Resting EEG measures of brain arousal in a multisite study of major depression
Christine Ulkea,g, Craig E. Tenkeb, Jürgen Kayserb, Christian Sandera,g, Daniel Böttgera,g, Lidia YX Wongb, Jorge E Alvarengab, Maurizio Favac, Patrick J. McGrathb, Patricia J. Deldind, Melvin G. Mcinnisd, Madhukar H. Trivedie, Myrna M. Weissmanb, Diego A. Pizzagallif, Ulrich Hegerla,g, Gerard E. Bruderb
aDepartment of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany; aDepartment of Psychiatry, Columbia University College of Physicians & Surgeons and New York State Psychiatric Institute, New York, NY, USA; cDepression Clinical and Research Program, Massachusetts General Hospital, Boston, Massachusetts, USA; ddDepartments of Psychology and Psychiatry, University of Michigan Health System, Ann Arbor, Michigan, USA; eDepartment of Psychiatry, UT Southwestern Medical Center, Dallas, Texas, USA; fDepartment of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, Massachusetts, USA; gResearch Centre of the German Depression Foundation, Leipzig, Germany
Received 12 May 2018; revised 17 July 2018; accepted 18 July 2018; published online 5 September, 2018.
Abstract
Several studies have found upregulated brain arousal during 15-min EEG recordings at rest in depressed patients. However, studies based on shorter EEG recording intervals are lacking. Here we aimed to compare measures of brain arousal obtained from 2-min EEGs at rest under eyes-closed conditions in depressed patients and healthy controls in a multisite project  Establishing Moderators and Biosignatures of Antidepressant Response for Clinical Care (EMBARC). We expected that depressed patients would show stable and elevated brain arousal relative to controls. Eighty-seven depressed patients and 36 healthy controls from four research sites in the United States were included in the analyses. The Vigilance Algorithm Leipzig (VIGALL) was used for the fully automatic classification of EEG-vigilance stages (indicating arousal states) of 1-sec EEG-segments; VIGALL-derived measures of brain arousal were calculated. We found that depressed patients scored higher on arousal stability (Z = -2.163, p = .015) and A-Stages (dominant alpha activity; p = .027) but lower on B1-Stages (low voltage non-alpha activity, p = .008) compared to healthy controls. No significant group differences were observed in Stage B2/3. In summary, we were able to demonstrate stable and elevated brain arousal during brief 2- min recordings at rest in depressed patients. Results set the stage for examining the value of these measures for predicting clinical response to antidepressants in the entire EMBARC sample, and evaluating whether an upregulated brain arousal is particularly characteristic for responders to antidepressants.
Key Words: EMBARC; Electroencephalogram; VIGALL 2.1; Major Depressive Disorder; Brain Arousal; Regulation; EEG-vigilance