We aimed to examine whether anxiety sensitivity and agoraphobic fear could affect the time taken to remission after 24 weeks of open-label escitalopram treatment of patients with panic disorder (PD). We recruited 158 patients, and 101 patients completed the study. Clinical severity and psychological characteristics were assessed at baseline and 4, 12, and 24 weeks after the treatment, using the Clinical Global Impression-Severity (CGI-S), the Hamilton Rating Scales for Anxiety and Depression, the Anxiety Sensitivity Index-Revised (ASI-R), the Albany Panic and Phobia Questionnaire (APPQ), and the Panic Disorder Severity Scale (PDSS). Remission was defined as the absence of full panic attacks and PDSS scores of 7 or less. Completing patients were stratified according to the time taken to remit: early (n = 20) and late (n = 58) remission and non-remission groups (n = 23). There were no significant differences among the three groups at baseline on the CGI-S and the PDSS mean scores. However, early remitters had significantly lower scores than late remitters and non-remitters on the ASI-R and APPQ. In conclusion, anxiety sensitivity and agoraphobic fear can affect the time to remission after pharmacotherapy, and clinicians should consider the psychological characteristics of PD patients in order to achieve an optimal response to pharmacotherapy.
Panic disorder (PD) is a disabling condition characterized by recurrent unexpected panic attacks, persistent anticipatory anxiety about additional attacks, and worry about the implications of the attacks or significant related changes in behavior (Goodwin et al., 2005). The negative effects of PD on social, familial and occupational functioning are comparable to those of depression and even many chronic medical conditions (Kessler et al., 2006). Patients with PD face problems associated with impaired work performance, and the long duration of PD has negative impacts on subjective well-being, contact with friends, and self-realization (Cramer et al., 2005 and Waghorn et al., 2005). The longer PD persists, the greater the difficulty PD patients may experience in their social, familial and occupational functioning (Kessler et al., 2006 and Hendriks et al., 2011).
PD is known to be very responsive to pharmacotherapy in the acute phase, but the long-term response to pharmacotherapy seems to be variable. Even with medication, about a third of PD patients do not improve and one in five follows an unremitting and chronic course (Bruce et al., 2005, Heldt et al., 2006 and Marchesi et al., 2008). It is known that the sooner PD patients achieve a remission, the better their prognosis and future quality of life (Kampman et al., 2008).
Previous findings suggest some clinical factors associated with remission in PD patients. Pollack et al. (2002) found that early responders to anti-panic medications were more likely to be in remission at the end of treatment. In several studies, co-morbidity with depressive disorders, generalized anxiety disorder, or social phobia and severity of panic symptoms have been reported to result in a poorer prognosis (Keller et al., 1994 and Chavira et al., 2009). Other studies also suggest that agoraphobic fear and avoidance behavior predict an unfavorable outcome and a chronic course of PD (Scheibe and Albus, 1996 and Chavira et al., 2009). In previous long-term studies, PD patients without agoraphobia showed more improvement and a higher remission rate after pharmacotherapy when compared with those with agoraphobia (Carpiniello et al., 2002 and Bruce et al., 2005). Batelaan et al. (2010) recently suggested that the presence of agoraphobia predicts a higher proportion of time with PD, and that agoraphobic fear could be one of the most important predictors of treatment outcome in PD. Although a number of studies to investigated predictors of treatment response in PD, only a few variables such as severity of PD and agoraphobic fear and avoidance have been suggested to be relatively consistent predictors of treatment outcome (Slaap and den Boer, 2001 and Kampman et al., 2008).
Anxiety sensitivity (AS) is a dispositional cognitive construct that reflects an excessive fear of anxiety-related bodily sensations, and is caused by beliefs that these sensations are harmful and lead to physical, psychological, or social consequences (Reiss, 1991). According to AS theory, an individual with a high level of AS will experience amplified fear in response to stimuli that elicit anxiety and finds his/her own anxiety symptoms to be particularly aversive. Thus, AS is known to be one of the strong predictors of prognosis in anxiety disorders, such as generalized anxiety disorder, social phobia and especially PD (McNally, 2002, Plehn and Peterson, 2002, Struzik et al., 2004 and Schmidt et al., 2006). In addition, AS has been found to be useful for identifying individuals at risk for the emergence or relapse of panic attacks in some prospective longitudinal studies (Ehlers, 1995 and Schmidt et al., 2006). Previous studies have found that AS reduction is unlikely to occur after pharmacotherapy (Fava et al., 1994, McNally, 2002 and Simon et al., 2004), and that AS remains higher in PD patients after 3 months of drug treatment even though their severity of illness decreased after the treatment (Choi et al., 2004). These findings indicate that AS is a dispositional and cognitive variable, which could be related to treatment response.
The purpose of this study was to investigate whether the psychological characteristics of PD patients affect the time to remission after pharmacotherapy, and we examined the relationship between psychological characteristic and clinical remission after escitalopram treatment. We hypothesized that early remitters would have less severe panic symptoms and have lower AS and agoraphobic fear at baseline than late remitters or non-remitters.
