title: Major depression and electrovestibulography.
abstract: OBJECTIVE
  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.
authors: Monash Alfred Psychiatry Research Centre, Monash University Central Clinical School and the Alfred Hospital , Melbourne, Victoria Australia.
authors: Brian J
authors: BJ
authors: Lithgow
authors: Amber L
authors: AL
authors: Garrett
authors: Zahra M
authors: ZM
authors: Moussavi
authors: Caroline
authors: C
authors: Gurvich
authors: Jayashri
authors: J
authors: Kulkarni
authors: Jerome J
authors: JJ
authors: Maller
authors: Paul B
authors: PB
authors: Fitzgerald
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D003865:Major Depressive Disorder / Q000150:complications / Q000175:diagnosis*; D004431:Ear, External; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015837:Vestibular Diseases / Q000175:diagnosis* / Q000209:etiology; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: biological markers; depression; humans; major depressive disorder; neurobiology