Social support and brain function are mediators between trauma as a youth and major depressive disorder (MDD), suggests a study presented in a poster at the virtual 2021 American Psychiatric Association Annual Meeting.
Researchers from the school of medicine at Southeast University, Nanjing, China, investigated differences between 102 participants with MDD and 36 healthy control subjects. Assessment measures included resting-state functional magnetic resonance imaging (fMRI) scans and self-reports of trauma experienced during youth and social support.
Participants with MDD had more trauma and less social support compared with healthy control subjects, according to the findings. Additionally, participants with MDD demonstrated decreased amplitude of low-frequency fluctuation in the right posterior cingulate and the left postcentral gyrus regions of the brain. They also showed decreased functional connectivity in the left posterior cingulate, bilateral postcentral gyrus, and middle temporal gyrus.
Functional connectivity in the left posterior cingulate mediated the link between sexual abuse and baseline score on the 24-item Hamilton Rating Scale for Depression, researchers reported. The association between trauma experienced early in life and MDD, as well as age of MDD onset, was mediated by social support alone or in combination with functional connectivity in the left posterior cingulate region.
“Amplitude of low-frequency fluctuation and functional connectivity in the differential brain regions were able to distinguish MDD from healthy controls,” researchers wrote.
Combining indicators of trauma during youth, social support, and brain function, they advised, would even more accurately distinguish participants with MDD from healthy controls.
“This study further confirmed that [youth] trauma, social support, and abnormal functions of the brain, especially posterior cingulate, are involved in the underlying mechanisms of MDD,” researchers concluded. “Social support and brain functional indicators are serial mediators between [youth] trauma and MDD, and the combination of relevant indicators of [youth] trauma, social support, and brain functions could distinguish MDD from healthy controls well.”