title: Hypofrontality in schizophrenia: a meta-analysis of functional imaging studies.
abstract: OBJECTIVE
  Hypofrontality is not a well-replicated finding in schizophrenia either at rest or under conditions of task activation.
  
  
  METHODS
  Studies comparing whole brain and frontal blood flow/metabolism in schizophrenic patients and normal controls were pooled. Voxel-based studies were also combined to examine the pattern of prefrontal activation in schizophrenia.
  
  
  RESULTS
  Whole brain flow/metabolism was reduced in schizophrenia to only a small extent. Resting and activation frontal flow/metabolism were both reduced with a medium effect size. Duration of illness significantly moderated resting hypofrontality, but the moderating effects of neuroleptic treatment were consistent with an influence on global flow/metabolism only. Pooling of voxel-based studies did not suggest an abnormal pattern of activation in schizophrenia.
  
  
  CONCLUSIONS
  Meta-analysis supports resting hypofrontality in schizophrenia. Task-activated hypofrontality is also supported, but there is little from voxel-based studies to suggest that this is associated with an altered pattern of regional functional architecture.
authors.affiliation: Fulbourn Hospital, Cambridge, UK.
authors.forename: K
authors.initials: K
authors.lastname: Hill
authors.forename: L
authors.initials: L
authors.lastname: Mann
authors.forename: K R
authors.initials: KR
authors.lastname: Laws
authors.forename: C M E
authors.initials: CM
authors.lastname: Stephenson
authors.forename: I
authors.initials: I
authors.lastname: Nimmo-Smith
authors.forename: P J
authors.initials: PJ
authors.lastname: McKenna
mesh_terms: D005625:Frontal Lobe / Q000098:blood supply*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D049268:Positron-Emission Tomography; D012559:Schizophrenia / Q000188:drug therapy* / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon