Major depression and electrovestibulography

Abstract

Objectives. No electrophysiological neuroimaging or genetic markers have been established that strongly relate to a diagnosis of major depression or its severity. The objective of this paper is to describe the preliminary evaluation of a potential new biomarker for depression utilizing the recording of electrical activity from the outer ear canal referred to as electrovestibulography (EVestG). Methods. Sensory oto-acoustic features were extracted from EVestG data to compare 31 healthy age- and gender-matched individuals as controls to 43 major depressive disorder (MDD) subjects (22 symptomatic (MDD-S), 21 reduced symptomatic (MDD-R)). The stimulus was a single supine-vertical translation. The six features examined were based on the measured firing pattern interval histogram and the shape of the average field potential response. Results. An unbiased classification accuracy of 85, 87 and 77% was achieved for separating Control from MDD-S, Control from MDD, and MDD-S from MDD-R groups respectively. Features used showed low but significant correlations (P < 0.05) with MADRS and CORE assessments. Conclusions. The results support the use of separate features for measuring MDD symptomatology versus diagnosing MDD, representing plausible different mechanisms of brain function in MDD-S and MDD-R. The first evidence of the successful application of sensory oto-acoustic features toward diagnosing and measuring the symptomatology of MDD is presented.

Key words::

• depression
• major depressive disorder
• neurobiology
• humans
• biological markers

Acknowledgements

We would like to thank all members of Monash Alfred Psychiatry Research Center who supported this research. This work was supported by grants from the Australian Research Council and National Health and Medical Research Council. Neural Diagnostics Pty Ltd was the industry partner in this research. PBF is supported by an NHMRC practitioner fellowship.

Statement of Interest

BL owns 1% of shares in Neural Diagnostics Pty Ltd. (ND) and acts as a consultant for ND.

Author Contributions

BL designed and carried out the experiments, analysed the data and wrote the original manuscript. ZM provided substantial edit and input to the manuscript.

AG carried out the experiments and was a PhD student at the time.

PF, CG, JK designed the experiments and performed the psychiatric assessments.

PF reviewed and provided substantial edit to the manuscript.

JM reviewed and edited the manuscript.

Supplemental material available online

Supplementary: Background, Methods, Figure 1, Discussion and References