Aversive responding to safety signals in panic disorder: the moderating role of intolerance of uncertainty.

An inability to inhibit aversive responding during conditions that signal safety may be a core dysfunction associated with anxiety disorders. However, there has been inconsistent evidence as to whether individuals with panic disorder (PD) exhibit aversive responding during safety signals. It is therefore possible that only certain subgroups of PD patients, particularly those with high levels of intolerance of uncertainty (IU), evidence this type of abnormal responding. The aim of the current study was to examine whether IU moderates the association between PD and startle potentiation during (a) safety and (b) threat periods during a threat-of-shock task. Participants included 172 adults, 74 of which had current diagnoses of PD. Results indicated that at high levels of IU, PD was associated with greater startle potentiation during safety. At low levels of IU, PD was not associated with startle potentiation during safety. IU did not moderate the effect of PD on threat responding. These results suggest that PD patients with high levels of IU fail to inhibit aversive responding during safety, possibly due to a tendency to interpret distal threat as distressing.