E-Mail karger@karger.com Research Report Eur Addict Res 2016;22:192–200 DOI: 10.1159/000440716 Altered Functional Connectivity of the Insula and Nucleus Accumbens in Internet Gaming Disorder: A Resting State fMRI Study Chiao-Yun Chen   a, c Ju-Yu Yen   b, d, e Peng-Wei Wang   b, d Gin-Chung Liu   a, c Cheng-Fang Yen   b, d Chih-Hung Ko   b, d, f a  Department of Medical Imaging, b  Department of Psychiatry, Kaohsiung Medical University Hospital, c  Department of Radiology, d  Department of Psychiatry, Faculty of Medicine, College of Medicine, e  Department of Psychiatry, Kaohsiung Municipal Ta-Tung Hospital, and f  Department of Psychiatry, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan and might explain why it is involved in IGD. The attenuated frontostriatal suggests that the emotion-driven gaming urge through nucleus accumbens could not be well regu- lated by the frontal lobe of subjects with IGD. © 2016 S. Karger AG, Basel Introduction Internet Gaming Disorder The Internet is a facility that is available 24 hours a day; a loss of control of Internet use may result in nega- tive psychosocial consequences [1]. The dys-control In- ternet use is labeled as Internet addiction [2]. Internet gaming disorder (IGD) is one of the more popular sub- types (57.5%) of Internet addiction [3]. As for its sig- nificant public importance, the DSM 5 recruited IGD in Section III [4] and suggested that adequate evidence was necessary to support it as an independent disorder. Sub- jects with IGD have been reported to play online gaming for 5.87 h/day on weekdays and 8.51 h/day at weekends [5]. The long-term gaming experience might make a dif- ference in brain function [6]. On the other hand, the al- teration in brain functioning might represent character- istics such as impulsivity [7] that could predict IGD. Key Words Internet gaming disorder · Functional connectivity · Insula · Nucleus accumbens · Frontal lobe · Impulsivity Abstract Aims: A possible addiction mechanism has been represent- ed by altered functional connectivity (FC) in the resting state. The aim of this study was to evaluate the FCs of the insula and nucleus accumbens among subjects with Internet gam- ing disorder (IGD). Methods: We recruited 30 males with IGD and 30 controls and evaluated their FC using functional magnetic imaging scanning under resting, a state with relax- ation, closed eyes, with inducement to think of nothing sys- tematically, become motionless, and instructed not to fall asleep. Results: Subjects with IGD had a lower FC with the left insula over the left dorsolateral prefrontal cortex (DLPFC) and orbital frontal lobe and a higher FC with the insula with the contralateral insula than controls. The inter-hemispheric insula connectivity positively correlated with impulsivity. Further, they had lower FC with the left nucleus accumbens over the left DLPFC and with the right nucleus accumbens over the left DLPFC, and insula and a higher FC with that over the right precuneus. Conclusion: The elevated inter-hemi- spheric insula FC is found to be associated with impulsivity Received: February 24, 2015 Accepted: August 28, 2015 Published online: February 11, 2016 E u r o pea n Addi cti o n c R e e s ar h Chih-Hung Ko Department of Psychiatry Faculty of Medicine, College of Medicine, Kaohsiung Medical University 100 Tzyou 1st Rd. Kaohsiung City 807 (Taiwan) E-Mail cyberko  @  seed.net.tw © 2016 S. Karger AG, Basel 1022–6877/16/0224–0192$39.50/0 www.karger.com/ear