Aberrant resting-state functional connectivity in limbic and cognitive control networks relates to depressive rumination and mindfulness: A pilot study among adolescents with a history of depression

Background: Resting state functional connectivity (RSFC) research among adults indicates abnormalities within and between neural networks during acute depressive episodes, some of which are likely to remain into remission. The examination of RSFC among adolescents within the remitted state of MDD may implicate markers of illness course during a critical developmental window wherein secondary prevention can be implemented. Methods: RSFC data were collected on a 3.0T GE scanner from adolescents (12-18, M=15.61, SD=1.90; 57% female) in full or partial remission from MDD (rMDD; n=23) and age- and gender-matched healthy controls (HC; n=10). RSFC data were examined using seed-based connectivity of the left amygdala, left dorsolateral prefrontal cortex (dlPFC), and left posterior cingulate cortex (PCC). These seeds were chosen to probe the emotional salience, cognitive control, and default mode networks, respectively. Results: rMDD adolescents demonstrated relative hyperconnectivity from the left amygdala to the right PCC, as well as from the left dlPFC to the right middle frontal and left inferior frontal gyri (MFG, IFG). Amygdala to PCC connectivity was correlated with greater rumination, dlPFC to MFG connectivity was positively associated with depression severity, and dlPFC to IFG connectivity was inversely associated with mindfulness. Conclusions: Aberrant functional connectivity within and between neural networks responsible for salience attribution, introspective thought, and executive control can be observed among adolescents in the remitted phase of MDD and is associated with residual clinical symptoms. These patterns may confer risk for future relapse or alternatively, support wellness.