Abnormalities of emotional processing have been reported in both anxiety and depressive disorders. Anxiety might be related to a hyperactive preattentive fear response or to a reduced efficiency of late regulatory processes, whereas depression might be related to a reduced response to positive emotions. In the present study event-related potentials (ERPs) were used to investigate involuntary processing of stimuli with different emotional valence in 33 healthy controls [HC] and 55 clinically stable patients (16 with panic disorder [PD], 15 with obsessive-compulsive disorder [OCD], 13 with unipolar depression [UD] and 11 with bipolar depression [BD]).

The ERPs were recorded during a target detection task, in which erotic, threatening, disgusting and neutral stimuli were used as distracters.

Patients showed abnormalities of the sequence, duration and topography of the ERP components related to emotional processing. Patients with anxiety disorders showed abnormalities of the early components in response to threatening stimuli. Patients with BD showed abnormalities of both early and late ERPs components. OCD and UD patients demonstrated similar abnormalities of the late ERP components in response to erotic stimuli.

According to our results, abnormalities of emotional processing are observed in both anxiety and affective disorders and might have both distinct and shared characteristics in these disorders.