Cognitive mechanisms underlying disorganization of thought in a genetic syndrome (47,XXY)

Van Rijn, Sophie; Aleman, André; De Sonneville, Leo; Swaab, Hanna

doi:10.1016/j.schres.2009.04.017

« Previous Next »Schizophrenia Research
Volume 112, Issue 1 , Pages 91-98, July 2009

Cognitive mechanisms underlying disorganization of thought in a genetic syndrome (47,XXY)

Sophie Van Rijn
- Leiden University, Clinical Child and Adolescent Studies, Wassenaarseweg 52, 2333 AK Leiden, The Netherlands
- University Medical Center Utrecht, Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
- Corresponding author. Leiden University, Faculty of Social Sciences, Department of Clinical Child and Adolescent Studies, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands.
André Aleman
- University of Groningen, BCN NeuroImaging Center, A. Deusinglaan 2, 9713 AW Groningen, The Netherlands
Leo De Sonneville
- Leiden University, Clinical Child and Adolescent Studies, Wassenaarseweg 52, 2333 AK Leiden, The Netherlands
Hanna Swaab
- Leiden University, Clinical Child and Adolescent Studies, Wassenaarseweg 52, 2333 AK Leiden, The Netherlands
- University Medical Center Utrecht, Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands

Received 1 December 2008; received in revised form 7 April 2009; accepted 12 April 2009. published online 18 May 2009.

Abstract

Because of the risk for development of psychopathology such as psychotic symptoms, it has been suggested that studying men with the XXY karyotype may help in the search for underlying cognitive, neural and genetic mechanisms. The aim of this study was to identify cognitive mechanisms that may contribute to disorganization of thought in XXY men.

A group of 24 XXY men and two non-clinical control groups (N=20, N=18) participated in the study. The level of disorganization of thought was measured using the Schizotypal Personality Questionnaire. We assessed IQ, lateralization of verbal information processing and executive functions including inhibition and mental flexibility.

XXY men with high levels of disorganization showed more severe impairments in mental flexibility and inhibition as compared to non-clinical controls and other XXY men. This subgroup also showed a stronger reduction in lateralization of verbal information processing. IQ measures did not differentiate XXY men with high versus low levels of disorganization.

These findings indicate that executive impairments in the domains of inhibition and mental flexibility might play a role in the increased vulnerability for disorganized thought in the XXY group. Reduced lateralization of verbal information processing points to non-optimal cerebral specialization in the XXY group, especially in XXY men with high levels of disorganization. This fits with deficits in brain functions most vulnerable to such maturational disruptions, i.e. executive dysfunctions. Our findings are in line with those reported for schizophrenia patients with thought disorder. We speculate that the underlying mechanisms of thought disorder probably are deficit specific rather than disorder specific.

Keywords: XXY, Klinefelter, Executive functioning, Thought disorder, Schizotypy, Lateralization