Temperament and character as schizophrenia-related endophenotypes in non-psychotic siblings

Abstract

Background-Quantitative endophenotypes are needed to better understand the pathogenesis of schizophrenia. The psychobiological model of temperament and character suggests that personality traits are heritable and regulated by brain systems influencing schizophrenia susceptibility. Thus, measures of temperament and character may serve as schizophrenia-related endophenotypes in individuals with schizophrenia and their non-psychotic siblings.Methods-Individuals with schizophrenia (n=35), their non-psychotic siblings (n=34), controls (n=63), and their siblings (n=56) participated in a study of the clinical, cognitive and neuromorphological characteristics of schizophrenia. A mixed-model approach assessed group differences on the Temperament and Character Inventory (TCI). Neurocognitive deficits and psychopathology were correlated with the TCI. Configurations of TCI domains were examined using a generalized linear model.Results-Individuals with schizophrenia and their siblings had higher harm avoidance than controls and their siblings. Individuals with schizophrenia had lower self-directedness and cooperativeness, and higher self-transcendence than their non-psychotic siblings, controls, and the siblings of controls. Neurocognition was not related to temperament and character in individuals with schizophrenia or either control group. In non-psychotic siblings, self-directedness and cooperativeness were correlated with working memory and crystallized IQ.Conclusion-Evidence supports harm avoidance as a schizophrenia-related endophenotype. An increased risk of schizophrenia may be associated with asociality (configured as high harm avoidance and low reward dependence), schizotypy (configured as low self-directedness, low cooperativeness, and high self-transcendence), and neurocognitive deficits (poor executive functioning, working/ Reprint Requests: Dr. Matthew J. Smith, Northwestern University, Feinberg School of Medicine, Department of Psychiatry and Behavioral Sciences, 446 East Ontario Street, Suite 7-200, Chicago, IL 60611. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access

Fiber connectivity between the striatum and cortical and subcortical regions is associated with temperaments in Chinese males

“…Extreme/abnormal personality traits (especially temperaments) are common characteristics of a wide spectrum of prevalent personality and psychiatric disorders (Richter and Brandstrom, 2009;Svrakic et al, 1993), such as depression (Celikel et al, 2009;Farmer et al, 2003;Sandi and Richter-Levin, 2009), bipolar disorder (Olvera et al, 2009), borderline personality disorder (Barnow et al, 2007), obsessive-compulsive disorder (Ettelt et al, 2008), and schizophrenia (Hori et al, 2008;Smith et al, 2008). These disorders have been found to be accompanied by abnormal/pathological neurobiological changes in the brain (Hazlett et al, 2005;Nakamura et al, 2005).…”

Current suicidality and previous suicidal attempts in patients with schizophrenia are associated with different dimensions of temperament and character

“…Previous studies with suicide attempters, diagnosed otherwise, also described high scores on this dimension (Bulik et al, 1999;Becerra et al, 2005;Yumru et al, 2008), although it was not uniform finding (Perroud et al, 2010;Joyce et al, 2010). This dimension has been associated with intensity of positive symptoms on PANSS (Hori et al, 2008;Smith et al, 2008), as well as in this group of patients (Aukst- Margetić et al, 2011). Individuals scoring high on Self-transcendence can be characterized as spiritual, unpretentious, creative and humble (Cloninger et al, 1993).…”

“…Individuals scoring high on Self-transcendence can be characterized as spiritual, unpretentious, creative and humble (Cloninger et al, 1993). On the other hand, high Self-transcendence combined with low Self-directedness (the dimension that is typically low in patients with schizophrenia) (Smith et al, 2008;Ohi et al, 2012), may be linked to immaturity, fragile ego-boundaries and magical thinking (Cloninger et al, 1993;Svrakic and Cloninger, 2010). Psychopathological expression of fragile ego-boundaries might be reflected in phenomena of depersonalization and derealization that showed association with high Self-transcendence (Smith et al, 2008;Hori et al, 2008), and are also associated with proneness to suicidal attempt (Zikić et al, 2009).…”

“…This dimension reflects personality features such as responsibility, purposefulness, resourcefulness and self-acceptance (Cloninger et al, 1993). Self-directedness is typically low in patients with depression and in patients with schizophrenia (Abrams et al, 2004;Smith et al, 2008). Moreover, it is the most significant predictor of the patients' level of functioning (Eklund et al, 2004).…”

“…temperament) and developmental aspects (i.e. character) and interacts with psychopathologic as well as with psychosocial variables (Cloninger et al, 1993;Hori 2008;Smith et al, 2008). The association of personality with suicide risk in the population of psychiatric patients has been demonstrated (Calati et al, 2008;Giegling et al, 2009).…”