title: Saccadic eye movement task identifies cognitive deficits in children with schizophrenia, but not in unaffected child relatives.
abstract: BACKGROUND
  The delayed oculomotor response (DOR) task requires response inhibition followed by movement of gaze towards a known spatial location without a current stimulus. Abnormalities in response inhibition and in the spatial accuracy of the eye movement are found in individuals with schizophrenia and in many of their relatives, supporting the use of these saccadic abnormalities as endophenotypes in genetic studies. It is unknown whether school-age children, either with psychosis or as relatives of a schizophrenic proband, can be included.
  
  
  METHODS
  One hundred eighty-seven children, ages 5.8-16.0 years - 45 children with childhood-onset schizophrenia, 64 children with a first-degree relative with schizophrenia, and 84 typically developing children - completed DOR tasks with 1 and 3 second delays.
  
  
  RESULTS
  Children with childhood-onset schizophrenia demonstrated impaired response inhibition and impaired spatial accuracy compared to both relatives and typicals; however, relatives and typicals did not differ from each other.
  
  
  CONCLUSIONS
  Children with childhood-onset schizophrenia have saccadic abnormalities similar to those found in adults with schizophrenia, supporting the continuity of executive function deficits in childhood-onset with adolescent and adult-onset schizophrenia. However, saccadic tasks are not sensitive to genetic risk in non-psychotic children and 6-15-year-old children should not be included in genetic studies utilizing this endophenotype.
authors.affiliation: University of Colorado Health Sciences Center, CO, USA. randy.ross@uchsc.edu
authors.forename: Randal G
authors.initials: RG
authors.lastname: Ross
authors.forename: Shari
authors.initials: S
authors.lastname: Heinlein
authors.forename: Gary O
authors.initials: GO
authors.lastname: Zerbe
authors.forename: Allen
authors.initials: A
authors.lastname: Radant
mesh_terms: D000293:Adolescent; D001288:Attention; D002648:Child; D002872:Chromosome Deletion; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D003072:Cognition Disorders / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology; D005260:Female; D005820:Genetic Testing; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009949:Orientation; D010641:Phenotype; D011930:Reaction Time / Q000235:genetics; D018570:Risk Assessment; D012438:Saccades / Q000235:genetics*; D012559:Schizophrenia / Q000175:diagnosis* / Q000235:genetics; D012565:Schizophrenic Psychology; D012569:Schizotypal Personality Disorder / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology