Emotion recognition in chronic treatment-resistant depression : before and after neurosurgical treatment

Abstract

The neuroanatomical structures underlying Major Depressive Disorder (MDD) are not fully understood. Invasive treatment options now exist that target the brain structures associated with MDD. In part one of this study, the effects of MDD on emotion processing are being measured and discussed. Emotion processing was examined in patients with chronic, treatment resistant depression (n = 15) and a healthy control group (n = 38). Emotion processing abilities were impaired in the MDD group, especially those of disgust recognition. In part two, seven of the fifteen MDD patients that had received an Anterior Cingulotomy (ACING) and eight of the fifteen MDD patients that had received a Vagus Nerve Stimulation (VNS) as an intervention for chronic, treatment resistant depression were presented with the same series of emotional processing tasks given in part one. Their post surgical performance was compared with their pre surgical performance. After surgery, the ACING group showed decreased emotion processing abilities and the VNS group showed improvements. Findings suggest that emotional functions assumed to be associated with certain neural structures that are adversely affected in patients with MDD may be responsible for some of the clinical features of MDD.