P300 changes in major depressive disorders with and without psychotic features.

Background: Although there are many P300 studies in depressive patients, only a few studies have focused on the effects of psychotic features in depression and of response to antidepressant treatment on P300. This study was designed to investigate possible differences in the P300 component of event-related potentials in depressed patients with and without psychotic features and if any, to see whether these changes altered with treatment of depression.

Methods: Thirty-six patients with major depressive disorder diagnosed according to DSM-IV, and 20 healthy control subjects were involved in the study.