Affective traits and history of depression are related to ventral striatum connectivity

Abstract

Introduction: Studying remitted Major Depressive Disorder (rMDD) facilitates a better understanding of neural mechanisms for risk, given that confounding effects of active symptoms are removed. Disrupted functional connectivity has been reported in multiple networks in MDD. However, no study to date of rMDD has specifically examined connectivity of the ventral striatum (VS), a region highly implicated in reward and motivation. We investigated functional connectivity of the VS in individuals with and without a history of MDD, and in relation to affective personality traits.

Methods: Forty-two individuals with rMDD and 28 healthy controls across two sites completed resting-state fMRI and the Behavioral Inhibition System/Behavioral Activation System Scale. Voxel-wise, whole-brain comparisons were conducted across and between groups for four seeds: left and right inferior VS (VSi), left and right superior VS (VSs).

Results: VSs connectivity to temporal and subcortical regions including the putamen and amygdala was positive and greater in HCs compared to rMDD individuals. Across groups, VSi connectivity was positively correlated with trait reward-responsiveness in somatomotor regions. Across groups, VSs connectivity was positively correlated with trait drive, particularly in the putamen, parahippocampal, and inferior temporal gyrus, and was negatively associated with trait behavioral inhibition in the anterior cingulate, frontal gyri, and insula.

Limitations: Limitations include scanning at two sites and using multiple comparisons.

Discussion: Group connectivity differences emerged from the VSs rather than VSi. VSs showed associations with trait drive and behavioral inhibition, whereas VSi corrrelated with reward-responsiveness. Depression history and affective traits contribute meaningful and specific information about VS connectivity in understanding risk for MDD.

Keywords: Affective traits; Depression; Functional connectivity; Reward-responsiveness; Ventral striatum.

Figure 1

Network connectivity of the VS seeds across groups. The left inferior ventral striatum (A), left superior VS (B), and right superior VS (C) seeds are shown, t = 10. Right inferior VS connectivity was similar to left inferior VS and is not shown. The seeds are highlighted in yellow and each panel shows the extent of the network.

Figure 2

VSi connectivity relating to affective traits and diagnostic group. Several regions of connectivity to the LVSi (Panel A1) and RVSi (Panel A2) were positively correlated with BAS-RR. HCs had greater connectivity than rMDDs from the LVSi (Panel B1) and RVSi (Panel B2). All images display using threshold of p < .005 and k > 55.

Figure 3

VSs connectivity relating to affective traits and diagnostic group. Several regions of connectivity with the LVSs (Panel A1) and RVSs (Panel A2) were positively correlated with BAS-D. Several regions of connectivity with the LVSs (Panel B1) and RVSs (Panel B2) were negatively correlated with BIS. HCs had greater connectivity than rMDDs from the LVSs (Panel C1) and RVSs (Panel C2). Panel D displays the overlap (light blue) between connectivity regions that negatively related to BIS (dark blue) and were greater in HCs than rMDDs (green). All images display using a threshold of p < .005 and k > 55.