Disrupted Large-Scale Brain Network Connectivity in Prolonged Grief Disorder: Relationship With Grief-Related...

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Large-scale brain network dysfunction is implicated in neuropsychiatric disorders.
• Disrupted network interactions may underlie prolonged grief disorder (PGD) symptoms.

Purpose of the Study:

• To investigate resting-state functional connectivity (rsFC) differences between brain networks in individuals with PGD and those with integrated grief.
• To explore the relationship between brain network connectivity and PGD symptom severity.

Main Methods:

• A cross-sectional functional magnetic resonance imaging (fMRI) study compared rsFC in older adults with probable PGD (n=42) and integrated grief (n=45).
• Eight large-scale networks were analyzed, with rsFC strength between pairs computed.
• Fractional amplitude of low-frequency fluctuations (fALFF) assessed within-network differences, and relationships with clinical symptoms were explored.

Main Results:

• Individuals with PGD showed higher rsFC between the salience network (SN) and default mode network (DMN) compared to controls (p<0.05 corrected).
• This SN-DMN connectivity positively correlated with grief severity and avoidance.
• Broader between-network connectivity disruptions were associated with intrusive thoughts, yearning, and avoidance symptoms in PGD.

Conclusions:

• Aberrant SN-DMN connectivity is a neurobiological correlate of grief severity and avoidance in PGD.
• Widespread brain network connectivity disruptions are linked to core PGD symptoms, suggesting a role for network dysfunction in the disorder's pathophysiology.