ABSTRACT
Patients with panic disorder suffer overwhelming anxiety and physical symptoms experienced as if they were coming `from out of the blue' (American Psychiatric Association, 2000). Panic disorder has a 3.7 percent prevalence rate in the US population and can exist with or without agoraphobia (Kessler et al., 2006). Pharmacotherapy is a ®rst line treatment for panic disorder (American Psychiatric Association, 2007). However, patients often relapse when tapered off medication (Wiborg and Dahl, 1996; Mavissakalian and Michelson, 1986; Mavissakalian and Perel, 1999), and many patients with panic disorder do not tolerate the side effects of psychotropic medications or refuse to take them (Barlow et al., 2000; Hoffmann et al., 1998; Marks et al., 1993). Cognitive behavioral therapy (CBT) is another ®rst line treatment, as it is the psychotherapy with the best-documented ef®cacy (American Psychiatric Association, 2007; Barlow et al., 2000; Kenardy et al., 2003; Ost et al., 2004). Despite these ®ndings, CBT is not helpful for all patients and non-response, incomplete response, and relapse rates remain worrisome (Barlow et al., 2000; Craske et al., 1991; Marks et al., 1993; Shear et al., 1994). A better understanding of patients who do not respond to the better-studied empirically supported treatments is important, as panic disorder is associated with high rates of utilization of medical services, poor functioning on a range of psychosocial indices, and elevated rates of suicide (Holli®eld et al., 1997; Markowitz et al., 1989).
