Functional Connectivity Alterations of Within and Between Networks in Schizophrenia: A Retrospective Study.

Brain functional connectivity is altered in several brain disorders. Looking for these changes may help in better understanding the disorder effects, its diagnostic and treatment. Our brain can be organized into distinct functional modules, known as resting-state networks (RSNs). These RSNs include visual, somatomotor (SM), fronto-parietal, dorsal attention, ventral attention, default mode (DMN), and limbic functional systems. In this study, we examined the alteration of functional connectivity in schizophrenia disorder considering these brain RSNs. The functional connections were classified in two groups, the inter- and intra-network connections. Inter-network connections are defined as the links between pairs of regions from two different brain subnetworks, whereas intra- network connections are determined as the connections between pairs of regions inside each network. Our analysis indicated that the functional connectivity strengths of intra-network connections reduced more in schizophrenia. It was also found that the connection between the limbic network and others is more disrupted compared to other inter-network links. These findings can help us in better understanding the effect of schizophrenia on the brain and therefore its treatment.