Magnetic Resonance Imaging Study Of Abnormal Midbrain Pathway In Adolescents With Internet Gaming Disorder

Internet gaming disorder(IGD)is a serious and growing public health problem.Growing evidence has demonstrated that functional and structural abnormalities in individuals with IGD similar to other type of addiction,which is an adequate basis for the addictive properties.Dopamine projections from the ventral tegmental area(VTA)to the striatum especially the nucleus accumbens(NAc)and the prefrontal cortex are implicated in reward processing,motivation and cognitive control.However,there is limited knowledge on the involvement of structural of functional disruption within the midbrain dopamine nuclei centered circuits in IGD.In the first study,we examined the alteration of resting state functional connectivity(RSFC)and diffusion tensor imaging based structural connectivity VTA circuits.Correlation analysis was carried out to investigate the relationship between the neuroimaging findings and the behavioral Internet Addiction Test(IAT).Bothe the NAc and the medial orbitofrontal cortex(m OFC)showed lower RSFC with VTA in IGD subjects compared with controls.The IGD also showed lower structural connectivity in bilateral VTA-NAc tracts compared with controls.Moreover,the RSFC strength of VTA-right NAc and VTA-left m OFC correlated negatively with IAT in IGD.We provide evidence that functional and structural connectivity of the VTA pathways are implicated in IGD.Since theses pathways are important for dopamine reward signals and salience attribution,the findings suggest involvement of the brain reward system in the neurobiology of IGD.These results strengthen the evidence that IGD share similar neuropathology with other addiction.Although growing evidence has confirmed the neurological mechanism abnormality in IGD,it is still an active debate as to whether IGD is a brain disorder.One reason is the uncertainty clinical diagnosis.Many international organizations have put forward the diagnostic criteria of IGD,but there are many subjective deviations in the application,which lead to some defects.To further explore the abnormal changes of distributed multidimensional effect of VTA circuits and study individual models that can be used to clinical diagnosis,the multivoxel pattern analysis(MVPA)was carried out for evaluating this hypothesis.We applied this method with functional connectivity features to classify IGD and control subjects.The results showed that the most discriminative features were bilateral thalamus,bilateral hippocampus,right pallidum,right parahippocampal,and superior temporal gyrus and accuracy of 86.9% was achieved.Furthermore,some functional connectivity features were negatively correlated with IAT in IGD.These findings provided direct evidence supporting a multidimensional effect of the VTA circuits in IGD.Finally,the discriminative power demonstrates the potential of VTA neuroimaging features in identifying IGD.In summary,this paper reveals the abnormal regulation patterns of the VTA pathways in IGD.This abnormal pattern change is not only correlated with the IAT,but also can be used to identify individuals with IGD.These results confirms that IGD have similar neurological with substance use disorder.We hope that our study can provide an important theoretical basis for the study of the neural mechanism and prediction of IGD.