Deficient information processing and dysfunctional cognitions in unmedicated panic disorder patients

Objectives: Plasticy of the startle reflex such as startle reactivity, prepulse inhibition (PPI) and habituation are operational measures of information processing that is abnormal in several neuropsychiatric disorders that are characterized by deficits in supression or inhibition of intrusive or irrelevant stimuli. Method: Acoustic startle reactivity, habituation, and PPI were assessed in unmedicated patients with panic disorder (m/f=7,7) and age- and gender-matched healthy controls (m/f=14,14). Results: Panic disorder patients exhibited increased startle reactivity, reduced habituation, and significantly reduced PPI. Furthermore, in PD patients, decreased habituation correlated significant with higher cognitive dysfunctions but not with PPI. Discussion: These observed deficits in PPI and habituation could reflect a more generalized difficulty in suppressing or gating information in panic disorder. The correlation between dysfunctional cognitions and deficient habituation supports the hypothesis that subjects with PD have abnormalities in the early stages of information processing, which led to a cascade of downstream effects on cognition.