Psychophysiological correlates of anxious apprehension: Trait worry is associated with startle response to threat.

Worry is a form of repetitive negative thought that is closely associated with anxiety disorders. Worry has been described as anxious apprehension and conceptualized as reflecting heightened anticipation of potentially threatening future events. However, it is unclear whether people who tend to worry show heightened physiological reactivity when anticipating threat, especially if the threat is uncertain. In the current study, community participants (n = 52) completed a threat anticipation task featuring uncertain threat, certain threat, and safety while the startle response to auditory probes was measured. Self-reported tendency to worry was assessed using the Penn State Worry Questionnaire, and anxiety disorder status was assessed via a clinical interview. A repeated-measures general linear model showed a main effect of threat level on the startle response, as well as a significant three-way interaction among threat level, worry, and anxiety disorder status. Follow-up tests showed that higher worry was associated with blunted startle responses to threat but particularly to uncertain threat among participants with a history of anxiety disorders. Worry did not moderate startle responding in participants without a history of anxiety disorders. These results indicate that psychophysiological correlates of worry depend on clinical status and suggest that trait worry is associated with physiological blunting to threat in individuals with a history of anxiety disorders, particularly when threat is uncertain. Implications for theoretical models of worry are discussed.