UC San Diego

Functional neuroimaging studies have advanced our understanding of the network dysfunctions related to major depressive disorder (MDD) in adults. However, our current understanding of these network alterations in adolescents very limited, especially in relation to the subgenual anterior cingulate cortex (ACC). The main goal of this study is to further our understanding of the role of the subgenual ACC in adolescents with depression during fear processing by examining how MDD affects subgenual ACC connectivity with other brain regions. Nineteen unmedicated adolescents diagnosed MDD and nineteen well- matched controls ages 13-17 years underwent a gender discrimination task during fMRI, where the participants viewed images of different intensities of fear. Whole brain analysis demonstrated that adolescents with depression showed decreased activation in the left precuneus, left ACC, and right precentral gyrus compared to normal controls when viewing faces showing stronger fearful emotions. Functional connectivity analysis showed : (1) increased connectivity between the right subgenual ACC and the left amygdala, (2) decreased connectivity between the right subgenual ACC and the left fusiform gyrus, right precuneus, right insula, and (3) decreased connectivity between the left subgenual ACC and the bilateral insula. Overall, our findings show that the subgenual ACC plays a key role in modulating perceptual and cognitive processes, and that, like adult depression, adolescent depression involves a disruption of networks involving the subgenual ACC. Our findings build towards a model of a disrupted network in clinically depressed adolescence such that low fear/neutral faces are deemed threatening and a wider network is recruited