Abnormal Brain Structure in Teens with Internet Addiction

Microstructure Abnormalities in Adolescents with Internet Addiction Disorder

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.
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.
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.

Kai Yuan¹, Wei Qin¹, Guihong Wang^1,2, Fang Zeng³, Liyan Zhao⁴, Xuejuan Yang¹, Peng Liu¹, Jixin Liu¹, Jinbo Sun¹, Karen M. von Deneen¹, Qiyong Gong⁵, Yijun Liu^6*, Jie Tian^1,7*

1 School of Life Sciences and Technology, Life Sciences Research Center, Xidian University, Xi'an, Shaanxi, China, 2 Department of Applied Mathematics, Xidian University, Xi'an, Shaanxi, China, 3 The 3rd Teaching Hospital, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China, 4 National Institute on Drug Dependence, Peking University, Beijing, China, 5 Department of Radiology, The Center for Medical Imaging, Huaxi MR Research Center (HMRRC), West China Hospital of Sichuan University, Chengdu, Sichuan, China, 6 Departments of Psychiatry and Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America, 7 Institute of Automation, Chinese Academy of Sciences, Beijing, China

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.

Citation: Yuan K, Qin W, Wang G, Zeng F, Zhao L, et al. (2011) Microstructure Abnormalities in Adolescents with Internet Addiction Disorder. PLoS ONE 6(6): e20708. doi:10.1371/journal.pone.0020708
Editor: Shaolin Yang, University of Illinois at Chicago, United States of America
Received: December 16, 2010; Accepted: May 10, 2011; Published: June 3, 2011
Copyright: © 2011 Yuan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This paper is supported by CAS Hundred Talents Program, the National Natural Science Foundation of China under grant nos. 30970774, 60901064, 30873462, 30870685, 81000641, 81000640, 81071217, 31028010, 81071137, the Project for the National Key Basic Research and Development Program (973) under grant nos. 2011CB707700, 2011CB707702, and 863 program under grant no. 2008AA01Z411, the Fundamental Research Funds for the Central Universities. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: yijunliu@ufl.edu (YL); tian@ieee.org (JT)