title: Persistence, diagnostic specificity and genetic liability for context-processing deficits in schizophrenia.
abstract: Context-processing deficits have been shown in schizophrenia during first-episode, medication-naïve status, that persist after short-term antipsychotic treatment and also in first-degree relatives of individuals with schizophrenia. To confirm longer term persistence of deficits, we examined schizophrenia patients (n=63) during first-episode, medication-naïve status through to one-year follow-up, compared to healthy control (n=83) and non-schizophrenia psychosis comparison (n=47) groups, as well as unaffected first-degree relatives of individuals with schizophrenia (n=31). Context-processing ability was assessed by performance on the AX-CPT (Continuous Performance Test) at baseline, 8 weeks, 6 months, and 1 year (relatives only at baseline). Reaction time, error rates and signal detection indices (d'-context) of context processing were analyzed. Linear discriminant analyses (LDA) on early timepoints (baseline, 8 weeks) were conducted to predict confirmatory diagnosis (schizophrenia vs. psychosis control) at 6 months. Schizophrenia patients showed evidence of impaired context-processing relative to both the healthy and psychosis comparator groups at baseline and continued through to 1 year. While context-processing impairments persisted in schizophrenia patients through one year, the impairments in psychosis controls, which were more modest at baseline, remitted at follow-up. First-degree relatives showed deficits that were intermediate between the schizophrenia and healthy control groups. LDA showed 67% classification rates for distinguishing schizophrenia from non-schizophrenia psychosis. The persistence, diagnostic specificity and association with genetic liability give support for context processing impairments serving as a cognitive endophenotype for schizophrenia and evaluation of context processing could contribute to diagnostic assessments.
authors.affiliation: Department of Psychiatry, Thomas Detre Hall of the Western Psychiatric Institute and Clinic, University of Pittsburgh, 3811 O'Hara Street, Pittsburgh, PA 15213, USA.
authors.forename: Annette E
authors.initials: AE
authors.lastname: Richard
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of California, Davis, 2230 Stockton Blvd., Sacramento, CA 95817, USA; Department of Psychology, University of California, Davis, 135 Young Hall, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Cameron S
authors.initials: CS
authors.lastname: Carter
authors.affiliation: Department of Psychology, Princeton University, Green Hall, Princeton, NJ 08540, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Cohen
authors.affiliation: Department of Psychiatry, Thomas Detre Hall of the Western Psychiatric Institute and Clinic, University of Pittsburgh, 3811 O'Hara Street, Pittsburgh, PA 15213, USA. Electronic address: chory@upmc.edu.
authors.forename: Raymond Y
authors.initials: RY
authors.lastname: Cho
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology / Q000235:genetics; D005190:Family; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D012559:Schizophrenia / Q000150:complications* / Q000235:genetics; D012565:Schizophrenic Psychology; D013997:Time Factors; D055815:Young Adult