Panic disorder is a common anxiety disorder and is often a chronic disabling condition (Bruce et al., 2005 and Kessler et al., 2006). Many studies have reported low health-related quality of life (HRQOL) and significant impairment in patients with panic disorder (Davidoff et al., 2012). In addition, Sherbourne et al. (1996) reported that panic patients had even lower HRQOL level than those of patients with other major chronic medical illnesses such as diabetes mellitus, heart disease, and chronic lung problems. Until recently, however, little attention has paid to the question of predictive factors of HRQOL in panic disorder. It is surprising and interesting that several researchers have repeatedly found a limited explanatory role of panic-related symptoms per se as a predictor of HRQOL in panic patients (Rapaport et al., 2005 and Carrera et al., 2006). Rapaport et al. (2005) reported that symptom severity (panic attacks) explained only 3.8% variance in QOL. Carrera et al. (2006) found that anxiety and depressive symptoms, age, frequency of panic attacks and agoraphobic avoidance accounted for 18–42% of the variance in QOL. Although the significant clinical correlates include panic severity, depressive symptomatology, neuroticism, and worry, research is sparse on the topic of psychological variables on HRQOL of panic patients other than illness-related symptomatology (Hollifield et al., 1997, Katerndahl and Realini, 1997 and Carrera et al., 2006). Besides illness-related symptomatology, individual factors such as individual cognitive and personality trait, genetic polymorphisms, numerous stressors may affect HRQOL (Kung et al., 2006, Pais-Ribeiro et al., 2007, Zou et al., 2010 and Margetic et al., 2011). In panic disorder, both anxiety sensitivity and trait anxiety are well known anxiety-related individual traits. They also have been widely used in research for panic disorders and many studies have revealed that both anxiety sensitivity and trait anxiety play important roles in symptom severity, psychopathology, course, and prognosis (Ehlers, 1995, Eke and McNally, 1996, Carrera et al., 2006, Roppongi et al., 2010, Park et al., 2012 and Tanaka et al., 2012). Although they both are closely associated with panic disorder, they differ in that anxiety sensitivity is defined as fear of anxiety-related sensations and considered to be a dispositional variable (Reiss and McNally, 1985) while trait anxiety refers to a general tendency to perceive situations as threatening (Spielberger et al., 1983). McNally (2002) provides a good explanation showing the differences between anxiety sensitivity and trait anxiety. People not only vary in their tendency to experience anxiety symptoms but also vary in their tendency to respond fearfully to them (i.e. fear of fear). The former is related to trait anxiety whereas the latter is anxiety sensitivity. They also differ in that anxiety sensitivity is closely related to panic attack and panic disorder whereas trait anxiety is related to general and nonspecific factors (Taylor et al., 1992). Furthermore, several studies showed that the anxiety sensitivity is a better predictor of response to biological challenges than trait anxiety (Rapee and Medoro, 1994, Eke and McNally, 1996 and Sturges et al., 1998). Thus, anxiety sensitivity as well as trait anxiety needs to be included in evaluating panic patients.
However, there are no data about the HRQOL in Korean panic patients as well as about the predictive roles of anxiety-related individual trait (i.e., anxiety sensitivity and trait anxiety) in assessing HRQOL in patients with panic disorder. Thus, in the present study, we hypothesized that Korean panic patients would show lowered HRQOL compared to healthy controls and that higher anxiety sensitivity or trait anxiety would predict lower HRQOL in panic patients.
