PULMONARY-FUNCTION AND DYSPNEA SUFFOCATION THEORY OF PANIC/

This article presents a brief discussion of pulmonary function and pan ic attacks in the context of respiratory psychophysiology. Ley's (Beha viour Research and Therapy, 27, 549-554, 1989) earlier dyspnea/suffoca tion theory of panic is contrasted with Klein's (Archives of General P sychiatry, 50, 306-316, 1993) later false suffocation alarm theory. Th e distinction between ''dyspnea'' (the sensation of difficulty in brea thing) and ''suffocation'' (a condition that sometimes gives rise to d yspnea) is emphasized. The brief discussion is followed by a critical comparison of two recent studies on pulmonary function and panic. Asmu ndson and Stein (Journal of Anxiety Disorders, 8, 63-69, 1994) reporte d an association between forced expiratory flow rate (a measure of pul monary function) in panic disorder patients and the severity of panic- related symptoms, They interpreted their findings as support for the d yspnea/suffocation theory of panic since severity of dyspnea is a cons equence of pulmonary function. Spinhoven et al. (Behaviour Research an d Therapy, 33, 457-460, 1995) failed to replicate the findings of Asmu ndson and Stein. The present paper provides a critical analysis of the study by Spinhoven et al. and concludes that the failed attempt to re plicate may have been a consequence of a flawed methodology (the subje cts of the two studies are not comparable on a crucial pulmonary test) and a statistical anomaly (disproportionately small differences betwe en means that exceed predictions based on sampling error). A recommend ation is made that future attempts to replicate should pay special car e to avoid the possibility of experimenter-demand effects. (C) 1998 El sevier Science Ltd. All rights reserved.