Although individuals at clinical high risk (CHR) for schizophrenia may not demonstrate comprehensive abnormalities in cortical grey matter, small to moderate correlations have been observed between grey matter intensity and neuropsychological deficits. The results, published in Schizophrenia Research, are part of the longitudinal Youth Mental Health Risk and Resilience Study (YouR Study), which was designed to identify neurobiological and psychological predictors of risk for psychosis.
Katia Zikidi, MSc, of the Institute for Neuroscience and Psychology at the University of Glasgow in the United Kingdom, and colleagues applied a whole-brain approach to magnetic resonance imaging data that involved the measurement of grey matter intensity in 70 regions of interest and preserved participant-specific topology, thus allowing the independent study of local grey matter intensity and cortical thickness.
The study recruited a total of 114 participants who were categorized as being CHR, 39 participants who did not fulfill CHR criteria (CHR-negative group), and 49 healthy controls. CHR status was evaluated with the Comprehensive Assessment of At-Risk Mental State and the Schizophrenia Proneness Instrument. Tests that examined emotion recognition, working memory, and attention, along with the Brief Assessment of Cognition in Schizophrenia Battery, were administered as well. Role and social functioning, along with premorbid adjustment, were also evaluated.
There were no significant differences in grey matter intensity or cortical thickness observed among CHR participants compared with individuals who were CHR-negative and healthy controls. Circumscribed abnormalities in grey matter intensity, however, were revealed in the visual and frontal cortex of the CHR participants. Furthermore, in the CHR participants, small to moderate correlations were reported between grey matter intensity and neuropsychological deficits.
The study may have been limited by the lack of assessment of negative symptoms or inclusion of follow-up data.
The investigators concluded that CHR participants may not exhibit comprehensive abnormalities in grey matter. Additional research is warranted to determine whether changes in grey matter intensity and thickness are potential biomarkers for the development of psychosis and continued poor psychosocial functioning among individuals who were categorized as being CHR.
Disclosures: Multiple study authors reported declarations of competing interest given research support and fees paid by pharmaceutical companies.
Zikidi K, Gajwani R, Gross J, et al. Grey-matter abnormalities in clinical high-risk participants for psychosis [published online November 15, 2019]. Schizophr Res. doi:10.1016/j.schres.2019.08.034