Cognitive Control as a Brake on the Depression–Internet Addiction Link: Task-Based fMRI Evidence from Activation and Task-Modulated Functional Connectivity

Internet addiction is closely associated with negative emotions such as depression, and cognitive control has been proposed to moderate this relationship. However, the underlying neural mechanisms remain unclear. Using a publicly available fMRI dataset, this study examined whether cognitive control-related brain activation and task-modulated functional connectivity (TMFC) moderate the association between depressive symptoms and Internet addiction. Thirty-four participants completed a global–local attention allocation task during fMRI, the Internet Addiction Test (IAT), and Beck Depression Inventory (BDI). Behaviorally, accuracy under conflict conditions negatively moderated the BDI–IAT association. At the neural level, activation in the left dorsolateral prefrontal cortex and left ventromedial prefrontal cortex negatively moderated this association, whereas activation in the right substantia nigra, right nucleus accumbens, and right caudate nucleus positively moderated it. At the network level, stronger functional connectivity between the frontoparietal control network and the subcortical network weakened the positive BDI–IAT association. These findings suggest that prefrontal regions and frontoparietal–subcortical connectivity may buffer the depression–Internet addiction link, whereas subcortical reward- and habit-related regions may amplify it, providing neuroimaging support for the I-PACE model.