Alterations in functional connectivity in the salience network shared by depressive symptoms and smartphone overuse.

Globally, the age when children start using smartphones has decreased. Concurrently, the increased use of smartphones among children in developmental stages has caused serious effects, such as depression. While neuroimaging studies have predicted a significant overlap between the neurobiological changes caused by depression and smartphone overuse, few have simultaneously examined them. Therefore, we examined resting-state functional connectivity (FC) changes due to smartphone overuse and depressive symptoms in 69 children. We observed that FC in the salience network and regions involved in visual (e.g., the lateral occipital cortex) and motivational processing (e.g., the putamen) increased with smartphone overuse and depressive symptoms. Additionally, FC partially mediated the relationship between depressive symptoms and smartphone overuse, suggesting that changes in FC may be involved in the link between depressive symptoms and smartphone overuse. Our findings indicate that increased depressive symptoms could be associated with alterations in the salience network FC, which may influence visual attention or reward processing of salient stimuli, potentially contributing to smartphone overuse.