title: White matter volume changes in people who develop psychosis.
abstract: BACKGROUND
  Grey matter changes have been described in individuals who are pre- and peri-psychotic, but it is unclear if these changes are accompanied by changes in white matter structures.
  
  
  OBJECTIVE
  To determine whether changes in white matter occur prior to and with the transition to psychosis in individuals who are pre-psychotic who had previously demonstrated grey matter reductions in frontotemporal regions.
  
  
  METHODS
  We used magnetic resonance imaging (MRI) to examine regional white matter volume in 75 people with prodromal symptoms. A subset of the original group (n=21) were rescanned at 12-18 months to determine white matter volume changes. Participants were retrospectively categorised according to whether they had or had not developed psychosis at follow-up.
  
  
  RESULTS
  Comparison of the baseline MRI data from these two subgroups revealed that individuals who later developed psychosis had larger volumes of white matter in the frontal lobe, particularly in the left hemisphere. Longitudinal comparison of data in individuals who developed psychosis revealed a reduction in white matter volume in the region of the left fronto-occipital fasciculus. Participants who had not developed psychosis showed no reductions in white matter volume but increases in a region subjacent to the right inferior parietal lobule.
  
  
  CONCLUSIONS
  The reduction in volume of white matter near the left fronto-occipital fasciculus may reflect a change in this tract in association with the onset of frank psychosis.
authors.affiliation: Melbourne Neuropsychiatry Centre, Level 2, Royal Melbourne Hospital, 3050 Australia. mark.walterfang@mh.org.au
authors.forename: Mark
authors.initials: M
authors.lastname: Walterfang
authors.forename: Philip K
authors.initials: PK
authors.lastname: McGuire
authors.forename: Alison R
authors.initials: AR
authors.lastname: Yung
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Phillips
authors.forename: Dennis
authors.initials: D
authors.lastname: Velakoulis
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Wood
authors.forename: John
authors.initials: J
authors.lastname: Suckling
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: Patrick D
authors.initials: PD
authors.lastname: McGorry
authors.forename: Christos
authors.initials: C
authors.lastname: Pantelis