title: Increased inferior frontal activation during word generation: a marker of genetic risk for schizophrenia but not bipolar disorder?
abstract: During verbal-fluency tasks, impairments in performance and functional abnormalities in the inferior frontal cortex have been observed in both schizophrenia patients and their unaffected relatives. We sought to examine whether such functional abnormalities are a specific marker of genetic vulnerability to schizophrenia. We studied a sample of 132 subjects, comprising 39 patients with schizophrenia, 10 unaffected monozygotic (MZ) cotwins of schizophrenia probands, 28 patients with bipolar disorder, 7 unaffected MZ cotwins of bipolar disorder probands and 48 healthy controls. Blood oxygen level-dependent response was measured using functional magnetic resonance imaging during the performance of an overt verbal-fluency task with two levels of task difficulty, in a cytoarchitectonic region of interest encompassing Brodmann areas 44 and 45 bilaterally. Patients with schizophrenia and the unaffected MZ cotwins of schizophrenia probands showed increased activation in the inferior frontal cortex relative to healthy controls and bipolar patients. Increased engagement of the inferior frontal cortex during verbal-fluency may thus be a marker of genetic vulnerability to schizophrenia.
authors.affiliation: Institute of Psychiatry, King's College London, London, United Kingdom. s.costafreda@iop.kcl.ac.uk
authors.forename: Sergi G
authors.initials: SG
authors.lastname: Costafreda
authors.forename: Cynthia H Y
authors.initials: CH
authors.lastname: Fu
authors.forename: Marco
authors.initials: M
authors.lastname: Picchioni
authors.forename: Fergus
authors.initials: F
authors.lastname: Kane
authors.forename: Colm
authors.initials: C
authors.lastname: McDonald
authors.forename: Diana P
authors.initials: DP
authors.lastname: Prata
authors.forename: Sridevi
authors.initials: S
authors.lastname: Kalidindi
authors.forename: Muriel
authors.initials: M
authors.lastname: Walshe
authors.forename: Vivienne
authors.initials: V
authors.lastname: Curtis
authors.forename: Elvira
authors.initials: E
authors.lastname: Bramon
authors.forename: Eugenia
authors.initials: E
authors.lastname: Kravariti
authors.forename: Nicolette
authors.initials: N
authors.lastname: Marshall
authors.forename: Timothea
authors.initials: T
authors.lastname: Toulopoulou
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Barker
authors.forename: Anthony S
authors.initials: AS
authors.lastname: David
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Brammer
authors.forename: Robin M
authors.initials: RM
authors.lastname: Murray
authors.forename: Philip K
authors.initials: PK
authors.lastname: McGuire
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000473:pathology*; D001931:Brain Mapping; D004200:Diseases in Twins; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D012559:Schizophrenia / Q000150:complications / Q000235:genetics* / Q000473:pathology*; D013064:Speech Disorders / Q000209:etiology / Q000473:pathology; D014705:Verbal Behavior / Q000502:physiology*
chemical_list: D010100:Oxygen