A preliminary study of the dysregulation of the resting networks in first-episode medication-naive adolescent depression.

Recent developments in depression studies have heightened the need for investigating adolescent major depressive disorder (MDD). Many previous neuroimaging studies used task designs and found consistent results in the dysfunction of brain regions in depressed adolescent patients. In this study, we aimed to evaluate the topological properties of brain functional networks of adolescents with MDD from an integrated view. Using resting state functional magnetic resonance imaging (fMRI), graph theory was applied to construct the resting networks in 16 first-episode and unmedicated adolescents with MDD and 16 healthy controls (HC). Our results showed that the topological properties of depressed adolescents' networks were significantly disrupted compared with HC. Dysregulation of brain regions were found in the anterior cingulate cortex, dorsolateral, medial and inferior prefrontal cortex, insula, amygdala, and the temporal cortices. Furthermore, the connectivity degree of amygdala related functional connection was positively correlated with the duration of depression. Detection and estimation of these functional impairments may advance our current understanding of the pathophysiological mechanism of adolescent MDD.