A Neuroanatomical Signature for Schizophrenia Across Different Ethnic Groups

Abstract

Schizophrenia is a disabling clinical syndrome found across the world. While the incidence and clinical expression of this illness are strongly influenced by ethnic factors, it is unclear whether patients from different ethnicities show distinct brain deficits. In this multicentre study, we used structural Magnetic Resonance Imaging to investigate neuroanatomy in 126 patients with first episode schizophrenia who came from 4 ethnically distinct cohorts (White Caucasians, African-Caribbeans, Japanese, and Chinese). Each patient was individually matched with a healthy control of the same ethnicity, gender, and age (±1 year). We report a reduction in the gray matter volume of the right anterior insula in patients relative to controls (P < .05 corrected); this reduction was detected in all 4 ethnic groups despite differences in psychopathology, exposure to antipsychotic medication and image acquisition sequence. This finding provides evidence for a neuroanatomical signature of schizophrenia expressed above and beyond ethnic variations in incidence and clinical expression. In light of the existing literature, implicating the right anterior insula in bipolar disorder, depression, addiction, obsessive-compulsive disorder, and anxiety, we speculate that the neuroanatomical deficit reported here may represent a transdiagnostic feature of Axis I disorders.

A combined VBM and DTI study of schizophrenia: bilateral decreased insula volume and cerebral white matter disintegrity corresponding to subinsular white matter projections unlinked to clinical symptomatology

“…However, reduced insular volume was also reported to differentiate schizophrenia patients from their healthy relatives (26), and it was even present in first episode psychosis (27). Decreased right anterior insula volume in schizophrenia patients was also shown to be independent of ethnicity and duration of illness, positive and negative scores and antipsychotic treatments (28). In our patient sample this result has been replicated.…”

Voxel-based morphometry: current perspectives

“…82 Remarkably, a smaller GM volume in this region has been found to be a consistent datum not only across different psychiatric diagnoses, as reported in the previous paragraph, 7 but also across different ethnic groups. 84 This is in line with the notion of a neuroanatomical signature of early SCZ above and beyond ethnic differences in the manifestation of the disease. 85 Moreover, the GM volume in the right anterior insula seems to be inversely related to both negative and positive symptomatology, such that the insula becomes smaller as symptoms become more severe.…”

Sex disparities in substance abuse research: Evaluating 23 years of structural neuroimaging studies

“…Current scientific consensus is that fundamental differences exist in brain structure and function possibly in response to sexually selective evolutionary pressures (Cahill, 2014a). Brain differences between sexes have been shown in terms of neurodevelopmental trajectories (Lenroot et al, 2007), structural morphometry (Clayton and Collins, 2014; Luders et al, 2009; Peelle et al, 2012; Watanabe et al, 2013), connectivity (Cahill, 2014b; Duarte-Carvajalino et al, 2012; Gong et al, 2015; Ingalhalikar et al, 2014), and molecular biology (Al Nadaf et al, 2010; Cahill, 2006; Jazin and Cahill, 2010; Wu et al, 2014). Patients with substance use disorder (SUD) demonstrate sex differences in many natural history features, including age of first use, rate of drug consumption escalation, quantity consumed, affect, and behavior (Becker et al, 2012; Eaton et al, 2012; Hernandez-Avila et al, 2004).…”