title: Does co-morbid obsessive-compulsive disorder modify the abnormal language processing in schizophrenia patients? An FMRI study.
abstract: BACKGROUND
  Impaired language processing is one of the most replicated findings in functional brain studies of schizophrenia (SCH). This is demonstrated by reduced activations in left prefrontal language areas (i.e., BA44/45, the inferior frontal gyrus, IFG) presented as decreased language lateralization. This finding was documented both in chronic as well as in first-episode SCH patients, arguing for a neurobiological marker for SCH. In a previous study, we demonstrated the specificity of this finding to SCH patients when compared to obsessive-compulsive disorder (OCD) patients in whom language processing was similar to healthy controls. Since a sizable proportion of SCH patients also meet DSM-IV criteria for OCD, we further sought to elucidate whether OCD attenuates abnormal prefrontal language lateralization in this unique group of schizo-obsessive patients compared to their non-OCD-SCH counterparts.
  
  
  METHODS
  We used functional magnetic resonance imaging (fMRI) to investigate regional activation and language lateralization in the left and right IFG and inter-hemispheric functional connectivity (FC) during a language task of auditory verb generation in 14 SCH patients with OCD, compared to 17 SCH patients without OCD, 13 OCD patients and 14 healthy controls.
  
  
  RESULTS
  No between-group differences were found in the behavioral measurements of word generation. However, while OCD patients were indistinguishable from healthy volunteers, a similarly reduced lateralization in the IFG and diminished inter-hemispheric FC was noted in the two SCH groups with and without OCD.
  
  
  CONCLUSIONS
  The co-occurrence of OCD in SCH does not attenuate abnormal processing of language as reflected by regional IFG activity and FC. These results further support the notion that these language processing abnormalities are characteristic of SCH and that SCH-OCD combined psychopathology is more akin to SCH than to OCD.
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center , Tel Aviv , Israel.
authors.forename: Maya
authors.initials: M
authors.lastname: Bleich-Cohen
authors.affiliation: Research Unit, Tirat Carmel Mental Health Center , Tirat Carmel , Israel ; Rappaport Faculty of Medicine, Technion - Israel Institute of Technology , Haifa , Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Poyurovsky
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center , Tel Aviv , Israel ; Sackler Faculty of Medicine, Tel Aviv University , Tel Aviv , Israel ; School of Psychological Sciences, Tel Aviv University , Tel Aviv , Israel ; Sagol School of Neuroscience, Tel Aviv University , Tel Aviv , Israel.
authors.forename: Talma
authors.initials: T
authors.lastname: Hendler
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University , Tel Aviv , Israel ; Clinical Psychopharmacology Unit, Tel Aviv Community Mental Health Center , Tel Aviv , Israel.
authors.forename: Ronit
authors.initials: R
authors.lastname: Weizman
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center , Tel Aviv , Israel ; Sackler Faculty of Medicine, Tel Aviv University , Tel Aviv , Israel.
authors.forename: Haggai
authors.initials: H
authors.lastname: Sharon
keywords: OCD; fMRI; inferior frontal gyrus; language; schizo-obsessive; schizophrenia