title: The parahippocampal gyrus as a neural marker of early remission in first-episode psychosis: a voxel-based morphometry study.
abstract: BACKGROUND
  Outcome from psychotic disorders is heterogeneous with poor long-term clinical outcome associated with such markers as decreased internal capsule volume and increased ventricular volumes. No previous study has examined neuroimaging markers in relation to early remission.
  
  
  METHODS
  This neuroimaging study included 68 previously untreated first episode of psychosis (FEP) patients, of whom 28 achieved remission and 40 did not after six months of treatment, and 42 healthy controls. Using voxel-based morphometry (VBM), we set out to determine if specific neural correlates could be identified in FEP patients not achieving remission in a specialized early-intervention service.
  
  
  RESULTS
  Nonremitted patients had significant lower grey matter concentration (GMC) in the parahippocampal gyrus bilaterally compared to remitted patients. A classification model utilizing parahippocampal GMC correctly classified remission status 79% of the time and accounted for 56% of the variance. Moreover, GMC on the left (r=-0.35, p=0.004) and right (r=-0.47, p<0.0001) side correlated with social withdrawal while only the left side correlated with verbal memory (r=0.21, p=0.03).
  
  
  CONCLUSIONS
  Neural markers of early remission are present in first-episode patients. A better understanding of the neural etiology of psychosis and its relationship to outcome may encourage the search for new medications to help improve outcome in relation to the identified brain regions like the parahippocampal gyrus.
authors.affiliation: Brain Imaging Group, Douglas Mental Health University Institute, Frank B. Common Pavilion, Montreal, Quebec, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Bodnar
authors.forename: Philippe-Olivier
authors.initials: PO
authors.lastname: Harvey
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Malla
authors.forename: Ridha
authors.initials: R
authors.lastname: Joober
authors.forename: Martin
authors.initials: M
authors.lastname: Lepage
mesh_terms: D000328:Adult; D003071:Cognition; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D020534:Parahippocampal Gyrus / Q000473:pathology*; D010296:Parietal Lobe / Q000473:pathology; D011618:Psychotic Disorders / Q000473:pathology* / Q000523:psychology / Q000628:therapy*; D012074:Remission Induction; D013702:Temporal Lobe / Q000473:pathology; D013997:Time Factors; D016896:Treatment Outcome; D014705:Verbal Behavior; D055815:Young Adult