title: Developmental abnormalities of the hippocampus in first-episode schizophrenia.
abstract: BACKGROUND
  The human hippocampus becomes visible during the first trimester and folds to form the hippocampal fissure (HF) in the second trimester. The walls of this fissure fuse by 30 weeks, although small residual cavities can occur if development is disrupted. The primary purpose of this study was to determine if hippocampal fissures are evident in schizophrenia. A second goal was to assess the association between HF size and premorbid and clinical features of the illness.
  
  
  METHODS
  Magnetic resonance imaging scans were obtained on 33 patients with first-episode schizophrenia and 19 healthy volunteers. Hippocampal fissures were measured using semi-automated procedures, and hippocampi were manually traced. Birth history and premorbid functioning were assessed using maternal report.
  
  
  RESULTS
  Patients had a significantly larger mean HF volume and a nonsignificantly smaller hippocampal volume. Hippocampal fissure size was significantly associated with poor educational achievement and with anxiety-depression symptoms during the onset of illness. Smaller hippocampal size was associated with poor premorbid adjustment.
  
  
  CONCLUSIONS
  Larger HF size and an association between low educational achievement and enlarged HFs suggest abnormal neurodevelopment in schizophrenia. The association between HF size and anxiety-depression symptoms suggests that hippocampal abnormalities underlying HF dilatation may be a predisposing factor for increased stress sensitivity.
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Geoffrey N
authors.initials: GN
authors.lastname: Smith
authors.forename: Donna J
authors.initials: DJ
authors.lastname: Lang
authors.forename: Lili C
authors.initials: LC
authors.lastname: Kopala
authors.forename: Jocelyne S
authors.initials: JS
authors.lastname: Lapointe
authors.forename: Peter
authors.initials: P
authors.lastname: Falkai
authors.forename: William G
authors.initials: WG
authors.lastname: Honer
mesh_terms: D000328:Adult; D004522:Educational Status; D006624:Hippocampus / Q000002:abnormalities* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D009929:Organ Size; D012559:Schizophrenia / Q000209:etiology* / Q000473:pathology; D012565:Schizophrenic Psychology; D013315:Stress, Psychological / Q000209:etiology; D013997:Time Factors