Cognitive alterations in patients with non-affective psychotic disorder and their unaffected siblings and parents

Authors

  • J. Meijer,

    1. Department of Psychiatry, Academic Medical Centre University of Amsterdam, Amsterdam
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    • Contributed equally.

  • C. J. P. Simons,

    1. Department of Psychiatry and Psychology, School for Mental Health and Neuroscience, European Graduate School of Neuroscience, South Limburg Mental Health Research and Teaching Network, Maastricht University Medical Centre, Maastricht
    2. GGzE, Institute for Mental Health Care Eindhoven en de Kempen, Eindhoven
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    • Contributed equally.

  • P. J. Quee,

    1. University Medical Center Groningen, Department of Psychiatry and Rob Giel Research Center, University of Groningen, Groningen
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  • K. Verweij,

    1. Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
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  • GROUP Investigators

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Dr Inez Myin-Germeys, Department of Psychiatry and Psychology, Maastricht University Medical Centre, P.O. Box 616 (Loc. Vijverdal), 6200 MD Maastricht, The Netherlands.
E-mail: i.germeys@maastrichtuniversity.nl

Abstract

Meijer J, Simons CJP, Quee PJ, Verweij K, GROUP Investigators. Cognitive alterations in patients with non-affective psychotic disorder and their unaffected siblings and parents.

Objective:  The purpose of this study was to examine a range of cognitive measures as candidate phenotypic liability markers for psychosis in a uniquely large sample of patients with psychosis, their unaffected relatives and control subjects.

Method:  Patients with non-affective psychosis (= 1093), their unaffected siblings (n = 1044), parents (n = 911), and controls (n = 587) completed a comprehensive cognitive test battery. Cognitive functioning was compared using tests of verbal learning and memory, attention/vigilance, working memory, processing speed, reasoning and problem solving, acquired knowledge, and social cognition. Age- and gender-adjusted z-scores were compared between groups using mixed-model analyses of covariance. Clinically relevant impairment (−1 and −2 SD from control mean) was compared between subject groups.

Results:  Patients performed significantly worse than controls in all cognitive domains (z-range −0.26 to −1.34). Siblings and parents showed alterations for immediate verbal learning, processing speed, reasoning and problem solving, acquired knowledge, and working memory (z-range −0.22 to −0.98). Parents showed additional alterations for social cognition. Prevalence of clinically relevant impairment in relatives ranged from 50% (−1 SD criterion) to 10% (−2 SD criterion).

Conclusion:  Cognitive functioning is a candidate intermediate phenotype given significant small to large alterations in patients and intermediate alterations in first-degree relatives.

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