Cortical midline structures associated with rumination in women with PTSD

Elevated rumination, characterized by repetitive, negative self-focused cognition, is common in  posttraumatic stress disorder  (PTSD) and has been shown to predict the onset and maintenance of the disorder.  Neuroimaging research  has implicated cortical midline brain structures, including the rostral anterior  cingulate cortex  (rACC), posterior cingulate cortex (PCC), and isthmus cingulate (IsthCing), in rumination in healthy and depressed populations. While past research has revealed dysfunction in cortical midline regions in PTSD, no studies have yet investigated the structural and functional neural mechanisms underlying rumination in women with PTSD. In the current study, we used structural MRI and resting-state fMRI to examine relationships between rumination and brain volume, as well as resting-state  functional connectivity  (rsFC) of cortical midline structures in women with PTSD due to interpersonal trauma ( N  = 71). We performed  multiple linear regression  analyses to relate brain volume in rACC, PCC, and IsthCing regions to self-reported rumination, after controlling for age and total intracranial volume. We also conducted standard seed-based voxelwise rsFC analyses for significant regions identified in the structural analysis. We found a significant relationship between greater rumination and volume in the left IsthCing ( p  = .025). Results from the rsFC analyses revealed a significant relationship between greater rumination and diminished rsFC between the left IsthCing and left  precuneus  ( p FWE  < .05). These findings provide novel support for alterations in the  neural substrates  of ruminative thought in women with PTSD. More broadly, we discuss clinical implications for targeted interventions to reduce rumination through  psychotherapy  or non-invasive  brain stimulation .