Clinical versus nonclinical panic: a test of suffocation false alarm theory.

Klein's suffocation false alarm theory of panic implies that suffocation sensations should distinguish clinical from nonclinical panic attacks better than should other symptoms. To test this theory, we conducted phenomenologic comparisons between attack patterns of patients with panic disorder and community subjects who had experienced unexpected panic. Effect size and multivariate analyses revealed that three cognitive symptoms best discriminated clinical from nonclinical panic (fears of dying, heart attack, and loss of control). These findings are consistent with cognitive theories of panic. Although lacking the discriminative power of cognitive symptoms, suffocation sensations had the largest effect size of any physiological symptom. Accordingly, suffocation sensations may be especially likely to give rise to the catastrophic thoughts that best discriminate clinical from nonclinical panic.