Fronto-Limbic Alterations in Negatively Biased Attention in Young Adults with Subthreshold Depression.

Haijiang Li,Jiangzhou Sun,Jiang Qiu,Qinglin Zhang,Dongtao Wei

doi:10.3389/fpsyg.2017.01354

Abstract

Attentional bias toward negative stimuli has been observed in major depression disorders (MDDs). Imaging studies suggest the engagement of fronto-limbic regions like amygdala, anterior cingulate cortex (ACC), and lateral prefrontal cortex, is related to negatively biased attention. However, neural correlates of attentional bias for negative stimuli in individuals with subthreshold depression (SubD), that is individuals who have clinically relevant depressive symptoms but do not fulfill the criteria for MDD, remain unclear. Here, we used functional neuroimaging and the dot-probe task to elucidate the neural substrates of negatively biased attention among individuals with SubD. Behavioral results found that individuals with SubD allocated more attention toward negative stimuli relative to neutral stimuli, which were not observed among non-depressed controls (NCs). Imaging results found greater amygdala and rostral ACC activity in attentional bias toward negative stimuli among participants with SubD compared to NCs; Additionally, participants with SubD showed reduced engagement of bilateral inferior frontal gyrus compared with NCs in the attentional processing of negative stimuli. Together, these results suggest that alteration of fronto-limbic systems relative to controls, known to be related to negative detection and attentional control, is associated with negatively biased attention in individuals with SubD.

Highlights

Major depression disorder (MDD) is a leading cause of lifetime disability and will be the foremost leading contributor to the global burden of disease (Ferrari et al, 2013; Smith, 2014)
The results showed that participants with subthreshold depression (SubD) exhibited greater activation in the left amygdala (peak MNI coordinate: −21, −3, −27; t = 4.12, p(corrected) < 0.05; Cluster size = 135 mm3; Figure 1B and Table 2) and left rostral anterior cingulate cortex (ACC) (peak MNI coordinate: −9, 36, −6; t = 4.03, p(corrected) < 0.05; Cluster size = 378 mm 3; Figure 1A and Table 2) than the non-depressed controls (NCs)
Differential activation between participants with SubD and NCs was examined for the contrast of all negative trials versus neutral trials

Summary

Introduction

Major depression disorder (MDD) is a leading cause of lifetime disability and will be the foremost leading contributor to the global burden of disease (Ferrari et al, 2013; Smith, 2014). Considering high prevalence and recurrence rate of MDD, it is critical to identify the factors that contribute to increased risk for depression (Joormann et al, 2007; Gotlib et al, 2014). Subthreshold depression (SubD), which was known as a risk factor of MDD (Cuijpers and Smit, 2004), has received considerable attention in recent years (Ma et al, 2013; Buntrock et al, 2016; Li et al, 2016). SubD is defined as individuals who have clinically relevant depressive symptoms but do not fulfill the criteria for MDD (Cuijpers and Smit, 2004; Cuijpers et al, 2007). As the prodromal phase of MDD (Eaton et al, 1995), SubD can predict the occurrence of depressive disorders within 2 years (Karsten et al, 2011). SubD, provides an ideal model for understanding the pathophysiologic mechanisms of depression and for developing preventative options for patients with MDD

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