title: Intact speed of processing in a community-based sample of adults with high schizotypy: A marker of reduced psychosis risk?
abstract: Speed of processing is impaired in schizophrenia but intact in schizotypal college students. In view of this disparity, we investigated whether deficient processing speed was associated with schizotypy in adults from the general community. Data were drawn from the Western Australian Family Study of Schizophrenia, including 216 (non-clinical) adults from the general community, and a reference group with schizophrenia spectrum disorder (N=224). Schizotypal traits were assessed with the Schizotypal Personality Questionnaire, whilst processing speed was assessed with a digit-symbol coding task. Community controls had significantly higher digit symbol coding scores than patients with psychosis. However, both correlational and hierarchical regression analysis indicated a lack of association between Cognitive-perceptual, Interpersonal or Disorganized schizotypy traits and digit symbol coding performance. Relative to Australian norms there was also no evidence of a non-linear decline in coding in high schizotypes in young, mature or senior age groups. The results show that speed of information processing is unimpaired in high schizotypes from the general community. The possibility that intact processing speed in at-risk groups confers protection to psychosis onset is discussed. Assessing the trajectory of processing speed throughout development may provide a useful clinical screening tool to distinguish those at heightened risk of developing psychosis.
authors.affiliation: Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, University of Western Australia, Rear 50 Murray Street, Perth 6000, Australia. Electronic address: Johanna.badcock@uwa.edu.au.
authors.forename: Johanna C
authors.initials: JC
authors.lastname: Badcock
authors.affiliation: Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, University of Western Australia, Rear 50 Murray Street, Perth 6000, Australia. Electronic address: Melanie.Clark@uwa.edu.au.
authors.forename: Melanie L
authors.initials: ML
authors.lastname: Clark
authors.affiliation: Clinical Research Centre, North Metropolitan Health Service-Mental Health, Mount Claremont 6019, Australia. Electronic address: rebecca.pedruzzi@my.jcu.edu.au.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Pedruzzi
authors.affiliation: Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, University of Western Australia, Rear 50 Murray Street, Perth 6000, Australia. Electronic address: Vera.Morgan@uwa.edu.au.
authors.forename: Vera A
authors.initials: VA
authors.lastname: Morgan
authors.affiliation: Centre for Clinical Research in Neuropsychiatry, School of Psychiatry and Clinical Neurosciences, University of Western Australia, Rear 50 Murray Street, Perth 6000, Australia. Electronic address: Assen.Jablensky@uwa.edu.au.
authors.forename: Assen
authors.initials: A
authors.lastname: Jablensky
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010551:Personality / Q000235:genetics; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D011930:Reaction Time / Q000235:genetics*; D012111:Residence Characteristics; D012307:Risk Factors; D012569:Schizotypal Personality Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D011795:Surveys and Questionnaires; D014904:Western Australia / Q000453:epidemiology; D055815:Young Adult
keywords: Digit symbol coding; Resilience; Schizophrenia; Schizotypy; Speed of processing