The whole-brain connectome landscape in patients with schizophrenia: A systematic review and meta-analysis of graph theoretical characteristics

The alterations of connectome in schizophrenia have been reported, but the results remain inconsistent. We conducted a systematic review and random-effects meta-analysis on structural or functional connectome MRI studies comparing global graph theoretical characteristics between schizophrenia and healthy controls. Metaregression and subgroup analyses were performed to examine confounding effects. Based on the included 48 studies, structural connectome in schizophrenia showed a significant decrease in segregation (lower clustering coefficient and local efficiency, Hedge's g= -0.352 and -0.864, respectively) and integration (higher characteristic path length and lower global efficiency, Hedge's g= 0.532 and -0.577 respectively). The functional connectome showed no difference between groups except gamma. Moderator analysis indicated that clinical and methodological factors exerted a potential effect on the graph theoretical characteristics. Our analysis revealed a weaker small-worldization trend in structural connectome of schizophrenia. For the relatively unchanged functional connectome, more homogenous and high-quality studies are warranted to elucidate whether the change was blurred by heterogeneity or the presentation of pathophysiological reconfiguration.

Automated summary

The study conducted a systematic review and meta-analysis on connectome alterations in schizophrenia. The results showed that there were significant differences in the structural connectome, with lower segregation and integration characteristics in schizophrenia. However, there were no significant differences in the functional connectome between schizophrenia and healthy controls, except for gamma. Moderator analysis indicated that clinical and methodological factors influenced the findings. More studies are needed to clarify the changes in the functional connectome.