Microstructure Abnormalities in Adolescents with Internet Addiction Disorder

TLDR

Internet addiction disorder has been linked to gray‑matter structural abnormalities, yet its impact on microstructural integrity of major neuronal fiber pathways and the relationship with addiction duration remain largely unexplored. This study aimed to elucidate the brain‑structural effects of internet addiction in adolescents. Eighteen adolescents with IAD underwent optimized voxel‑based morphometry and diffusion tensor imaging to assess gray‑matter volumes and white‑matter fractional anisotropy, with results correlated to addiction duration. We found widespread gray‑matter reductions in the dorsolateral prefrontal, supplementary motor, orbitofrontal cortices, cerebellum, and rostral ACC, along with increased FA in the left posterior limb of the internal capsule and decreased FA in the right parahippocampal gyrus, all of which correlated with longer internet‑addiction duration, indicating that chronic IAD induces structural brain alterations that may underlie persistent dysfunction.

Abstract

Background Recent studies suggest that internet addiction disorder (IAD) is associated with structural abnormalities in brain gray matter. However, few studies have investigated the effects of internet addiction on the microstructural integrity of major neuronal fiber pathways, and almost no studies have assessed the microstructural changes with the duration of internet addiction. Methodology/Principal Findings We investigated the morphology of the brain in adolescents with IAD (N = 18) using an optimized voxel-based morphometry (VBM) technique, and studied the white matter fractional anisotropy (FA) changes using the diffusion tensor imaging (DTI) method, linking these brain structural measures to the duration of IAD. We provided evidences demonstrating the multiple structural changes of the brain in IAD subjects. VBM results indicated the decreased gray matter volume in the bilateral dorsolateral prefrontal cortex (DLPFC), the supplementary motor area (SMA), the orbitofrontal cortex (OFC), the cerebellum and the left rostral ACC (rACC). DTI analysis revealed the enhanced FA value of the left posterior limb of the internal capsule (PLIC) and reduced FA value in the white matter within the right parahippocampal gyrus (PHG). Gray matter volumes of the DLPFC, rACC, SMA, and white matter FA changes of the PLIC were significantly correlated with the duration of internet addiction in the adolescents with IAD. Conclusions Our results suggested that long-term internet addiction would result in brain structural alterations, which probably contributed to chronic dysfunction in subjects with IAD. The current study may shed further light on the potential brain effects of IAD.