Ventral attention-network effective connectivity predicts individual differences in adolescent depression

Background: Stimulus-driven negative attention bias is a central deficit in depression and might play an important role in vulnerability to depression Adolescents are susceptible to depression. Thus, investigating the neural correlates of attention bias in adolescents is a critical step for identifying neural markers of early onset of depression. Previous studies have shown that the ventral attention network (VAN), which includes bilateral ventrolateral prefrontal cortex (VLPFC) and bilateral temporal-parietal junction (TPJ), is the key brain network for stimulus-driven attention. However, the relationship between depression and effective connectivity within the VAN in adolescents is poorly understood. Method: We employed resting-state fMRI to assess the relationship between directional effective connectivity within the VAN and depression scores in 216 healthy adolescents. Results: Using stochastic dynamic modeling, we found that individuals who exhibited higher self-reported depression showed stronger effective connectivity between right VLPFC and left TPJ within the VAN. Limitation: The level of depression in this study was assessed with self-reported questionnaire. This measure might be more influenced by current mood in adolescents than that in adults. Future studies should emplo more objective measures to index levels of depression. Conclusions: Our findings indicate that effective connectivity between right VLPFC and left TPJ could at least partially serve as a biomarker for bottom-up processing of depression in adolescents.