Abstract
Aggression is a prevalent concern among adolescents with Internet Gaming Disorder (IGD), especially those with a history of childhood trauma. While IGD and childhood trauma are linked to aggression, the underlying neurobiological mechanisms remain poorly understood. This study aims to investigate how childhood trauma influences aggressive behaviour in adolescents with IGD through brain functional network alterations. A total of 108 adolescents with varying levels of IGD and childhood trauma were recruited and divided into IGD-with-trauma, IGD-without-trauma and healthy controls. Resting-state functional connectivity and graph theory analyses were used to investigate the global and nodal topological disruptions between groups. Then, correlation and mediation analyses were conducted to assess the relationship between functional network alterations, childhood trauma (Childhood Trauma Questionnaire-Short Form score) and aggression scores. Although all groups showed small-world topology in functional networks, compared to controls, both IGD groups exhibited significantly decreased normalized clustering coefficient (γ) and small-world index (σ). For regional topology, IGD with trauma group exhibited significantly reduced efficiency in bilateral superior parietal gyrus, left hippocampus, pallidum and thalamus compared with IGD without trauma group. Furthermore, γ, σ and nodal efficiency of left superior parietal gyrus not only showed significant correlations with Childhood Trauma Questionnaire-Short Form and Reactive Aggression scores, but also significantly mediated the correlation between Childhood Trauma Questionnaire and Reactive Aggression scores. These findings highlight both local brain dysfunctions and global topological disruptions contribute to aggressive behaviour, and provide valuable guidance for future intervention strategies that improving the integration and efficiency of brain functional networks may help reduce aggression in at-risk youths with IGD and trauma histories.