title: In vivo hippocampal subfield volumes in schizophrenia and bipolar disorder.
abstract: BACKGROUND
  Hippocampal dysfunction and volume reductions have been reported in patients with schizophrenia and bipolar disorder. The hippocampus consists of anatomically distinct subfields. We investigated to determine whether in vivo volumes of hippocampal subfields differ between clinical groups and healthy control subjects.
  
  
  METHODS
  Clinical examination and magnetic resonance imaging were performed in 702 subjects (patients with schizophrenia spectrum [n = 210; mean age, 32.0 ± 9.3 (SD) years; 59% male], patients with bipolar spectrum [n = 192; mean age, 35.5 ± 11.5 years; 40% male] and healthy control subjects [n = 300; mean age, 35.3 ± 9.9 years; 53% male]). Hippocampal subfield volumes were estimated with FreeSurfer. General linear models were used to explore diagnostic differences in hippocampal subfield volumes, covarying for age, intracranial volume, and medication. Post hoc analyses of associations to psychosis symptoms (Positive and Negative Syndrome Scale) and cognitive function (verbal memory [California Verbal Learning Test, second edition] and IQ [Wechsler Abbreviated Scale of Intelligence]) were performed.
  
  
  RESULTS
  Patient groups had smaller cornu ammonis (CA) subfields CA2/3 (left, p = 7.2 × 10(-6); right, p = 2.3 × 10(-6)), CA4/dentate gyrus (left, p = 1.4 × 10(-5); right, p = 2.3 × 10(-6)), subiculum (left, p = 3.7 × 10(-6); right, p = 2.8 × 10(-8)), and right CA1 (p = .006) volumes than healthy control subjects, but smaller presubiculum volumes were found only in patients with schizophrenia (left, p = 6.7 × 10(-5); right, p = 1.6 × 10(-7)). Patients with schizophrenia had smaller subiculum (left, p = .035; right, p = .031) and right presubiculum (p = .002) volumes than patients with bipolar disorder. Smaller subiculum volumes were related to poorer verbal memory in patients with bipolar disorder and healthy control subjects and to negative symptoms in patients with schizophrenia.
  
  
  CONCLUSIONS
  Hippocampal subfield volume reductions are found in patients with schizophrenia and bipolar disorder. The magnitude of reduction is greater in patients with schizophrenia, particularly in the hippocampal outflow regions presubiculum and subiculum.
authors.affiliation: Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway. Electronic address: unn.haukvik@medisin.uio.no.
authors.forename: Unn K
authors.initials: UK
authors.lastname: Haukvik
authors.affiliation: Department of Psychology, University of, Oslo, Norway; Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: Lars T
authors.initials: LT
authors.lastname: Westlye
authors.affiliation: Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.
authors.forename: Lynn
authors.initials: L
authors.lastname: Mørch-Johnsen
authors.affiliation: Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.
authors.forename: Kjetil N
authors.initials: KN
authors.lastname: Jørgensen
authors.affiliation: Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.
authors.forename: Elisabeth H
authors.initials: EH
authors.lastname: Lange
authors.affiliation: Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, California; Department of Radiology, University of California, San Diego, School of Medicine, La Jolla, California.
authors.forename: Anders M
authors.initials: AM
authors.lastname: Dale
authors.affiliation: Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Melle
authors.affiliation: Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: Ole A
authors.initials: OA
authors.lastname: Andreassen
authors.affiliation: Norwegian Centre for Mental Disorders Research K.G. Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of, Oslo, Norway; Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Agartz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology; D001714:Bipolar Disorder / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000188:drug therapy / Q000473:pathology*; D012559:Schizophrenia / Q000188:drug therapy / Q000473:pathology*; D055815:Young Adult
keywords: Hippocampus; MRI; Neuroanatomy; Psychosis; Subiculum; Verbal memory