Panic Disorder 287
Descriptive Characteristics
Epidemiological studies indicate that panic disorder with or without agoraphobia have
1-year prevalence rates ranging from 1.1 to 2.7% and lifetime prevalence rates of 2.0–
4.7% (Eaton et al., 1991; Kessler et al., 1994; Kessler, Berglund, et al., 2005; Kessler,
Chiu, et al., 2005; Offord et al., 1996). This makes panic disorder second only to OCD
as the least common of the anxiety disorders discussed in this volume. As expected,
prevalence of panic disorder is much higher in primary care settings than in the general
population (Katon et al., 1986; Olfson et al., 2000). Moreover, there do not appear to be
significant ethnic differences in the prevalence of panic disorder (e.g., Horwath, John-
son, & Hornig, 1993; Kessler et al., 1994), although cultural factors do influence which
panic symptoms are more commonly reported and how they are labeled (see discussion
by Barlow, 2002; Taylor, 2000).
Panic attacks as well as panic disorder with or without agoraphobia are approxi-
mately twice as common in women as in men (Eaton et al., 1994; Gater et al., 1998;
Kessler et al., 1994). Moreover, agoraphobia may be particularly gendered, with women
representing approximately 75% of the agoraphobic population (Bourdon et al., 1988;
Yonkers et al., 1998). Panic disorder appears to take a more severe course in women
as indicated by more severe agoraphobic avoidance, more catastrophic thoughts, more
threatening interpretations of bodily sensations, and higher recurrence of panic symp-
toms (Turgeon, Marchand, & Dupuis, 1998; Yonkers et al., 1998). Women in general
may show a heightened tendency to report more physical symptoms, fear, and panic in
response to acute distress (Kelly, Forsyth, & Karekla, 2006). Furthermore, it is pos-
sible that increased panic disorder and agoraphobic avoidance in women is linked to a
higher rate of childhood physical and sexual abuse which could lead to increased hyper-
vigilance and overpredictions of threat (Stein, Walker, et al., 1996). Craske (2003),
however, notes that the main difference between men and women is in their reliance on
avoidance rather than in the number of reported panic attacks, which could be due to
socialization into the traditional feminine gender role.
Panic disorder usually begins in young adulthood with the ECA reporting a mean
onset age of 24 years (Burke, Burke, Regier, & Rae, 1990) and 75% of panic disorder
cases having first onset by age 40 in the NCS-R survey (Kessler, Berglund, et al., 2005).
Despite a relatively early onset, there is usually considerable delay between onset and
first treatment contact. In the NCS-R a median duration of 10 years occurred between
onset of panic disorder and first treatment contact (Wang, Berglund, et al., 2005).
Despite lengthy delays in seeking treatment, the vast majority of individuals with panic
disorder eventually do make treatment contact (Wang, Berglund, et al., 2005).
Like other anxiety disorders, onset of panic is often associated with stressful life
events such as separation, loss or illness of significant other, being a victim of an assault,
financial problems, work difficulties, personal health problems, unemployment, and the
like (e.g., Faravelli & Pallanti, 1989; Franklin & Andrews, 1989; Pollard, Pollard, &
Corn, 1989). In other studies a high incidence of past childhood sexual and physical
abuse has been found in panic disorder and agoraphobia, especially among women
(Pribor & Dinwiddie, 1992; Saunders, Villeponteaux, Lipovsky, Kilpatrick, & Veronen,
1992; Stein et al., 1996), although it is still uncertain whether rates of adverse early
childhood events are any higher in panic disorder compared to major depression or even
schizophrenia (Friedman et al., 2002). In an analysis of the NCS data set women with
panic disorder without comorbid PTSD were six times more at risk of having child-