title: Normal birth weight variation is related to cortical morphology across the psychosis spectrum.
abstract: BACKGROUND
  Normal birth weight variation affects schizophrenia risk and cognitive performance in schizophrenia patients and healthy controls. Brain cortical anatomy is altered in psychotic disorders and in low birth weight subjects, but if birth weight variation relates to cortical morphology across the psychosis spectrum is not known.
  
  
  METHODS
  Magnetic Resonance Imaging brain scans and clinical-, neurocognitive-, and medical birth registry data were collected from 359 adults including patients with a DSM-IV diagnosis of schizophrenia (n = 90, mean age 29.4±10.2 [95% CI], 62% male), bipolar disorder (n = 79, age 29.4±11.8, 39% male) or other psychosis (n = 40, age 26.3±10.0, 56% male), and healthy controls (n = 140, age 30.8±12.0,53% male). We explored the relationship between whole-range birth weight variation and cortical surface area and thickness and their possible associations to cognitive performance.
  
  
  RESULTS
  Across all groups, lower birth weight was associated with smaller total surface area (t = 3.87, P = .0001), within specific regions of the temporal, parietal, and frontal cortex bilaterally. There were no associations between birth weight and cortical thickness, and no diagnosis by birth weight interaction effects on cortical thickness or surface area. Smaller cortical area (t = 2.50, P = .013) and lower birth weight (t = 2.53, P = .012) were significantly related to poorer working memory performance in all diagnostic groups except schizophrenia.
  
  
  CONCLUSIONS
  Birth weight relates to adult cortical surface area, but not cortical thickness, in patients across the psychosis spectrum and in healthy controls. Cortical area appears to be a diagnosis-independent general marker of early neurodevelopment, with a dose-response association to normal birth weight variation.
authors: *To whom correspondence should be addressed; PO Box 85 Vinderen, 0319 Oslo, Norway; tel: +47 22029800, fax: +47 22495862, e-mail: unn.haukvik@medisin.uio.no.
authors: Unn K
authors: UK
authors: Haukvik
authors: Lars M
authors: LM
authors: Rimol
authors: J Cooper
authors: JC
authors: Roddey
authors: Cecilie B
authors: CB
authors: Hartberg
authors: Elisabeth H
authors: EH
authors: Lange
authors: Anja
authors: A
authors: Vaskinn
authors: Ingrid
authors: I
authors: Melle
authors: Ole A
authors: OA
authors: Andreassen
authors: Anders
authors: A
authors: Dale
authors: Ingrid
authors: I
authors: Agartz
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000473:pathology* / Q000503:physiopathology; D001724:Birth Weight / Q000502:physiology*; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000254:growth & development; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009664:Norway; D011618:Psychotic Disorders / Q000473:pathology* / Q000503:physiopathology; D012042:Registries; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology
keywords: IQ; Magnetic Resonance Imaging; cortical area; neurodevelopment; schizophrenia; working memory