title: Structural changes in hippocampal subfields in major depressive disorder: a high-field magnetic resonance imaging study.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) has shown lower hippocampal volume in major depressive disorder (MDD). Preclinical and postmortem studies show that chronic stress and MDD may affect hippocampal subfields differently, but MRI spatial resolution has previously been insufficient to measure subfield volumes.
  
  
  METHODS
  Twenty MDD participants (9 unmedicated and 11 medicated, both > 6 months) and 27 healthy control subjects were studied. We used T2-weighted two-dimensional fast spin echo and T1-weighted three-dimensional magnetization prepared rapid acquisition gradient-echo sequences at 4.7 T to compare hippocampal subfield volumes at .09 μL voxel volume.
  
  
  RESULTS
  Unmedicated MDD participants had a lower dentate gyrus volume than control subjects or medicated MDD participants and a lower cornu ammonis (CA1-3) volume in the hippocampal body subregion than control subjects.
  
  
  CONCLUSIONS
  Hippocampal volumes in unmedicated MDD showed evidence of localization to specific subfields and subregions, findings that appear, on the surface, consistent with preclinical evidence for localized mechanisms of hippocampal neuroplasticity. Strengths include in vivo measurement of entire hippocampal subfields and separation between unmedicated and medicated MDD. Limitations include power to control for multiple comparisons and that MRI landmarks approximate the subfields defined by cellular microstructure.
authors: Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada.
authors: Yushan
authors: Y
authors: Huang
authors: Nicholas J
authors: NJ
authors: Coupland
authors: R Marc
authors: RM
authors: Lebel
authors: Rawle
authors: R
authors: Carter
authors: Peter
authors: P
authors: Seres
authors: Alan H
authors: AH
authors: Wilman
authors: Nikolai V
authors: NV
authors: Malykhin
mesh_terms: D000293:Adolescent; D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003865:Major Depressive Disorder / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000187:drug effects* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents