Schizophrenia is a complex psychiatric and brain disorder involving a wide range of cognitive, emotional, social function impairments and altered brain structure. Recent findings suggest a continuum approach that continuous symptoms and psychiatric disorder related traits can be integrated as risk features for the development of the corresponding disorders. Schizotypy refers to schizophrenia-like traits below clinical threshold in the general population. Therefore, the schizotypy construct not just serves as a conceptual guide for understanding the phenotypic and clinical variability associated with schizophrenia-spectrum vulnerability but also for understanding phenotypic complexity across clinical and subclinical groups. One of the phenotypic markers will be the potential change of brain structure and functional connectivity associated with the disorders. However, very little is known whether schizotypy is associated with specific changes in brain connectivity.
In order to bridge such a gap of knowledge, Dr. Raymond Chan and his team members from the Neuropsychology and Applied Cognitive Neuroscience (NACN) Laboratory, CAS Key Laboratory of Mental Health, the Chinese Academy of Sciences have examined the brain structural and functional connectivity changes associated with schizotypy. They recruited 87 participants with high level of schizotypal traits and 122 participants with low level of schizotypal traits to undergo both resting-state and diffusion tensor imaging scans. Their findings showed that individuals with high level of schizotypal traits exhibited increased structural connectivity probability within the task control network and within the default mode network; increased variability and decreased stability of functional connectivity within the default mode network and between the auditory network and the subcortical network; and decreased static mean functional connectivity strength mainly associated with the sensorimotor network, the default mode network and the task control network.
Taken together, these findings suggest that individuals with high level of schizotypal traits do exhibit both compensatory and deficient connectivity mainly associated with the default mode network, the task control network and the sensorimotor network. These findings therefore indicate the underlying brain connectivity adaptive changes in individuals with high level of schizotypal traits, and provide a possible neurobiological basis for the connectivity decompensation hypothesis in schizophrenia spectrum disorders. Dr. Chan has also been serving as one of the founding members of the Schizotypy Working Group of the ENIGMA to examine the structural changes associated with schizotypy, especially the subcortical regions. Moreover, Dr. Chan’s team is now pursuing a series of studies to examine whether these observed changes are specific to individuals with schizotypal traits or shared by individuals with other subclinical traits.
This study was supported by the National Key Research and Development Programme, the Beijing Municipal Science & Technology Commission Grant, the Beijing Training Project for the Leading Talents in S & T, the Strategic Priority Research Program (B) of the Chinese Academy of Science, and the CAS Key Laboratory of Mental Health, Institute of Psychology.
This study is now available online from Psychological Medicine
Wang, Y. M., Cai, X. L., Zhang, R. T., Zhang,Y. J., Zhou, H. Y., Wang, Y., Wang, Y., Huang, J., Wang, Y. Y., Cheung, E. F. C., Chan, R. C. K.* (2020).Altered brain structural and functional connectivity in schizotypy. Psychological Medicine, DOI: https://doi.org/10.1017/S0033291720002445
Wang, Y., Yan, Chao, Yin, D. Z., Fan, M. X., Cheung, E. F. C., Pantelis C., Chan, R. C. K.* (2015). Neurobiological changes of schizotypy: evidence from both volume based morphometric analysis and resting-state functional connectivity. Schizophrenia Bulletin, 41 (suppl 2): S444-S454
Wang, Y., Liu, W. H., Wei, X. H., Jiang, X. Q., Geng, F. L., Zou, L. Q., Lui, S. S. Y., Cheung, E. F. C., Pantelis, C., Chan, R. C. K.* (2016). Altered corticostriatal functional connectivity in individuals with high social anhedonia. Psychological Medicine, 46, 125-135.
Wang, Y., Ettinger, U.*, Meindl, T., Chan, R. C. K.* (2018). Association of schizotypy with striato-cortical functional connectivity and its asymmetry in healthy adults. Human Brain Mapping, 39:288–299.
Institute of Psychology