title: First-episode psychosis is characterized by failure of deactivation but not by hypo- or hyperfrontality.
abstract: BACKGROUND
  It is not known whether first-episode psychosis is characterized by the same prefrontal cortex functional imaging abnormalities as chronic schizophrenia.
  
  
  METHODS
  Thirty patients with a first episode of non-affective functional psychosis and 28 healthy controls underwent functional magnetic resonance imaging (fMRI) during performance of the n-back working memory task. Voxel-based analyses of brain activations and deactivations were carried out and compared between groups. The connectivity of regions of significant difference between the patients and controls was also examined.
  
  
  RESULTS
  The first-episode patients did not show significant prefrontal hypo- or hyperactivation compared to controls. However, they showed failure of deactivation in the medial frontal cortex. This area showed high levels of connectivity with the posterior cingulate gyrus/precuneus and parts of the parietal cortex bilaterally. Failure of deactivation was significantly greater in first-episode patients who had or went on to acquire a DSM-IV diagnosis of schizophrenia than in those who did not, and in those who met RDC criteria for schizophrenia compared to those who did not.
  
  
  CONCLUSIONS
  First-episode psychosis is not characterized by hypo- or hyperfrontality but instead by a failure of deactivation in the medial frontal cortex. The location and connectivity of this area suggest that it is part of the default mode network. The failure of deactivation seems to be particularly marked in first-episode patients who have, or progress to, schizophrenia.
authors: Benito Menni CASM, Barcelona, Spain.
authors: A
authors: A
authors: Guerrero-Pedraza
authors: P J
authors: PJ
authors: McKenna
authors: J J
authors: JJ
authors: Gomar
authors: S
authors: S
authors: Sarró
authors: R
authors: R
authors: Salvador
authors: B
authors: B
authors: Amann
authors: M I
authors: MI
authors: Carrión
authors: R
authors: R
authors: Landin-Romero
authors: J
authors: J
authors: Blanch
authors: E
authors: E
authors: Pomarol-Clotet
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D054022:Cerebrum / Q000503:physiopathology*; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D009415:Nerve Net; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000503:physiopathology; D011618:Psychotic Disorders / Q000175:diagnosis / Q000503:physiopathology*; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D055815:Young Adult