title: Neural markers of remission in first-episode schizophrenia: a volumetric neuroimaging study of the hippocampus and amygdala.
abstract: OBJECTIVE
  The temporolimbic region has been implicated in the pathophysiology in schizophrenia. More specifically, significantly smaller hippocampal volumes but not amygdala volumes have been identified at onset in first-episode schizophrenia (FES) patients. However, volumetric differences (namely, in the hippocampus) exhibit an ambiguous relationship with long-term outcome. So, we examined the relationship between hippocampus and amygdala volumes and early remission status.
  
  
  METHODS
  We compared hippocampus and amygdala volumes between 40 non-remitted and 17 remitted FES patients and 57 healthy controls. Amygdala and hippocampus were manually traced with the hippocampus additionally segmented into three parts: body, head, and tail. Remission was defined as mild or less on both positive and negative symptoms over a period of 6 consecutive months as per the 2005 Remission in Schizophrenia Working Group criteria.
  
  
  RESULTS
  A significant [group x structure x side] interaction revealed outcome groups differed in hippocampus tail volumes; significantly on the left (non-remitted=694+/-175 mm(3); remitted=855+/-133 mm(3); p=0.001) with a trend difference on the right (non-remitted=723+/-162 mm(3); remitted=833+/-126 mm(3); p=0.023). Groups did not differ in body, head, or amygdala volumes bi-laterally.
  
  
  CONCLUSIONS
  A smaller hippocampal tail volume may represent a neural marker in FES patients who do not achieve early remission after the first 6 months of treatment. The early identification of patients with poor outcome with respect to the hippocampus tail may encourage the search for new, more target-specific, medications in hope of improving outcome and moving us towards a better understanding of the pathophysiology of schizophrenia.
authors.affiliation: Brain Imaging Group, Douglas Mental Health University Institute, Montreal, Canada. michael.bodnar@douglas.mcgill.ca
authors.forename: Michael
authors.initials: M
authors.lastname: Bodnar
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Malla
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Czechowska
authors.forename: Audrey
authors.initials: A
authors.lastname: Benoit
authors.forename: Ferid
authors.initials: F
authors.lastname: Fathalli
authors.forename: Ridha
authors.initials: R
authors.lastname: Joober
authors.forename: Marita
authors.initials: M
authors.lastname: Pruessner
authors.forename: Jens
authors.initials: J
authors.lastname: Pruessner
authors.forename: Martin
authors.initials: M
authors.lastname: Lepage
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000473:pathology*; D000704:Analysis of Variance; D001931:Brain Mapping; D004467:Economics; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult