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Panic disorder is a common, often chronic illness characterized
by recurrent, spontaneous panic attacks. These are short-lived episodes
of anxiety or intense fear and are accompanied by a range of somatic
symptoms, which may include tachycardia, tachypnea, dyspnea, chest
tightness, weakness, nausea, dizziness, and paresthesias. Panic
disorder may occur with or without agoraphobia, a condition typified
by avoidance of places or situations associated with anxiety. Panic
disorder with agoraphobia may be severely disabling, and patients
may be incapable of functioning socially or occupationally.
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Because many of the symptoms of panic disorder overlap with those
of acute medical illness, the initial point of contact for patients
with panic disorder is often the ED.
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When compared with patients with other psychiatric or medical
problems, patients with panic disorder have the highest rates of
use of ED services.1 Increased use can precede
the diagnosis of panic disorder by up to 10 years.2 Although
progress has been made in diagnosis and treatment, up to half of
those who have the disorder remain undiagnosed.
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Panic disorder is relatively common, with national lifetime and
12-month prevalences of 3.5% and 2.5%,3 respectively,
and a cross-national lifetime prevalence of 1.6% to 2.2%.4 The
age of onset is typically from late adolescence to the mid-30s.
The incidence may have a bimodal distribution, with the first peak
in late adolescence, followed by a second, smaller peak in the mid-30s.5
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Women are two to three times more likely than men
to develop panic disorder. There is some evidence that panic attacks
may remit during pregnancy, only to be exacerbated in the postpartum
period.6 Cultural factors may play a role in the
presentation of panic disorder. Sleep paralysis is a common symptom
of panic disorder in the black population,7 and
orthostatic-induced dizziness is a common trigger for panic attacks in
Vietnamese refugees.8 Ataque de nervios is
an anxiety syndrome in Hispanic cultures that, at times, has a similar
presentation to panic disorder.9
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The etiology basis of panic disorder is unknown. It is most likely
multifactorial in origin, with genetic, behavioral, and biologic
underpinnings.10
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First-degree relatives of patients with panic disorder have a
four- to sevenfold increased risk of developing the disorder, and
monozygotic twins have a higher concordance than dizygotic twins
for panic disorder.6,11
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Theorists in cognitive behavioral therapy (CBT) have proposed
that panic disorder is a response to internal cues. Heightened sensitivity
of body functions and/or cognitive misinterpretation of
these cues are postulated to trigger a conditioned fear response.
For example, a person with panic disorder can be more aware than
others that his or her heart rate has increased. He or she then
may misinterpret this cue as “I’m having a heart attack” and
become fearful. CBT theorists also hypothesize that anticipatory
anxiety ...