title: Decreased prefrontal Myo-inositol in major depressive disorder.
abstract: BACKGROUND
  Postmortem studies have shown robust prefrontal cortex glial losses and more subtle neuronal changes in major depressive disorder (MDD). Earlier proton magnetic resonance spectroscopy (1H-MRS) studies of the glial marker myo-inositol in MDD were subject to potential confounds. The primary hypothesis of this study was that MDD patients would show reduced prefrontal/anterior cingulate cortex levels of myo-inositol.
  
  
  METHODS
  Thirteen nonmedicated moderate-severe MDD patients and 13 matched control subjects were studied (six male, seven female per group). Proton magnetic resonance spectroscopy stimulated echo acquisition mode spectra (3.0 T; echo time=168 msec; mixing time=28 msec; repetition time=3000 msec) were obtained from prefrontal/anterior cingulate cortex. Metabolite data were adjusted for tissue composition.
  
  
  RESULTS
  Patients with MDD showed significantly lower myo-inositol/creatine ratios (.94+/-.23) than control subjects (1.32+/-.37) [F(1,23)=6.9; p=.016].
  
  
  CONCLUSIONS
  These data suggest a reduction of myo-inositol in prefrontal/anterior cingulate cortex in MDD, which could be a consequence of glial loss or altered glial metabolism. Additional in vivo studies of glial markers could add to the understanding of the pathophysiology of MDD.
authors.affiliation: Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada. Nick.Coupland@ualberta.ca
authors.forename: Nick J
authors.initials: NJ
authors.lastname: Coupland
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Ogilvie
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Hegadoren
authors.forename: Peter
authors.initials: P
authors.lastname: Seres
authors.forename: Chris C
authors.initials: CC
authors.lastname: Hanstock
authors.forename: Peter S
authors.initials: PS
authors.lastname: Allen
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001923:Brain Chemistry; D001931:Brain Mapping; D016022:Case-Control Studies; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D003865:Major Depressive Disorder / Q000378:metabolism*; D005260:Female; D006801:Humans; D007294:Inositol / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000378:metabolism*
chemical_list: D001224:Aspartic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline