Rumination mediates the relationship between structural variations in ventrolateral prefrontal cortex and sensitivity to negative life events

Abstract

Individuals have different levels of stress sensitivity. An individual's predisposition to experience negative life events (NLEs) may make him/her more vulnerable to a series of psychopathological and physical diseases. However, the neuroanatomical correlates of individual differences in sensitivity to NLEs remain unknown. In this study, voxel-based morphometry was used to identify the gray matter (GM) associations of individual differences in sensitivity to NLEs measured by adolescent self-rating life events checklist. Results showed that there was a positive association between individual NLEs sensitivity and regional GM volume (rGMV) in the ventrolateral prefrontal cortex (VLPFC). GM was mostly evident in the left frontal operculum and a small part of the left middle frontal gyrus. This region was thought to play an important role in introception. Importantly, our study revealed that rumination served as a mediator between the rGMV of the VLPFC and individual NLEs sensitivity. These findings suggest that people with greater VLPFC might be more inclined to ruminate and the ruminative response style might make them more sensitive to NLEs.

Keywords: ASLEC; CRT; CVD; DV; FO; GM; IFG; MNI; MR; MRI; Montreal Neurological Institute; NLEs; PTSD; ROI; RRS; RSQ; SAS; SD; SDS; SPM; VBM; VLPFC; WM; adolescent self-rating life events checklist; cardiovascular disease; combined Raven’s test; coping style; dependent variable; frontal operculum; gray matter; individual differences; inferior frontal gyrus; magnetic resonance; magnetic resonance imaging; negative life events; post-traumatic stress disorder; rGMV; region of interest; regional GM volume; response style questionnaire; rumination (or ruminative) responses scale; s.e.; self-rating anxiety scale; self-rating depression scale; standard deviation; standard error; statistical parametric mapping; stress sensitivity; ventrolateral prefrontal cortex; voxel-based morphometry; white matter.