Neurocognitive functioning in parents of schizophrenia patients: Attentional and executive performance vary with genetic loading

• Published in: Psychiatry research Vol. 230; no. 3; pp. 885 - 891
• Main Authors: Schulze-Rauschenbach, Svenja, Lennertz, Leonhard, Ruhrmann, Stephan, Petrovsky, Nadine, Ettinger, Ulrich, Pukrop, Ralf, Dreher, Jan, Klosterkötter, Joachim, Maier, Wolfgang, Wagner, Michael
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 30.12.2015
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Attention - physiology; Cognition; Cognition - physiology; Endophenotype; Endophenotypes; Executive Function - physiology; Female; Genetics; Humans; Male; Middle Aged; Neuropsychological Tests; Neuropsychology; Parents; Parents - psychology; Psychiatry; Risk Factors; Schizophrenia; Schizophrenia - genetics; Young Adult; Schizophrenia; Genetics; Cognition; Neuropsychology; Parents; Endophenotype
• ISSN: 0165-1781; 1872-7123
• DOI: 10.1016/j.psychres.2015.11.031

Abstract Neuropsychological deficits are candidate endophenotypes of schizophrenia which can assist to explain the neurocognitive impact of genetic risk variants. The identification of endophenotypes is often based on the familiality of these phenotypes. Several studies demonstrate neuropsychological deficits in unaffected biological relatives of schizophrenia patients without differentiating between genetic and non-genetic factors underlying these deficits. We assessed N =129 unaffected biological parents of schizophrenia patients, N =28 schizophrenia patients (paranoid subtype), and N =143 controls without a family history of schizophrenia with an extensive neuropsychological test battery. Direct comparison of N =22 parents with an ancestral history of schizophrenia (more likely carriers, MLC) and N =17 of their spouses without such a history (less likely carriers, LLC) allowed the separation of genetic and non-genetic aspects in cognition. Overall, parents showed significant deficits in neuropsychological tasks from all cognitive domains with medium effect sizes. Direct comparisons of MLC- and LLC-parents showed that attentional and executive tasks were most strongly affected by genetic loading. To conclude, unaffected parents of schizophrenia patients showed modest yet significant impairments in attention, memory, and executive functioning. In particular, attentional and executive impairments varied most strongly with genetic loading for schizophrenia, prioritising these dysfunctions for genotype-endophenotype analyses.