| Background: In the past two decades,the pathological use of games has become a clinically serious public health problem.The fifth edition of the "Diagnostic and Statistical Manual of Mental Disorders"(DSM-5)in 2013 included "Internet Gaming Disorder"(IGD)in the third part as a type requiring further verification.However,it is controversial whether IGD can be classified as an independent psychiatric condition or an ” addiction and related disorders”.One of the difficulties is the lack of longitudinal data to examine their natural development.The causal relationship between the potential neurobiological characteristics of game addicts and their pathological game behaviors remains to be determined.Studies have shown that the functional heterogeneity of the striatum of people with addictive behaviors may involve the transition from ventral to dorsal partitions.However,due to the limitations of cross-sectional design,it is not clear whether the contribution of this transition to addiction is confused by individual differences,especially for individuals with IGD.Therefore,it is of great significance to explore the longitudinal data of online game addiction.Methods: Longitudinal f MRI data from 40 subjects(22 IGD(mean age: 20.4 ± 2.0years)and 18 healthy controls(mean age: 20.2 ± 1.9 years))were collected in current study.Subjects were reassessed ≥6 months after the initial scanning(mean interval: 9.3 ± 3.5months),We examined the connectivity features of sub regions within the striatum between these two scans.Based on the results,question two we further established a dynamic causal model to explore the directional effects between regions,and in question three,these key features are used in machine learning data classification to test the repeatability of the results.Results: Comparing with controls,IGD subjects exhibited decreased functional connectivity between the left dorsal striatum(putamen)and the left insula,whereas connectivity between the right ventral striatum(nucleus accumbens,Nacc)and the left insula was relatively stable over time.An inhibitory effective connectivity from the left putamen to the right Nacc was found in IGD subjects during the follow-up scan.Using the above characteristics,the classification accuracy of the training model developed later is better than that of the training model based on the initial scan.Conclusions: Persistent IGD status was accompanied by a switch of areaof control within the striatum.This provides new insights into whether IGD can be considered an independent mental disorder. |
