Resting-state functional connectivity of the rostral and dorsal anterior cingulate cortex in older bereaved adults

Abstract

Background: Older adults are at higher risk of losing a loved one, with approximately 10 % developing prolonged grief disorder (PGD) after loss. PGD is characterized by distressing and impairing symptoms, reduced life quality, and increased suicide risk. While attentional processes may contribute to PGD pathophysiology, the rostral (rACC) and dorsal anterior cingulate cortex (dACC) appear to play different yet complementary roles in attention in the bereavement context. However, the respective contributions of the connectivity of these two regions in PGD symptom severity have never been evaluated. This study investigated the associations between PGD symptom severity and resting-state functional connectivity (rsFC) of the rACC and dACC.

Methods: Resting-state fMRI scans were collected from N = 81 older adults who experienced loss >1 year prior, along with the inventory of complicated grief (ICG). Seed-based voxel-wise rsFC analysis was performed to investigate associations between ICG total scores and rsFC for the rACC and dACC.

Results: Higher ICG scores were associated with increased rsFC between the rACC and left frontal areas and right rACC, and between the dACC and clusters in the posterior cingulate and parietal cortex. Individuals with probable PGD (ICG ≥ 30) exhibited greater increases in dACC-parietal cortex rsFC than those without (ICG < 30).

Conclusions: PGD symptom severity in bereaved older adults was associated with disruptions in rsFC patterns within and between brain regions related to impaired emotion regulation, memory processing, and attentional biases in grief, with stronger changes in individuals with probable PGD. These brain regions might serve as targets for future treatment development efforts.

Keywords: Attention; Functional connectivity; Inventory of complicated grief; Prolonged grief disorder; Resting-state MRI.