Ruminative Tendency Relates to Ventral Striatum Functionality: Evidence From Task and Resting-State fMRI

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Ruminative responding, characterized by repetitive negative thinking, impedes adaptive coping strategies.
• The ventral striatum/nucleus accumbens (VS/NAcc) mediates reward-directed behaviors crucial for alleviating depressive states.
• Previous research has not investigated the relationship between trait rumination and VS/NAcc functionality.

Purpose of the Study:

• To investigate the association between trait rumination and VS/NAcc function.
• To determine if rumination moderates VS/NAcc activity in response to reward.
• To examine VS/NAcc functionality during a ruminative state.

Main Methods:

• Trait rumination was assessed using the Rumination Response Scale (RRS).
• fMRI was employed in 80 participants (community and major depressive disorder patients) to measure VS/NAcc function during reward anticipation and resting-state.
• Statistical analyses controlled for depressive symptom severity.

Main Results:

• RRS scores showed a positive correlation with VS/NAcc response to reward.
• Higher RRS scores were associated with increased resting-state functional connectivity between the VS/NAcc and the left orbitofrontal cortex.
• This connectivity was dependent on the ruminative state.

Conclusions:

• Ruminative tendencies are associated with altered VS/NAcc function related to reward processing.
• Findings support the view of rumination as a habitual impairment in selecting adaptive, rewarding strategies.
• This highlights a potential neural mechanism underlying the link between rumination and depressive states.