Interaction Between Tobacco Use Disorder And Internet Gaming Disorder Based On Resting-state Functional Magnetic Resonance Imaging

Addiction is a complex "biological-psycho-social-spiritual" disease,whose core feature is that addicts cannot control their addictive behaviors even though they know that it will bring various adverse consequences.It can be divided into substance use disorder and behavior addiction.Tobacco use disorder(TUD)and Internet Gaming disorder(IGD)are two typical forms of addiction.TUD is associated with cardiovascular and cerebrovascular diseases,respiratory diseases,cancer and other diseases,and is an important risk factor for cognitive decline and dementia.IGD was included in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders in 2013,and was officially considered as a mental disorder by the World Health Organization in 2019,attracting more and more attention from the public and researchers.Resting-state functional magnetic resonance imaging has been widely used in the study of TUD and IGD,and with which functional brain abnormalities has been found in functional activity,functional connectivity and functional networks between TUD individual and IGD patients.There are also few studies that have looked at both,such as studies that compared different changes in brain functional connectivity between IGD and TUD individual,or simply compare comorbidities with healthy controls,or compare two addictions with one addiction in only one aspect.Despite epidemiological studies of TUD and IGD comorbidities,such as TUD could predict high risk and the beginning of the IGD,no studies was found about interactions between TUD and IGD based on neuroimaging.So in order to better understand the neural mechanism of TUD and IGD interactions,it is urgent to study the interactions between TUD and IGD in neuroimaging.Based on the above background,this doctoral thesis recruited healthy control group,TUD group,IGD group,IGD and TUD comorbidity group(IGD-TUD)based on resting-state functional magnetic resonance imaging to study the interaction effects between TUD and IGD from three levels of functional activity,functional connection and functional network.The specific work is as follows:(1)At the functional activity level,amplitude low-frequency fluctuations(ALFF)was selected as the parameter of spontaneous brain functional activity to detect the brain regions with the interaction effects of TUD and IGD.The results showed that the brain regions with significant interaction effects were mainly located in the medial prefrontal cortex extending to the ventral striatum,left temporal gyrus,bilateral cerebellum and visual related regions.In these brain regions,it was found that the altered ALFF pattern between TUD and healthy groups was different from that between IGD-TUD and IGD groups,suggesting that the mechanism of TUD on the normal and IGD populations might be different.Similarly,it was also found that the altered ALFF pattern between IGD group and healthy control groups was different from that between IGD-TUD group and TUD group,suggesting that the mechanism of IGD on the healthy and TUD populations might be different.Combining the results of these two aspects,the interaction effects of TUD and IGD on spontaneous brain functional activity was verified.(2)At the functional connection level,ventral tegemental area(VTA),substantia nigra(SN),hippocampus and amygdala,which are closely related to addiction,were selected as seed points to calculate the functional connection between the seed points and the whole brain and analyze significant interaction effects between TUD and IGD.The significant interaction effects between TUD and IGD were found be in functional connection between the VTA,SN as well as hippocampus and the ventral striatum.In addition,significant functional connection interaction effects were also found between the rostral hippocampus and the sensorimotor area as well as the left middle temporal gyrus,between the medial amygdala and the right middle temporal gyrus,lingual gyrus,between the lateral amygdala and the medial orbitofrontal cortex/ventral striatum all had.Specifically,TUD had different effects on functional connectivity between healthy and IGD populations and IGD has different effects on functional connectivity between healthy and TUD populations.Therefore,the interaction effects between TUD and IGD was verified from the level of functional connectivity.(3)At the functional network level,the topological structure of the whole brain functional network,especially the modular structure,was studied by using graph theory method.The communication between modules was measured by participation coefficient.The results showed that although the brain functional networks of all four groups were "small-world" networks,their modular structures showed significant interaction effects between TUD and IGD,mainly located in the left posterior orbitofrontal cortex,right lateral orbitofrontal cortex,left superior marginal gyrus,middle temporal gyrus,inferior gyrus and angular gyrus.Similarly,it was found that TUD had different effects on healthy and IGD populations,and IGD had different effects on healthy and TUD populations.Therefore,the interaction between TUD and IGD was verified from the level of the functional brain network.In conclusion,resting-state functional magnetic resonance imaging was used to study the interaction effects between TUD and IGD from three levels:local brain functional activity,regional functional connectivity and global functional network.The results showed that the effects of TUD on the brain function of healthy and IGD populations were different,and the effects of IGD on the brain function of healthy and TUD populations were also different.That is,there were significant interaction effects between TUD and IGD on the brain function.These results provide reference value for understanding the neural mechanism of TUD and IGD alone or comorbidity,and also provide a new vision for the prevention and treatment of various addiction comorbidity.