title: White matter microstructure in schizophrenia: effects of disorder, duration and medication.
abstract: BACKGROUND
  Diffusion tensor magnetic resonance imaging studies in schizophrenia to date have been largely inconsistent. This may reflect variation in methodology, and the use of small samples with differing illness duration and medication exposure.
  
  
  OBJECTIVE
  To determine the extent and location of white matter microstructural changes in schizophrenia, using optimised diffusion tensor imaging in a large patient sample, and to consider the effects of illness duration and medication exposure.
  
  
  METHODS
  Scans from 76 patients with schizophrenia and 76 matched controls were used to compare fractional anisotropy, a measure of white matter microstructural integrity, between the groups.
  
  
  RESULTS
  We found widespread clusters of reduced fractional anisotropy in patients, affecting most major white matter tracts. These reductions did not correlate with illness duration, and there was no difference between age-matched chronically and briefly medicated patients.
  
  
  CONCLUSIONS
  The finding of widespread fractional anisotropy reductions in our larger sample of patients with schizophrenia may explain some of the inconsistent findings of previous, smaller studies.
authors.affiliation: Institute of Psychiatry, Department of Psychological Medicine, King's College London, PO 62, Denmark Hill, London SE5 9RJ, UK. r.kanaan@iop.kcl.ac.uk
authors.forename: Richard
authors.initials: R
authors.lastname: Kanaan
authors.forename: Gareth
authors.initials: G
authors.lastname: Barker
authors.forename: Michael
authors.initials: M
authors.lastname: Brammer
authors.forename: Vincent
authors.initials: V
authors.lastname: Giampietro
authors.forename: Sukhwinder
authors.initials: S
authors.lastname: Shergill
authors.forename: James
authors.initials: J
authors.lastname: Woolley
authors.forename: Marco
authors.initials: M
authors.lastname: Picchioni
authors.forename: Timothea
authors.initials: T
authors.lastname: Toulopoulou
authors.forename: Philip
authors.initials: P
authors.lastname: McGuire
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000188:drug therapy / Q000473:pathology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents