title: Duration of illness, regional brain morphology and neurocognitive correlates in schizophrenia.
abstract: BACKGROUND
  Previous studies examining brain effects of duration of illness in schizophrenia have focused on either cortical or subcortical structures. Hence this study sought to elucidate the regional grey matter changes (both cortical and subcortical) and neurocognitive correlates with increased duration of illness in a large sample of patients with schizophrenia using voxel-based morphometry.
  
  
  METHODS
  Ninety patients (72 males and 18 females) with DSM-IV diagnosis of schizophrenia were recruited and assessed using magnetic resonance imaging and a battery of neuropsychological tests.
  
  
  RESULTS
  A longer duration of illness was associated with smaller grey matter volumes in the left superior frontal gyrus, bilateral putamen, right superior temporal gyrus, right superior occipital gyrus as well as the right thalamus. No region showed increased grey matter volume above threshold with longer duration of illness. Longer duration of illness was correlated with poorer attention.
  
  
  CONCLUSIONS
  The grey matter reductions in different brain regions highlighted that a distributed network of cortical and subcortical regions was associated with duration of illness. This is consistent with neural models that implicate involvement of thalamo-cortical circuitry as the disruption in these neural pathways can result in specific deficits such as poorer attention. The results have implications for the understanding of brain changes in schizophrenia, and with further studies, may guide better tailored and targeted clinical management in terms of reducing the impact of duration of illness on neural substrates in schizophrenia in the future.
authors.affiliation: Research Division, Institute of Mental Health, Singapore. wai_yen_chan@imh.com.sg
authors.forename: Wai Yen
authors.initials: WY
authors.lastname: Chan
authors.forename: Ming Ying
authors.initials: MY
authors.lastname: Chia
authors.forename: Guo Liang
authors.initials: GL
authors.lastname: Yang
authors.forename: Puay San
authors.initials: PS
authors.lastname: Woon
authors.forename: Yih Yian
authors.initials: YY
authors.lastname: Sitoh
authors.forename: Simon Lowes
authors.initials: SL
authors.lastname: Collinson
authors.forename: Wieslaw Lucjan
authors.initials: WL
authors.lastname: Nowinski
authors.forename: Kang
authors.initials: K
authors.lastname: Sim
mesh_terms: D000328:Adult; D017668:Age of Onset; D001921:Brain / Q000473:pathology*; D003071:Cognition; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D055815:Young Adult