title: Laterality and mental disorders in the postgenomic age--A closer look at schizophrenia and language lateralization.
abstract: Most people are right-handed and show left-hemispheric language lateralization, but a minority exhibits left-handedness and right-hemispheric language lateralization. This atypical laterality pattern is observed significantly more often in schizophrenia patients than in the general population, which led several authors to conclude that there is a genetic link between laterality and schizophrenia. It has even been suggested that a failure in the lateralization process, orchestrated by genes, could be the primary cause of schizophrenia. However, the molecular genetic evidence for a link between laterality and schizophrenia is weak. Recent genetic evidence indicates that schizophrenia is not a single disorder but a group of heritable disorders caused by different genotypic networks leading to distinct clinical symptoms. To uncover the link between schizophrenia and laterality we therefore suggest a paradigm shift where genetics are not mapped on schizophrenia as a whole but on discrete schizophrenia symptoms. In addition, we provide a critical evaluation of current theories on the genetic link between schizophrenia and brain asymmetry.
authors.affiliation: Institute of Cognitive Neuroscience, Biopsychology, Ruhr-University Bochum, Germany. Electronic address: sebastian.ocklenburg@rub.de.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ocklenburg
authors.affiliation: Institute of Cognitive Neuroscience, Biopsychology, Ruhr-University Bochum, Germany.
authors.forename: Onur
authors.initials: O
authors.lastname: Güntürkün
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen, Norway; Division of Psychiatry, Haukeland University Hospital, Bergen, Norway; Department of Radiology, Haukeland University Hospital, Bergen, Norway; NORMENT Center of Excellence, University of Bergen, Norway.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hugdahl
authors.affiliation: Department of Biological and Medical Psychology, University of Bergen, Norway.
authors.forename: Marco
authors.initials: M
authors.lastname: Hirnstein
mesh_terms: D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D007839:Functional Laterality / Q000502:physiology*; D005838:Genotype; D006801:Humans; D007802:Language; D012559:Schizophrenia / Q000235:genetics* / Q000503:physiopathology*
keywords: Auditory hallucinations; Dichotic listening; Genetics; Language lateralization; Schizophrenia