No abstract

Internet gaming disorder (IGD) is characterized by high levels of craving for online gaming and related cues. Since addiction-related cues can evoke increased activation in brain areas involved in motivational and reward processing and may engender gaming behaviors or trigger relapse, ameliorating cue-induced craving may be a promising target for interventions for IGD. This study compared neural activation between 40 IGD and 19 healthy control (HC) subjects during an Internet-gaming cue-reactivity task and found that IGD subjects showed stronger activation in multiple brain areas, including the dorsal striatum, brainstem, substantia nigra, and anterior cingulate cortex, but lower activation in the posterior insula. Furthermore, twenty-three IGD subjects (CBI + group) participated in a craving behavioral intervention (CBI) group therapy, whereas the remaining 17 IGD subjects (CBI − group) did not receive any intervention, and all IGD subjects were scanned during similar time intervals. The CBI + group showed decreased IGD severity and cue-induced craving, enhanced activation in the anterior insula and decreased insular connectivity with the lingual gyrus and precuneus after receiving CBI. These findings suggest that CBI is effective in reducing craving and severity in IGD, and it may exert its effects by altering insula activation and its connectivity with regions involved in visual processing and attention bias.

Studies conducted in drug addiction suggest a transition in processing of drug-related cues from the ventral to the dorsal component of the striatum. However, this process has not been studied in a behavioral addiction. Assessment of this process in a non-drug addiction can provide insight into the pathophysiology of both substance and behavioral addictions. Thirty-nine male IGD subjects and 23 male matched healthy controls (HCs) participated in functional magnetic resonance imaging (fMRI) during performance of a cue-reactivity task involving alternating presentation of Internet gaming-related stimuli (game cues) and general Internet surfing-related stimuli (control cues). Cue-induced neural activations in the ventral and dorsal striatum were compared between IGD and HC participants. Associations between cue-reactivity within these regions and cue-induced craving and severity and duration of IGD were also explored. IGD participants exhibited higher cue-induced activations within both the ventral and dorsal striatum (DS) when compared to HCs. Within the IGD group, activity within the left ventral striatum (VS) was correlated negatively with cue-induced craving; positive associations were found between activations within the DS (right putamen, pallidum and left caudate) and duration of IGD. Cue-induced activity within the left putamen was negatively associated with right VS volumes among IGD participants. Consistent with studies in substance addictions, our results suggest that a transition from ventral to dorsal striatal processing may occur among individuals with Internet gaming disorder, a condition without the impact of substance intake.

Internet gaming disorder (IGD) is characterized by cognitive and emotional deficits. Previous studies have reported the co-occurrence of IGD and depression. However, extant brain imaging research has largely focused on cognitive deficits in IGD. Few studies have addressed the comorbidity between IGD and depression symptoms and underlying neural mechanisms. Here, we systematically investigated this issue by combining a longitudinal survey study, a cross-sectional resting-state functional connectivity (rsFC) study and an intervention study. Autoregressive cross-lagged modeling on a longitudinal dataset of college students showed that IGD severity and depression are reciprocally predictive. At the neural level, individuals with IGD exhibited enhanced rsFC between the left amygdala and right dorsolateral prefrontal cortex (DLPFC), inferior frontal and precentral gyrus, compared with control participants, and the amygdala-frontoparietal connectivity at the baseline negatively predicted reduction in depression symptoms following a psychotherapy intervention. Further, following the intervention, individuals with IGD showed decreased connectivity between the left amygdala and left middle frontal and precentral gyrus, as compared with the non-intervention group. These findings together suggest that IGD may be closely associated with depression; aberrant rsFC between emotion and executive control networks may underlie depression and represent a therapeutic target in individuals with IGD.Registry name: The behavioral and brain mechanism of IGD;URL: https://www.clinicaltrials.gov/ct2/show/NCT02550405;Registration number: NCT02550405.

Decisional impulsivity represents an important phenotype and a therapeutic target in Internet gaming disorder (IGD). Reality therapy and mindfulness meditation were two approaches to reduce impulsivity. This study aimed to evaluate the efficacy of a group behavioral intervention combining reality therapy and mindfulness meditation in reducing decisional impulsivity and IGD severity. Twenty-five IGD and 21 healthy comparison (HC) young adults participated in baseline tests on the delay discounting and balloon analog risk tasks to measure intertemporal and risky decision-making respectively. Among them, 18 IGD subjects participated in the intervention and were tested again at the end of intervention, and 19 HC subjects without intervention were also tested twice within a similar time period. Results indicate that: (1) at baseline, IGD subjects showed greater intertemporal and risky decisional impulsivity than HC subjects; (2) After intervention, IGD subjects were decreased in delay discounting rate and IGD severity, but did not perform differently on decisional impulsivity in risky choices, as compared with baseline. These findings suggest that decisional impulsivity is a multifaceted behavioral construct and may serve as a possible therapeutic target for IGD. In addition, these results highlight the need for further research into the roles of different forms of decisional impulsivity in the shaping, maintenance, and remission of IGD.

Internet gaming disorder (IGD) has become a serious mental health issue worldwide. Evaluating the benefits of interventions for IGD is of great significance. Thirty-six young adults with IGD and 19 healthy comparison (HC) subjects were recruited and underwent resting-state fMRI scanning. Twenty IGD subjects participated in a group craving behavioral intervention (CBI) and were scanned before and after the intervention. The remaining 16 IGD subjects did not receive an intervention. The results showed that IGD subjects showed decreased amplitude of low fluctuation in the orbital frontal cortex and posterior cingulate cortex, and exhibited increased resting-state functional connectivity between the posterior cingulate cortex and dorsolateral prefrontal cortex, compared with HC subjects. Compared with IGD subjects who did not receive the intervention, those receiving CBI demonstrated significantly reduced resting-state functional connectivity between the: (1) orbital frontal cortex with hippocampus/parahippocampal gyrus; and, (2) posterior cingulate cortex with supplementary motor area, precentral gyrus, and postcentral gyrus. These findings suggest that IGD is associated with abnormal resting-state neural activity in reward-related, default mode and executive control networks. Thus, the CBI may exert effects by reducing interactions between regions within a reward-related network, and across the default mode and executive control networks.

Psychobehavioral intervention is an effective treatment of Internet addiction, including Internet gaming disorder (IGD). However, the neural mechanisms underlying its efficacy remain unclear. Cortical-ventral striatum (VS) circuitry is a common target of psychobehavioral interventions in drug addiction, and cortical-VS dysfunction has been reported in IGD; hence, the primary aim of the study was to investigate how the VS circuitry responds to psychobehavioral interventions in IGD. In a cross-sectional study, we examined resting-state functional connectivity of the VS in 74 IGD subjects (IGDs) and 41 healthy controls (HCs). In a follow-up craving behavioral intervention (CBI) study, of the 74 IGD subjects, 20 IGD subjects received CBI (CBI+) and 16 IGD subjects did not (CBI-). All participants were scanned twice with similar time interval to assess the effects of CBI. IGD subjects showed greater resting-state functional connectivity of the VS to left inferior parietal lobule (lIPL), right inferior frontal gyrus and left middle frontal gyrus, in positive association with the severity of IGD. Moreover, compared with CBI-, CBI+ showed significantly greater decrease in VS-lIPL connectivity, along with amelioration in addiction severity following the intervention. These findings demonstrated that functional connectivity between VS and lIPL, each presumably mediating gaming craving and attentional bias, may be a potential biomarker of the efficacy of psychobehavioral intervention. These results also suggested that non-invasive techniques such as transcranial magnetic or direct current stimulation targeting the VS-IPL circuitry may be used in the treatment of Internet gaming disorders.

These findings suggest that the deficient modulation of ECN versus DMN by SN might provide a mechanistic framework to better understand the neural basis of IGD and might provide novel evidence for the triple-network model in IGD.