely housebound or only venture outside with a specific “safe” person.
Individuals with PDA may also try to avoid physical symptoms that resemble panic attacks. They may avoid physical activities such as exercise (which may cause racing heart or chest tightness), being in hot, stuffy rooms (which may cause sweating or shortness of breath), or alcohol (which may cause dizziness). White and Barlow refer to this cluster of responses as “interoceptive avoidance,” and hold that it is just as important as the situational avoidance just described.
Epidemiologic studies worldwide indicate that between 1.5% and 3.5% of people have panic disorder at some point during their lifetime. Between 1% and 2% of the population is affected with panic disorder during any 1-year period. Additionally, about 33%-50% of individuals with panic disorder also have agoraphobia. Panic disorder is typically a disorder of adults, beginning at a median age of 24 years. The average age for seeking treatment is 34 years. Twice as many women experience panic disorder as men, and increasing severity of agoraphobia is associated with a higher proportion of women. The most common explanation for this marked difference in rate of occurrence among men and women involves cultural factors, in that it is generally more acceptable for women to report fear and to avoid various situations due to fear.
PDA tends to be chronic and result in high levels of occupational, social, and physical disability according to several important studies that followed individuals over time. Antony and colleagues found that people with panic disorder reported more impairment than people with chronic medical conditions such as end-state renal disease or multiple sclerosis.
Etiology of Panic Disorder
Most individuals with panic disorder (more than 70%) can clearly remember a stressful situation (e.g., either interpersonal difficulties, concern about their physical well being, or having a frightening experience with drugs such as anesthetics or marijuana) that was going on when their panic attacks began. Barlows model of the etiology of panic disorder posits a nonspecific biological predisposition to react to negative events with emotionality, anxiety, and possibly panic attacks. This biological predisposition, combined with a psychological predisposition to focus anxiety on somatic events that are perceived to be uncontrollable and potentially threatening or dangerous, creates a diathesis. This focus on somatic events or life stress then triggers an unexpected panic attack. Among those with the specific biological and psychological vulnerabilities (the diathesis), anxiety becomes focused on experiencing future panic attacks and worry about the consequences of the attacks, and panic disorder subsequently develops.
Frequent Health Care Seeking
Because panic attack symptoms mimic a variety of cardiac, respiratory, neurological, and gastrointestinal symptoms, a key component of a diagnostic assessment of panic disorder includes ruling out potential medical causes for the panic symptoms through a medical evaluation. Most patients with panic disorder (80%-89%) initially seek treatment in general medical and not mental health settings. This is somewhat problematic, given that panic disorder is not typically recognized in medical settings. Seventy percent of patients with panic disorder see an average of 10 physicians before being correctly diagnosed. Of patients with panic disorder, 61%-80% are not recognized as having panic disorder in the primary care setting and 98% are not correctly identified in emergency departments. When compared to people with other psychological disorders (such as depression), those with panic disorder use medical services far more frequently, and are among the highest utilizers of medical services, especially emergency departments.
Why is panic disorder so rarely diagnosed in medical settings? Roy-Byrne and Katon suggest that patient barriers (e.g., the stigma of mental illness, lack of knowledge of the mind-body connection), physician barriers (e.g., the tendency to look for physical causes of somatic symptoms, overemphasis on not missing a medical disorder due to our litigious society), and system and process of medical care barriers (e.g., lack of adequate time for primary care physician diagnosis, an overwhelmed medical system) all contribute to the problem of panic disorder not being recognized.
In primary care settings, physicians may rule out an organic etiology for a patients physical symptoms, but offer no additional treatment or explanation beyond the feedback that there is nothing physically wrong with him or her. Although the medical community may assume that informing patients they do not have a medical problem is reassuring, for patients with panic disorder this can be frustrating because they still do not have an explanation for their intense and frightening physical symptoms.
Panic Disorder Treatment
Psychological Approaches
Recent studies have suggested that in general, patients with anxiety disorders are seldom treated, and those who are treated often receive ineffective treatments. The psychological treatment for panic disorder that has received indisputable empirical support is cognitive-behavioral therapy (CBT). More than 25 independently conducted, controlled clinical trials have demonstrated the effectiveness of CBT. Craske and Barlow recently summarized statistics from all randomized controlled trials and concluded that 76% of treatment completers are free of panic at the end of treatment, and 78% are still panic free 2 years later. Importantly, 66% of patients maintained or improved on the gains made in treatment even after treatment ended. In addition to eliminating panic attacks, researchers found that CBT improves quality of life.
The CBT approach to treating panic disorder is based on cognitive and learning theory principles of fear acquisition and reduction. The goal is to reduce patients’ fear and avoidance of internal and external cues associated with panic attacks. CBT is directed at correcting patients’ maladaptive thoughts and behaviors that initiate, sustain, or exacerbate panic symptoms. CBT targets fears of bodily sensations as well as anxious apprehension over the recurrence of panic. CBT is typically conducted in a structured, short-term modality of 10-15 sessions, and may be done in an individual or group format.
There are several key components of CBT for panic disorder. These include use of daily monitoring forms and homework, psychoeducation to correct misappraisals of bodily sensations, cognitive restructuring to challenge fearful thoughts regarding the meaning of bodily sensations, diaphragmatic breathing retraining to achieve somatic control, interoceptive exposure to reduce the fear of bodily sensations, and (if indicated) in vivo exposure to reduce the fear of agoraphobic situations. Some experts argue that the interoceptive exposure component of treatment is the most important. Interoceptive exposure involves deliberately provoking feared physical sensations like breathlessness, dizziness, and accelerated heart rate by means of exercises such as forced hyperventilation, spinning, and running in place, with the goal of reducing the fear of bodily sensations through habituation.
Additionally, the CBT approach to treating panic disorder discourages avoidance of activities that may produce physical sensations (e.g., ingesting caffeine, exercise, hot conditions). Moreover, any activity that is done to keep the person’s mind off feelings of anxiety (distraction) is also discouraged. This includes counting, reading coping statements, playing loud music, drinking water, and so on. These activities are discouraged because they are not helpful in the long run and do not alter the underlying processes that lead to panic attacks, and thus prevent corrective learning from occurring. More recently, the argument has been made that diaphragmatic breathing is a form of distraction, and therefore should not be taught as a coping skill. For individuals with agoraphobic avoidance, situational in vivo exposure treatment typically begins by creating a hierarchy of feared situations or activities that have been regularly avoided such as grocery stores, driving, malls, crowds, and so on. Patients are then encouraged to repeatedly enter and remain in these feared situations, utilizing therapeutic coping skills until their anxiety diminishes.
Pharmacologic Approaches
In general, pharmacotherapy for panic disorder is concerned primarily with the elimination of panic and limited symptom attacks, with the expectation that when those are controlled, reductions in anticipatory anxiety and agoraphobic avoidance will follow. The three major classes of medications used to treat panic disorder are benzodiazepines, tricyclic antidepressants (TCAs), and selective serotonin reuptake inhibitors (SSRIs).
The efficacy of benzodiazepines, such as alprazolam (Xanax), diazepam (Valium), clonazepam (Klonopin), and lo-razepam (Ativan), in the acute treatment of panic disorder has been demonstrated in several trials. In most studies, 50%-75% of patients were panic free by the end of treatment. With aggressive treatment, panic attacks can be reduced within a few days, and global improvement commonly appears within a few weeks. Unfortunately, approximately 50% of patients relapse when the drug is discontinued. There is some risk of drug tolerance, abuse, and dependence, although this appears to be a problem principally among individuals with a personal or family history of drug abuse or dependence. Nonetheless, physiological dependence develops in most patients with prolonged benzodiazepine use, as indicated by the appearance of withdrawal symptoms during drug discontinuation.
Since the 1960s, over 15 controlled clinical trials have demonstrated the efficacy of tricyclic antidepressants with panic disorder, and have demonstrated both short-term and long-term effectiveness. Imipramine (Tofranil), and less studied clomipramine (Anafranil), desipramine (Norpramin), and nortriptyline (Pamelor), are thought to selectively suppress uncued panic attacks. Despite their empirical effectiveness, clinically, the TCAs are often accompanied by troublesome side effects that are difficult to tolerate, such as weight gain, constipation, and blurred vision. The termination of TCA use is also linked with high relapse rates.
The selective (SSRIs) are considered by many to be the state-of-the-art treatment for panic disorder. Numerous studies have demonstrated the efficacy of SSRIs including paroxetine (Paxil), fluoxetine (Prozac), and sertraline (Zoloft). SSRIs are often preferred to other medications because they are considered to be safer, have fewer side effects, and are easier to dose than the TCAs, and lack the abuse and dependence potentials of the benzodiazepines. Additionally, the SSRIs are also effective in the treatment of depression and other comorbid disorders.
In many clinical settings as well as research studies, patients with panic disorder receive combined (psychological and pharmacological) treatment for panic disorder. In the largest combined treatment study to date, by Barlow and colleagues, five treatment groups were compared: CBT alone, imipramine alone, placebo, CBT plus imipramine, and CBT plus placebo. The authors concluded that although both CBT alone and imipramine alone are clearly effective, there does not seem to be an advantage to combining the treatments. However, after treatment was stopped, CBT had better effects in follow-up, whereas people on medication typically lost the gains they made after they stopped treatment.
Although CBT is an effective psychological treatment for panic disorder, disseminating effective psychological treatments to those who need them remains one of the major obstacles facing mental health practitioners. There has been a trend toward making treatments briefer, more intense, and more self-directed. There is wide agreement that primary care settings will become an increasingly important arena for the delivery of behavioral health care in general. Because so many patients with panic disorder present for treatment initially in medical settings, including primary care and emergency departments, innovative treatments that are adapted to be suitable in these settings are important. Studies of treating panic attack patients in the emergency department with exposure-based principles have been effective. Additionally, treatments for noncardiac chest pain using cognitive-behavioral techniques delivered in emergency department and cardiology settings have also showed promise. Because we have effective psychological and pharmacologic treatments for panic disorder, efforts focused on improving recognition and treatment of panic disorder patients in medical settings has recently attracted much attention and is becoming an important focus for future research and changes in clinical practice settings.
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