Zhu H, Yuan M, Qiu C, et al. - In the current study, researchers examined resting-state functional MRI (rs-fMRI) from 57 unmedicated survivors with chronic posttraumatic stress disorder (PTSD) and 59 matched trauma-exposed healthy controls (TEHCs) in order to establish a neurobiological signature of PTSD from the connectivity of large-scale brain networks. Further, they sought to clarify the brain network mechanisms of PTSD. The node-to-network connectivity extracted and a feature vector with a dimensionality of 864 (108 nodes× 8 networks) was obtained to describe each individual's functional connectivity profile. PTSD patients were then distinguished from TEHCs using multivariate pattern analysis with a relevance vector machine. Relatively high precision was achieved in distinguishing PTSD patients vs TEHCs at the individual level. This performance illustrates that rs-fMRI-derived multivariate classification based on large-scale brain networks can afford potential signatures both to aid clinical diagnosis and to unveil the underlying brain network mechanisms of PTSD induced by natural disasters.