An analysis of startle responses in patients with panic disorder and social phobia

Abstract

Initial results from startle response studies indicate that Patients with anxiety disorders exhibit larger baseline startle responses than healthy controls (Butler et al., 1990; Morgan III, Grillon, Southwick, Davis, & Charney, 1995), have normal startle response habituation (Butler et al., 1990; Morgan III et al., 1995; Shalev, Orr, Peri, Schreiber, & Pitman, 1992), and more pronounced fear-potentiated startle during presentation of disorder-specific fear stimuli via slides or imagery (Hamm, Cuthbert, Globisch, & Vaitl, 1991; P. J. Lang, personal communication, August, 1995). The purpose of this study was to systematically replicate (see Sidman, 1960) and extend these findings by examining baseline startle responses, startle response habituation, prepulse inhibition, and fear-potentiated startle to physical threat-related, social threat-related, and non-threatening words in 12 patients with panic disorder, 22 patients with social phobia, and 15 healthy controls. Results indicated that patients with panic disorder exhibited significantly larger startle responses than healthy controls during baseline, pulse alone, prepulse inhibition and fear-potentiated trials. Although patients with social phobia consistently exhibited larger startle responses than healthy controls during all the trials a statistically significant difference was only found during the pulse alone trials. Implications and limitations of the study are discussed and it is suggested that future studies should examine the relationship between startle responses and all forms of anxiety disorders.