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

Alon Erdman,Eva Gilboa-Schechtman,Ezequiel Diego Ais,Itamar Jalon,Eiran Vadim Harel,Rany Abend,Tomer Gazit,Talma Hendler,Moran Artzi,Hilik Levokovitz,Keren Avirame

doi:10.3389/fpsyt.2020.00067

Abstract

BackgroundRuminative responding involves repetitive and passive thinking about one’s negative affect. This tendency interferes with initiation of goal-directed rewarding strategies, which could alleviate depressive states. Such reward-directed response selection has been shown to be mediated by ventral striatum/nucleus accumbens (VS/NAcc) function. However, to date, no study has examined whether trait rumination relates to VS/NAcc functionality. Here, we tested whether rumination moderates VS/NAcc function both in response to reward and during a ruminative state.MethodsTrait rumination was considered dimensionally using Rumination Response Scale (RRS) scores. Our sample (N = 80) consisted of individuals from a community sample and from patients diagnosed with major depressive disorder, providing a broad range of RRS scores. Participants underwent fMRI to assess two modes of VS/NAcc functionality: 1) in response to reward, and 2) during resting-state, as a proxy for ruminative state. We then tested for associations between RRS scores and VS/NAcc functional profiles, statistically controlling for overall depressive symptom severity.ResultsRRS scores correlated positively with VS/NAcc response to reward. Furthermore, we noted that higher RRS scores were associated with increased ruminative-dependent resting-state functional connectivity of the VS/NAcc with the left orbitofrontal cortex.ConclusionsThese findings suggest that ruminative tendencies manifest in VS/NAcc reward- and rumination-related functions, providing support for a theoretical-clinical perspective of rumination as a habitual impairment in selection of rewarding, adaptive coping strategies.

Highlights

Rumination is conceptualized as a mode of responding to distress, involving repetitive and passive thinking about one’s negative affect [1]
A total of 80 adult participants (M age = 29.6 years, SD = 9.2; 45 females) took part in the study. This sample included 56 individuals sampled from the community and 24 patients diagnosed with major depressive disorder (MDD), which enabled a broad range of trait rumination scores to be collected
To verify that the chosen VS/NAcc Region Of Interest (ROI) corresponded to activation induced in the task in our sample, we conducted a whole-brain second-level analysis of the reward versus punishment contrast

Summary

Introduction

Rumination is conceptualized as a mode of responding to distress, involving repetitive and passive thinking about one’s negative affect [1]. A theoretical framework by Watkins and Nolen-Hoeksema [5] proposes that ruminative response to distress first starts as a goal-based coping mechanism aimed to improve an individual’s understanding of his own mental state, but eventually becomes habitual by being repeatedly conditioned with different distressing contexts. This habitual response may interfere with initiating alternative rewarding strategies which could alleviate one’s negative affect, further perpetuating a detrimental cycle [1, 6, 7]. Ruminative responding involves repetitive and passive thinking about one’s negative affect This tendency interferes with initiation of goal-directed rewarding strategies, which could alleviate depressive states. We tested whether rumination moderates VS/NAcc function both in response to reward and during a ruminative state

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Conclusion