Psychophysiology, 38:S30, 2001.

ERPs during tonal and phonetic oddball tasks in patients having depressive and anxiety disorders

Gerard Bruder, JÃ¼rgen Kayser, Craig Tenke, Paul Leite, Jonathan Stewart, Frederic Quitkin

Department of Biopsychology, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032-2695, USA

Abstract

Differences have been reported between depressed patients with versus without an anxiety disorder in EEG alpha asymmetry and dichotic listening. The present study assessed the effects of having a depressive disorder, an anxiety disorder, or comorbidity of both disorders on ERPs recorded from 30 sites during oddball tasks using binaurally presented complex tones or syllables. ERPs of four groups were compared: (1) patients having a "pure" depressive disorder (n=58); (2) patients having an anxiety disorder alone (n=22); patients having comorbidity of these disorders (n=18); and (4) healthy controls (n=49). A principal components analysis with unscaled Varimax rotation derived five previously identified components: N1 (N100), N2 (N215), early P3 (P315), late P3 (P400) and a late positive slow wave. Early P3 was significantly smaller in depressed patients compared to non-depressed subjects. However, patients having comorbidity of depressive and anxiety disorders had a larger late P3 than the other groups. Task-dependent hemispheric asymmetries for N2 and P3 potentials replicated our prior findings (Kayser et al., 1998), i.e. larger ERP components of the N2-P3 complex over right frontocentral regions for tones and over left temporoparietal regions for syllables. There were no differences in these task-dependent asymmetries among groups. To the extent that N2 and P3 asymmetries in the tonal and phonetic oddball tasks reflect differential involvement in pitch (right frontotemporal) and phoneme (left temporoparietal) discrimination, these do not appear to differ in depressed patients, with or without an anxiety disorder, and healthy controls.

Keywords: ERP, Depression, Anxiety