Perceptual asymmetry differences between major depression with or without a comorbid anxiety disorder: a dichotic listening study.

Predictions that anxious and nonanxious depression would differ in perceptual asymmetry (PA), as well as in sensitivity for perceiving emotional words, were evaluated using dichotic listening tasks. A total of 149 patients having a major depressive disorder (51 with and 98 without an anxiety disorder) and 57 healthy controls were tested on fused-word and complex tone tasks. The anxious and nonanxious depression groups showed a consistent difference in PA across tasks; that is, the anxious group had a larger left-ear advantage for tones and a smaller right-ear advantage for words when compared with the nonanxious group. There was no group difference in sensitivity for perceiving emotional words. Patients having an anxious depression appear to have a greater propensity to activate right than left-hemisphere regions during auditory tasks, whereas those having a nonanxious depression have the opposite hemispheric asymmetry.