title: Schizotypy-Independent and Schizotypy-Modulated Cognitive Impairments in Unaffected First-Degree Relatives of Schizophrenia-spectrum Patients.
abstract: OBJECTIVE
  The aim of the study was to compare the neurocognitive profile of unaffected first-degree relatives of schizophrenia patients with control individuals, controlling for different schizotypal traits.
  
  
  METHODS
  One hundred and fifteen adult unaffected first-degree relatives of schizophrenia-spectrum patients and 122 controls were tested for schizotypy with the Schizotypal Personality Questionnaire. They also underwent a thorough neurocognitive assessment with a range of tasks covering several aspects of executive functioning. Between-group differences in cognition were examined first with multivariate analysis of variance and then with a series of multivariate analyses of covariance, including the schizotypal dimensions as covariates.
  
  
  RESULTS
  The relatives had higher scores on all schizotypal dimensions compared with controls and poorer planning, problem solving, strategy formation and working memory, irrespective of schizotypal traits. They also scored lower in executive working memory and verbal fluency. The difference in executive working memory was sensitive to the effects of paranoid and negative schizotypy (both dimensions abolished the between-group difference) whereas the difference in verbal fluency was sensitive only to the effects of paranoid schizotypy. Neither cognitive-perceptual nor disorganized schizotypy accounted for any differences in neurocognition between relatives and the controls.
  
  
  CONCLUSIONS
  Impairments in planning, problem solving, strategy formation and working memory are "core" impairments in the schizophrenia-spectrum, possibly due to high heritability effects in these functions. Impairments in executive working memory and verbal fluency are associated with paranoid and negative schizotypy, possibly due to alterations in a common fronto-temporo-parietal neural network.
authors.affiliation: Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno 74100, Crete, Greece.
authors.forename: Chrysoula
authors.initials: C
authors.lastname: Zouraraki
authors.affiliation: Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno 74100, Crete, Greece.
authors.forename: Penny
authors.initials: P
authors.lastname: Karamaouna
authors.affiliation: Department of Psychology, Faculty of Social Sciences, University of Crete, Rethymno 74100, Crete, Greece.
authors.forename: Leda
authors.initials: L
authors.lastname: Karagiannopoulou
authors.forename: Stella G
authors.initials: SG
authors.lastname: Giakoumaki
mesh_terms: D000328:Adult; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000209:etiology*; D005190:Family / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales; D012569:Schizotypal Personality Disorder / Q000145:classification / Q000150:complications* / Q000235:genetics*
keywords: Assessment; Fluency (verbal/nonverbal); Personality and personality disorders; Schizophrenia