Alterations in large-scale functional networks in adult posttraumatic stress disorder: A systematic review and meta-analysis of resting-state functional connectivity studies

•This study is a systematic review of seed-based resting-state functional connectivity studies in PTSD.•PTSD is associated with abnormal communication among the DMN, AN and SMN.•Trauma may have long-lasting effects on the function of the DMN and AN regardless of whether it causes symptoms of PTSD.•Functional alterations in the SMN may be more specifically related to PTSD itself. Posttraumatic stress disorder (PTSD) is associated with dysfunction in large-scale brain functional networks, as revealed by resting-state functional connectivity studies. However, it remains unclear which networks have been most consistently affected and, more importantly, what role disease and trauma may play in the disrupted functional networks. We performed a systematic review of studies exploring network alterations using seed-based functional connectivity analysis, comparing individuals with PTSD to controls in general as well as trauma-exposed or nonexposed controls specifically, and quantitative meta-analysis was conducted when the number of studies was appropriately high. We found that hypoconnectivity within the default-mode network (DMN) as well as between the affective network (AN) and DMN were specifically associated with traumatic experience. Additionally, hyperconnectivity between the AN and somatomotor network (SMN) and between the DMN and SMN were specifically related to PTSD. Our results emphasize the effect of trauma itself on alterations in intrinsic brain networks and highlight disease-associated network alterations, which may help us better understand the neural mechanisms of trauma and PTSD.