title: Neuroanatomical abnormalities before and after onset of psychosis: a cross-sectional and longitudinal MRI comparison.
abstract: BACKGROUND
  Psychotic disorders, such as schizophrenia, are associated with neuroanatomical abnormalities, but whether these predate the onset of symptoms or develop progressively over the course of illness is unclear. We investigated this issue with MRI to study people with prodromal symptoms who are at ultra high-risk for the development of psychosis.
  
  
  METHODS
  We did two comparisons, cross-sectional and longitudinal. For the cross-sectional comparison, 75 people with prodromal signs of psychosis were scanned with MRI. After at least 12 months of follow-up, 23 (31%) had developed psychosis and 52 (69%) had not. Baseline MRI data from these two subgroups were compared. For the longitudinal comparison, 21 of the ultra high-risk individuals were scanned again with MRI after at least 12 months. Ten of these had developed psychosis and 11 had not. MRI data from baseline and follow-up were compared within each group of people.
  
  
  RESULTS
  In the cross-sectional comparison, compared with people who did not develop psychosis, those who did develop the disorder had less grey matter in the right medial temporal, lateral temporal, and inferior frontal cortex, and in the cingulate cortex bilaterally. In the longitudinal comparison, when re-scanned, individuals who had developed psychosis showed a reduction in grey matter in the left parahippocampal, fusiform, orbitofrontal and cerebellar cortices, and the cingulate gyri. In those who had not become psychotic, longitudinal changes were restricted to the cerebellum.
  
  
  CONCLUSIONS
  Some of the grey-matter abnormalities associated with psychotic disorders predate the onset of frank symptoms, whereas others appear in association with their first expression.
authors.affiliation: Cognitive Neuropsychiatry Research and Academic Unit, and Melbourne Neuropsychiatry Centre, Mental Health Programme, Department of Psychiatry, University of Melbourne and Sunshine Hospital, Victoria, Melbourne, Australia. cpant@unimelb.edu.au
authors.forename: Christos
authors.initials: C
authors.lastname: Pantelis
authors.forename: Dennis
authors.initials: D
authors.lastname: Velakoulis
authors.forename: Patrick D
authors.initials: PD
authors.lastname: McGorry
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Wood
authors.forename: John
authors.initials: J
authors.lastname: Suckling
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Phillips
authors.forename: Alison R
authors.initials: AR
authors.lastname: Yung
authors.forename: Edward T
authors.initials: ET
authors.lastname: Bullmore
authors.forename: Warrick
authors.initials: W
authors.lastname: Brewer
authors.forename: Bridget
authors.initials: B
authors.lastname: Soulsby
authors.forename: Patricia
authors.initials: P
authors.lastname: Desmond
authors.forename: Philip K
authors.initials: PK
authors.lastname: McGuire
mesh_terms: D000328:Adult; D001921:Brain / Q000002:abnormalities*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D011237:Predictive Value of Tests; D011618:Psychotic Disorders / Q000175:diagnosis / Q000473:pathology*; D012306:Risk