Decreased functional coupling within default mode network in major depressive disorder with childhood trauma

Childhood trauma (CT) has been supported to be a high-risk factor for major depressive disorder (MDD), but the neural mechanism linking CT and depression remains unclear. The aim of this study is to deepen our understanding of this issue by establishing the neuroimaging correlations between CT and depression. A sample of 123 MDD patients (91 with moderate-to-severe CT and 32 with no or low CT) and 79 healthy controls (HC, 33 with moderate-to-severe CT and 46 with no or low CT) participated. All participants completed assessments of depression level, anxiety, recent perceived stress, and resting-state functional MRI scan. Participants with moderate-to-severe CT showed elevated depression level and trait anxiety, and reduced spontaneous neural activity in left inferior temporal gyrus (ITG). Abnormalities of seed-based functional connectivity (FC) of left ITG – bilateral precuneus/posterior cingulate cortex (PCC), left middle temporal gyrus (MTG), left medial orbitofrontal cortex (mOFC), and bilateral medial prefrontal cortex (mPFC)/anterior cingulate cortex (ACC) were observed. CT was associated with decreased FCs in MDD, but with increased FCs in HC. The total altered FCs of left ITG – bilateral precuneus/PCC and left mOFC mediated relationship between CT and depression in MDD, and total altered FCs and trait anxiety have a significant chain mediation effect in the association between CT and depression in HC. These findings highlight the changes of default mode network (DMN) functions and trait anxiety as targets of CT. The decreased functional coupling within DMN may be involved in the mechanism of MDD following CT.