Startle response and anxiety sensitivity: subcortical indices of physiologic arousal and fear responding

There is a well-established and clinically meaningful relation between the cognitive-affective-based construct of anxiety sensitivity (AS) and risk for the development and maintenance of anxiety psychopathology (B. J. Cox, Fuentes, Borger, & Taylor, 2001). Research findings within this area have revealed mixed results; however, there is evidence to suggest that some individuals with anxiety disorder diagnoses may demonstrate enhanced subcortical arousal (e.g., exaggerated startle response to unexpected, aversive stimuli [A. M. Waters et al., 2008], and deficient prepulse inhibition [PPI; S. Ludewig, Ludewig, Geyer, Hell, & Vollenweider, 2002]), it is presently unclear whether these differences are found within the general population. To address this gap in the extant literature, the current investigation examined the impact of AS on acoustic startle response magnitude and PPI. Results indicated that individuals high and low in AS differ with regard to subcortical measures of arousal, with individuals expressing high levels of AS demonstrating enhanced startle response and deficient PPI. Results are discussed in terms of the role of the cognitive-affective-based factor of AS in the context of physiologic markers for vulnerability for anxiety psychopathology.