Significance: Electroconvulsive therapy is controversial: How does a major electrical discharge over half the brain result in recovery in disorders such as refractory major depression and manic depression, which are apparently different diseases? We find local but not general brain anatomy changes following electroconvulsive therapy that are differently distributed in each disease, and the areas affected are those implicated as abnormal in each disorder. An interaction between electroconvulsive therapy and specific pathology appears to be responsible for the therapeutic effect. Our results have implications for other electrically based brain treatments, such as deep brain stimulation and transcranial magnetic stimulation.

One of the major goals of antidepressant treatment is a sustained response and remission of depressive symptoms. Some of the previous studies of vagus nerve stimulation (VNS) have suggested antidepressant effects. Our naturalistic study assessed the efficacy and the safety of VNS in 74 European patients with therapy-resistant major depressive disorder. Psychometric measures were obtained after 3, 12, and 24 months of VNS. Mixed-model repeated-measures analysis of variance revealed a significant reduction (P ≤ 0.05) at all the 3 time points in the 28-item Hamilton Rating Scale for Depression (HRSD28) score, the primary outcome measure. After 2 years, 53.1% (26/49) of the patients fulfilled the response criteria (≥50% reduction in the HRSD28 scores from baseline) and 38.9% (19/49) fulfilled the remission criteria (HRSD28 scores ≤ 10). The proportion of patients who fulfilled the remission criteria remained constant as the duration of VNS treatment increased. Voice alteration, cough, and pain were the most frequently reported adverse effects. Two patients committed suicide during the study; no other deaths were reported. No statistically significant differences were seen in the number of concomitant antidepressant medications. The results of this 2-year open-label trial suggest a clinical response and a comparatively benign adverse effect profile among patients with treatment-resistant depression.