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.
From the *Department of Psychiatry, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin; †Dahlem Institute of Neuroimaging of Emotion (DINE), Cluster of Excellence "Languages of Emotion," Freie Universität Berlin, Berlin; ‡Department of Psychiatry and Psychotherapy, University Hospital, Bonn, Germany; §Department of Psychiatry, University Hospital, Bern, Switzerland; Departments of ∥Psychiatry, and ¶Mental Health, The Johns Hopkins University, Baltimore, MD; #Jonathan Swift Clinic, St James Hospital, Dublin, Ireland; **University Hospital Umea, Umea, Sweden; ††Department of Neuropsychiatry and Neurology, National Hospital for Neurology and Neurosurgery, London, United Kingdom; ‡‡Evangelisches Krankenhaus Bielefeld, Bielefeld; §§Department of Psychiatry and Psychotherapy, Ludwig-Maximilian University, Munich, Germany; ∥∥University Hospital Gent, Gent, Belgium; and ¶¶Centre for Neuroscience, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom.
Received May 18, 2009; accepted after revision February 23, 2010.
Reprints: Malek Bajbouj, MD, Department of Psychiatry, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Eschenallee 3, 14050 Berlin, Germany (e-mail: email@example.com).
Malek Bajbouj and Angela Merkl contributed equally to this study.
Declaration of interest: Cyberonics Inc (Houston, Tex), manufacturer of the vagus nerve stimulation therapy device, provided partial funding for the conduct of the D03 study. This article describes a secondary analysis of data from that trial. Under the complete direction of the authors, Cyberonics Inc provided assistance with obtaining the analysis and formatting the manuscript.