In subjects with panic disorder (PD), previous studies have reported a high prevalence of alexithymia, a poor inhibition of emotional interferent stimuli on the Emotional Stroop test, and a recognition bias toward fear for facially expressed emotions. Other studies, however, have reported no difference between PD patients and healthy subjects (HS) for emotional stimuli processing.

Twenty-eight drug-free patients with PD and 32 HS were included in the study. The two groups did not differ for age, sex, education level and handedness. The Toronto Alexithymia Scale-20 items (TAS-20) was used to evaluate alexithymia. The Emotional Stroop test was administered to evaluate the ability to suppress interference from different emotional valence stimuli. The Bouhuys' test was used to evaluate the perception of facially expressed emotions.

Compared to HS, patients with PD showed: 1) higher frequency of alexithymia and borderline alexithymia, in particular higher scores on the first (difficulty in identifying feelings) and the second (difficulty in describing feelings) dimension of alexithymia; 2) higher mean reaction time on the Emotional Stroop test for panic-related stimuli; 3) no difference on the Bouhuys' test.

Our data suggest that, in patients with PD, a reduced awareness of emotional experiences, which characterize alexythimic subjects, may underly anxiety symptoms and panic attacks, leading to a failure to identify emotional reactions with a preferential activation of alarm and defence behaviours.