A PRELIMINARY-ANALYSIS OF PULMONARY-FUNCTION IN PANIC DISORDER - IMPLICATIONS FOR THE DYSPNEA-FEAR THEORY

The present study investigated the relationship between pulmonary function and panic symptomatology in 15 panic disordered (PD) patients. Patients were divided into two groups based on high and low FEF 50% scores, a relatively effort-independent measure of pulmonary function that has been used as an early indicator of obstructive lung disease, using a median-split procedure. Overall, the PD patients did not exhibit any significant impairments in pulmonary function. However, low FEF 50% patients had significantly lower FEV1/FVC ratios compared to the high FEF 50% patients. Low FEF 50% PD patients also reported experiencing a greater severity of panic-related respiratory symptoms and cognitive/fear symptoms during episodes of panic. They did not, however, differ from high FEF 50% patients in terms of fear of general anxiety symptoms, state anxiety, past-week respiratory difficulty, or past-week panic episodes. These results suggest that the subgroup of PD patients with lower FEF 50% scores are the subgroup most likely to experience respiratory and cognitive/fear symptoms during panic attacks. Further, it seems plausible that the low FEF 50% scores, low FEV1/FVC ratio, and associated respiratory symptoms may be representative of the early signs of chronic pulmonary obstruction in these patients. Implications to the dyspnea-fear theory and treatment issues are discussed.