White matter integrity of right frontostriatal circuit predicts internet addiction severity among internet gamers.

Excessive use of the internet, which is a typical scenario of self-control failure, could lead to potential consequences such as anxiety, depression, and diminished academic performance. However, the underlying neuropsychological mechanisms remain poorly understood. This study aims to investigate the structural basis of self-control and internet addiction. In a cohort of 96 internet gamers, we examined the relationships among grey matter volume and white matter integrity within the frontostriatal circuits and internet addiction severity, as well as self-control measures. The results showed a significant and negative correlation between dACC grey matter volume and internet addiction severity (p < 0.001), but not with self-control. Subsequent tractography from the dACC to the bilateral ventral striatum (VS) was conducted. The fractional anisotropy (FA) and radial diffusivity of dACC-right VS pathway was negatively (p = 0.011) and positively (p = 0.020) correlated with internet addiction severity, respectively, and the FA was also positively correlated with self-control (p = 0.036). These associations were not observed for the dACC-left VS pathway. Further mediation analysis demonstrated a significant complete mediation effect of self-control on the relationship between FA of the dACC-right VS pathway and internet addiction severity. Our findings suggest that the dACC-right VS pathway is a critical neural substrate for both internet addiction and self-control. Deficits in this pathway may lead to impaired self-regulation over internet usage, exacerbating the severity of internet addiction.

Comparative efficacy of different interventions on executive function in adolescents with internet use disorder.

BACKGROUND: The formation and relapse of Internet use disorder (IUD) are related to the decline in executive function. Previous studies have indicated that exercise intervention and high-definition transcranial direct current stimulation (HD-tDCS) can improve the cognitive abilities of adolescents with IUD. However, the combined intervention's impact on executive function in these adolescents remains unclear. Therefore, this study aims to explore the effects and differences of multimodal exercise, HD-tDCS intervention, and combined intervention on the executive function of adolescents with IUD. METHODS: Forty-eight adolescents with IUD were randomly assigned to the multimodal exercise group, HD-tDCS intervention group, combined intervention group, and control group. The intervention groups received 4 weeks of moderate-intensity multimodal exercise, HD-tDCS intervention (2 mA, 20min/session, 3 times/week), or combined multimodal exercise with HD-tDCS intervention. The control group received conventional educational learning. Executive function measurements were taken before intervention, after intervention, and 2 weeks post-intervention. RESULTS: Compared to pre-intervention, different interventions effectively improved the behavioral performance of adolescents with IUD in executive function tasks. In comparison to single interventions, the combined intervention significantly outperformed multimodal exercise and HD-tDCS intervention in influencing the executive function (especially inhibitory control and working memory) in adolescents with IUD. CONCLUSION: Combined multimodal exercise with HD-tDCS intervention proves to be an effective means of enhancing executive function in adolescents with IUD, particularly contributing to the improvement of explicit behavioral performance related to executive function.

Brain responses to decision-making in easy and hard choices in internet gaming disorder: Implications for irrepressible gaming behaviours.

BACKGROUND: Impaired decision-making was observed in internet gaming disorder (IGD), however, these studies did not differentiate 'hard' to 'easy' decisions, and only the 'hard' decision-making could reveal the mechanism underlying this issue. METHODS: We recruited forty-eight individuals with IGD and forty-six recreational internet game users (RGUs) as a control group in this study. fMRI data were collected when they were finishing a value-matching delayed discount task (DDT), which included easy and hard decisions judging based on the indifference points of every participant. The correlations between brain responses during DDT and IGD severity and the effective connectivity between brain regions were calculated. RESULTS: Compared to RGUs, IGD subjects showed enhanced activation in the orbitofrontal cortex (OFC) when facing hard choices, and this feature was associated with IGD severity. In addition, individuals with IGD showed increased effective connectivity from the OFC to the dorsolateral prefrontal cortex and the OFC to the occipital lobe and decreased effective connectivity from the occipital lobe to the OFC. CONCLUSION: The current study showed that the abnormal activation in the OFC was associated with IGD severity and higher OFC-DLPFC/OFC-occipital lobe effective connectivity and lower occipital lobe-OFC effective connectivity when individuals with IGD faced different choices in the DDT. These findings suggest the neural mechanisms of impulsive decision-making in individuals with IGD due to dysfunction with subjective evaluation and dysfunction of the connection with the executive control system.

Can internet use become addictive?

Problematic internet use parallels drug addiction, but the mechanisms are not yet clear.

Brain functional connectivity during and after imagery of gaming and alternative leisure activities in patients with internet gaming disorder.

BACKGROUND: The effect of gaming cue exposure on brain activity in patients with internet gaming disorder (IGD) has been investigated a lot, but the effect on brain connectivity has not. This study aimed to investigate the effects of imageries of gaming and alternative leisure activities on functional connectivity during the during-task and post-task states in patients with IGD. METHODS: Twenty-nine patients and 20 healthy controls were scanned in the 6-min states before, during, and after the imagery tasks for gaming and alternative leisure behaviors using fMRI. Seed-based functional connectivity during and after the tasks were analyzed. The seeds were the nucleus accumbens (NAcc), ventral tegmental area (VTA), caudate, putamen, anterior cingulate cortex (ACC), and posterior cingulate cortex. RESULTS: The group-by-state interaction effects for the during-tasks were found in caudate-, putamen-, and ACC-based connectivity, whereas those for the post-tasks were shown only in NAcc-based connectivity. In particular, patients showed that caudate-right parahippocampal gyrus connectivity and putamen-right orbitofrontal cortex connectivity increased during gaming and decreased during alternative, whereas NAcc-right precuneus connectivity decreased at baseline, increased in post-gaming, and were not different in post-alternative. CONCLUSION: Differences in during-task connectivity of the habit/motor and salience networks and post-task resting-state connectivity of the reward and limbic networks between the two imagery tasks may differ between the groups. In the treatment of IGD, when these network connections are reactive to alternative leisure activity, just as to gaming activity, they seem to be freed from gaming addiction.

Resting-state functional connectivity within orbitofrontal cortex and inferior frontal gyrus modulates the relationship between reflection level and risk-taking behavior in internet gaming disorder.

Internet gaming disorder (IGD) has become an increasing mental health issue worldwide. Previous studies indicated that IGD was related to maladaptive risk-taking behavior. However, the relationship among risk-taking behavior, reflection level, and resting-state functional connectivity (rsFC) between brain regions in IGD individuals remains unclear. The current study combined resting-state fMRI and the Devil task to investigate this issue. The behavioral results suggested that IGD participants exhibited increased risk-taking behavior in the Devil task than healthy controls. Moreover, IGD participants' risk-taking behavior was positively correlated with their reflection level. As for fMRI results, IGD participants showed stronger rsFC between orbitofrontal cortex (OFC) and inferior frontal gyrus (IFG) than healthy controls. Additionally, the mediation analyses revealed that, among IGD participants, the rsFC between OFC and IFG fully mediated the relationship between reflection level and risk-taking behavior. Together, the current study highlighted that the altered rsFC between OFC and IFG in IGD individuals modified the relationship between their reflection level and risk-taking behavior, which might contribute to the understanding of neural mechanisms underlying risk-taking behavior in IGD individuals.

Connectome-based prediction of craving for gaming in internet gaming disorder.

BACKGROUND: Craving-related brain responses have been associated with the emergence and maintenance of addictions. However, little is known about brain network organizations underlying cravings in internet gaming disorder (IGD). METHODS: Sixty-six IGD subjects and 61 matched individuals with recreational game use (RGU) were scanned while performing a cue-craving task. A recently developed whole-brain analysis approach, connectome-based predictive modelling (CPM) with leave-one-out cross-validation was conducted to identify networks that predicted craving responses in IGD. Then, the craving network was tested in different brain states (cue-craving under deprivation) to investigate replicability. RESULTS: CPM identified an IGD craving network, as indicated by a significant correspondence between predicted and actual craving values (r = 0.49, p < 0.001), characterized by within-network default mode (DMN) connectivity and connectivity between canonical networks implicated in executive/cognitive control (frontoparietal, medial frontal, DMN) and reward responsiveness (subcortical, motor/sensory). Network strength in the cue-craving task during gaming deprivation also predicted IGD craving scores (r = 0.43, p = 0.017), indicating network replication across brain states. CONCLUSIONS: The CPM results demonstrate that individual differences in cognitive, attention, and control network function can predict craving intensities in IGD subjects. These networks may be targets for potential interventions using brain modulation.

Addiction Research Unit: Affective and cognitive mechanisms of specific Internet-use disorders.

In the eleventh International Classification of Diseases (ICD-11) of the World Health Organization, gambling disorder and gaming disorder are included in the category 'disorders due to addictive behaviours', which can be specified further as occurring either predominantly offline or predominantly online. Other specific problematic behaviours may be considered for the category 'other specified disorders due to addictive behaviours'. The Research Unit FOR 2974, funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG), focuses on the most prominent online addictive behaviours: gaming, pornography use, buying-shopping and social-networks use. The main goal of the Research Unit is to contribute to a better understanding of the common and differential psychological as well as neurobiological mechanisms involved in these specific types of Internet-use disorders. We aim to investigate theoretically argued (bio)psychological processes with a focus on concepts coming from research of substance-use disorders, for example, cue reactivity and craving, executive functions and specific inhibitory control, coping, implicit cognitions, and decision making. One central characteristic of the Research Unit is that we will investigate all participants using a comprehensive core battery of experimental paradigms, neuropsychological tasks, questionnaires, biomarkers, ambulatory assessment, and a 6-month follow-up survey. Beyond the anticipated contributions to the scientific understanding of the mechanisms involved in the development and maintenance of respective online addictive behaviours, we also expect contributions to clinical practice by showing which affective and cognitive mechanisms may be addressed more intensively to optimize treatment.

Attached to Virtual Dreams: The Mediating Role of Maladaptive Daydreaming in the Relationship Between Attachment Styles and Problematic Social Media Use.

ABSTRACT: Maladaptive daydreaming describes excessive fantasy activity that interferes with an individual's life. Surprisingly, the precursors of maladaptive daydreaming and its role in excessive involvement in virtual worlds have been scarcely investigated. In the current study, we examined the relationships among attachment styles, maladaptive daydreaming, and problematic social media use (PSMU) in a sample of community-dwelling adults. Eight hundred seventy-seven participants between 18 and 68 years old were recruited via an online survey and asked to fill out self-reported measures on attachment styles, maladaptive daydreaming, and PSMU. Mediation analyses showed that maladaptive daydreaming is a significant mediator in the relationships between preoccupied and fearful attachment styles and PSMU, suggesting that maladaptive daydreaming partly explains the established link between insecure attachment styles and excessive use of social media. Individuals with PSMU fostered by maladaptive daydreaming may benefit from clinical interventions that promote the use of adaptive regulatory strategies to develop feelings of security and self-confidence that may serve to reduce the excessive involvement in social media.

Dorsal and ventral striatal functional connectivity shifts play a potential role in internet gaming disorder.

Animal models suggest transitions from non-addictive to addictive behavioral engagement are associated with ventral-to-dorsal striatal shifts. However, few studies have examined such features in humans, especially in internet gaming disorder (IGD), a proposed behavioral addiction. We recruited 418 subjects (174 with IGD; 244 with recreational game use (RGU)). Resting-state fMRI data were collected and functional connectivity analyses were performed based on ventral and dorsal striatal seeds. Correlations and follow-up spectrum dynamic causal model (spDCM) analyses were performed to examine relationships between the ventral/dorsal striatum and middle frontal gyrus (MFG). Longitudinal data were also analysed to investigate changes over time. IGD relative to RGU subjects showed lower ventral-striatum-to-MFG (mostly involving supplementary motor area (SMA)) and higher dorsal-striatum-to-MFG functional connectivity. spDCM revealed that left dorsal-striatum-to-MFG connectivity was correlated with IGD severity. Longitudinal data within IGD and RGU groups found greater dorsal striatal connectivity with the MFG in IGD versus RGU subjects. These findings suggest similar ventral-to-dorsal striatal shifts may operate in IGD and traditional addictions.

Age-related and individual variations in altered prefrontal and cerebellar connectivity associated with the tendency of developing internet addiction.

Internet addiction refers to problematic patterns of internet use that continually alter the neural organization and brain networks that control impulsive behaviors and inhibitory functions. Individuals with elevated tendencies to develop internet addiction represent the transition between healthy and clinical conditions and may progress to behavioral addictive disorders. In this network neuroscience study, we used resting-state functional magnetic resonance imaging (rs-fMRI) to examine how and whether individual variations in the tendency of developing internet addiction rewire functional connectivity and diminish the amplitude of spontaneous low-frequency fluctuations in healthy brains. The influence of neurocognitive aging (aged over 60 years) on executive-cerebellar networks responsible for internet addictive behavior was also investigated. Our results revealed that individuals with an elevated tendency of developing internet addiction had disrupted executive-cerebellar networks but increased occipital-putamen connectivity, probably resulting from addiction-sensitive cognitive control processes and bottom-up sensory plasticity. Neurocognitive aging alleviated the effects of reduced mechanisms of prefrontal and cerebellar connectivity, suggesting age-related modulation of addiction-associated brain networks in response to compulsive internet use. Our findings highlight age-related and individual differences in altered functional connectivity and the brain networks of individuals at a high risk of developing internet addictive disorders. These results offer novel network-based preclinical markers of internet addictive behaviors for individuals of different ages.

Sex difference in neural responses to gaming cues in Internet gaming disorder: Implications for why males are more vulnerable to cue-induced cravings than females.

BACKGROUND: Although drug addiction studies have shown that females are more likely to become addicted and sensitive to drug cues, this feature seems reversed in Internet gaming disorder (IGD), of which males are more likely to be sufferers. Given the prevalence of IGD in the male population, the current study was set to examine the potential effect of sex on IGD's craving using a cue reactivity task. METHODS: Sixty-five (32 males) IGD subjects underwent fMRI scanning during exposure to visual gaming cues and neutral cues. Brain responses to gaming cues relative to neutral cues were examined within two groups separately. In addition, Granger causal analysis (GCA) was conducted to investigate how the effective connectivity patterns were altered in male and female IGD subjects. RESULTS: When facing gaming cues, lower regions of brain activation were observed in males compared to females, including the left anterior cingulate cortex (ACC), the superior frontal gyrus and the posterior cingulate cortex (PCC); GCA results, using the PCC as the ROI, showed higher middle temporal gyrus-PCC-right ACC/parahippocampal gyrus effective connectivity in males as compared with females, when exposed to gaming cues. CONCLUSION: The results indicate that gaming cues could more severely disturb male IGD subjects' inhibition control function over game-elicited cravings compared to females, which might make it hard for males to control their game cravings and stop their gaming behaviors. This conclusion is valuable in understanding why males are more vulnerable to IGD than females.

Electroencephalography-detected neurophysiology of internet addiction disorder and internet gaming disorder in adolescents - A review.

INTRODUCTION: Internet Addiction Disorder (IAD) is an umbrella term for various types of Internet-based behavioural addiction, whereas Internet Gaming Disorder (IGD) addresses a specific type of IAD that is postulated to be due to a lack of control in impulse inhibition. IGD is an area of concern in the Diagnostic and Statistics Manual of Mental Disorders (DSM-5), which can be objectively assessed by dysfunctional behaviour and the increasing time of being online, particularly during the COVID-19 pandemic. Electroencephalography (EEG) identifies amplitude changes in the evoked response potential (ERP) among IGDs, correlated with underlying comorbidities. MATERIALS AND METHODS: A scoping review was performed to elaborate on the research regarding resting-state EEG and task-based EEG, particularly for Go/No-go paradigms pertaining to subjects with IAD or specifically IGD. The role of EEG was identified in its diagnostic capability to identify the salient changes that occurred in the response to reward network and the executive control network, using restingstate and task-based EEG. The implication of using EEG in monitoring the therapy for IAD and IGD was also reviewed. RESULTS: EEG generally revealed reduced beta waves and increased theta waves in addicts. IGD with depression demonstrated increased theta and decreased alpha waves. Whereas increased P300, a late cognitive ERP component, was frequently associated with impaired excessive allocation of attentional resources of the IAD towards addiction-specific cues. IGD had increased whole brain delta waves at baseline, which showed significant reduction post therapy. CONCLUSION: EEG can identify distinct neurophysiological changes among Internet Addiction Disorder and Internet Gaming Disorder that are akin to substance abuse disorders.

Viewing personalized video clips recommended by TikTok activates default mode network and ventral tegmental area.

Cutting-edge recommendation algorithms have been widely used by media platforms to suggest users with personalized content. While such user-specific recommendations may satisfy users' needs to obtain intended information, some users may develop a problematic use pattern manifested by addiction-like undesired behaviors. Using a popular video sharing and recommending platform (TikTok) as an example, the present study first characterized use-related undesired behaviors with a questionnaire, then investigated how personally recommended videos modulated brain activity with an fMRI experiment. We found more undesired symptoms were related to lower self-control ability among young adults, and about 5.9% of TikTok users may have significant problematic use. The fMRI results showed higher brain activations in sub-components of the default mode network (DMN), ventral tegmental area, and discrete regions including lateral prefrontal, anterior thalamus, and cerebellum when viewing personalized videos in contrast to non-personalized ones. Psychophysiological interaction analyses revealed stronger coupling between activated DMN subregions and neural pathways underlying auditory and visual processing, as well as the frontoparietal network. This study highlights the functional heterogeneity of DMN in viewing personalized videos and may shed light on the neural underpinnings of how recommendation algorithms are able to keep the user's attention to suggested contents.

Altered functional network activities for behavioral adjustments and Bayesian learning in young men with Internet gaming disorder.

BACKGROUND AND AIMS: Deficits in cognitive control represent a core feature of addiction. Internet Gaming Disorder (IGD) offers an ideal model to study the mechanisms underlying cognitive control deficits in addiction, eliminating the confounding effects of substance use. Studies have reported behavioral and neural deficits in reactive control in IGD, but it remains unclear whether individuals with IGD are compromised in proactive control or behavioral adjustment by learning from the changing contexts. METHODS: Here, fMRI data of 21 male young adults with IGD and 21 matched healthy controls (HC) were collected during a stop-signal task. We employed group independent component analysis to investigate group differences in temporally coherent, large-scale functional network activities during post-error slowing, the typical type of behavioral adjustments. We also employed a Bayesian belief model to quantify the trial-by-trial learning of the likelihood of stop signal - P(Stop) - a broader process underlying behavioral adjustment, and identified the alterations in functional network responses to P(Stop). RESULTS: The results showed diminished engagement of the fronto-parietal network during post-error slowing, and weaker activity in the ventral attention and anterior default mode network in response to P(Stop) in IGD relative to HC. DISCUSSION AND CONCLUSIONS: These results add to the literatures by suggesting deficits in updating and anticipating conflicts as well as in behavioral adjustment according to contextual information in individuals with IGD.

Gender-related differences in frontal-parietal modular segregation and altered effective connectivity in internet gaming disorder.

BACKGROUND: Although previous studies have revealed gender-related differences in executive function in internet gaming disorder (IGD), neural mechanisms underlying these processes remain unclear, especially in terms of brain networks. METHODS: Resting-state fMRI data were collected from 78 subjects with IGD (39 males, 20.8 ± 2.16 years old) and 72 with recreational game use (RGU) (39 males, 21.5 ± 2.56 years old). By utilizing graph theory, we calculated participation coefficients among brain network modules for all participants and analyzed the diagnostic-group-by-gender interactions. We further explored possible causal relationships between networks through spectral dynamic causal modeling (spDCM) to assess differences in between-network connections. RESULTS: Compared to males with RGU, males with IGD demonstrated reduced modular segregation of the frontal-parietal network (FPN). Male IGD subjects also showed increased connections between the FPN and cingulo-opercular network (CON); however, these differences were not found in female subjects. Further spDCM analysis indicated that the causal influence from CON to FPN in male IGD subjects was enhanced relative to that of RGU males, while this influence was relatively reduced in females with IGD. CONCLUSIONS: These results suggest poor modular segmentation of the FPN and abnormal FPN/CON connections in males with IGD, suggesting a mechanism for male vulnerability to IGD. An increased "bottom-up" effect from the CON to FPN in male IGD subjects could reflect dysfunction between the brain networks. Different mechanisms may underlie in IGD, suggesting that different interventions may be optimal in males and females with IGD.

The relationships between negative emotions and latent classes of smartphone addiction.

The relationships between negative emotions and smartphone addiction has been tested through the literature. However, most of the studies applied variable-centered approaches. The heterogeneity of smartphone addiction severity has not been examined for the associations with negative emotion variables. The purposes of the present study is to explore the latent classes of smartphone addiction and analyze the relationships between depression, social anxiety and boredom and these subgroups. The Smartphone Addiction Scale-Short Version (SAS-SV) and three negative emotion scales were employed to conduct a survey of 539 college students. Mplus8.3 software was applied to perform the latent class analysis (LCA) based on the smartphone addiction symptom ratings. ANOVA and multinomial logistic regression were used to explore the differences among these latent categories and the associations between these subgroups and negative emotion variables. Results demonstrated that Negative emotional variables were significantly correlated with smartphone addiction proneness. Based on their scores on the Smartphone Addiction Scale, smartphone users were divided into three latent classes: low risk class, moderate class and high risk class. Women were more likely to be classified in the high-risk class. The severity of depression and boredom was able to predict the membership of the latent class effectively; while social anxiety failed to do this in the high risk class.

Differences in resting-state functional connectivity according to the level of impulsiveness in patients with internet gaming disorder.

BACKGROUND AND AIMS: Impulsiveness is an important factor in the pathophysiology of Internet gaming disorder (IGD), and regional brain functions can be different depending on the level of impulsiveness. This study aimed to demonstrate that different brain mechanisms are involved depending on the level of impulsiveness among patients with IGD. METHODS: Resting-state functional MRI data were obtained from 23 IGD patients with high impulsivity, 27 IGD patients with low impulsivity, and 22 healthy controls, and seed-based functional connectivity was compared among the three groups. The seed regions were the ventromedial prefrontal cortex (vmPFC), dorsolateral prefrontal cortex, nucleus accumbens (NAcc), and amygdala. RESULTS: Connectivity of the vmPFC with the left temporo-parietal junction (TPJ) and NAcc-left insula connectivity were significantly decreased in the patients with high impulsivity, compared with the patients with low impulsivity and healthy controls. On the other hand, amygdala-based connectivity with the left inferior frontal gyrus showed decreases in both patient groups, compared with the healthy controls. CONCLUSION: These findings may suggest a potential relationship between impulsivity and deficits in reward-related social cognition processes in patients with IGD. In particular, certain interventions targeted at vmPFC-TPJ connectivity, found to be impulsivity-specific brain connectivity, are likely to help with addiction recovery among impulsive patients with IGD.

A systematic review and meta-analysis on the clinical implications of probability discounting among individuals with Internet gaming disorder.

The significance of probability discounting (PD) among individuals with Internet gaming disorder (IGD) remains unclear. Following the PRISMA guidelines, we systematically searched the PubMed, Embase, and ScienceDirect databases for English articles on Internet addiction that included comparison between individuals with and without IGD as well as probabilistic discounting task as the main outcome from January 1970 to July 2020 using the appropriate keyword strings. The primary outcome was the overall difference in rate of PD, while the secondary outcomes included the difference in PD with magnitude of probabilistic reward and response time of the PD task. Effect size (ES) was calculated through dividing the group means (e.g., h value or AUC) by the pooled standard deviations of the two groups. A total of five studies with 300 participants (i.e., IGD group, n = 150, mean age = 20.27 ± 2.68; healthy controls, n = 150, mean age = 20.70 ± 2.81) were analyzed. The IGD group was more willing to take risks in probabilistic gains but performances on probabilistic losses were similar between the two groups. The IGD group also exhibited a shorter response time (Hedge's g = - 0.51; 95%CI = - 0.87 to - 0.15). Meta-regression demonstrated a positive correlation between maximum reward magnitude and PD rate (p < 0.04). However, significant publication bias was noted among the included studies (Egger's test, p < 0.01). In conclusion, individuals with IGD seemed more impulsive in making risky decisions, especially when the potential gains were expected. Our findings not only supported the use of PD for assessing individuals with IGD but may also provide new insights into appropriate interventions.

Resting-state connectome-based support-vector-machine predictive modeling of internet gaming disorder.

Internet gaming disorder (IGD), a worldwide mental health issue, has been widely studied using neuroimaging techniques during the last decade. Although dysfunctions in resting-state functional connectivity have been reported in IGD, mapping relationships from abnormal connectivity patterns to behavioral measures have not been fully investigated. Connectome-based predictive modeling (CPM)-a recently developed machine-learning approach-has been used to examine potential neural mechanisms in addictions and other psychiatric disorders. To identify the resting-state connections associated with IGD, we modified the CPM approach by replacing its core learning algorithm with a support vector machine. Resting-state functional magnetic resonance imaging (fMRI) data were acquired in 72 individuals with IGD and 41 healthy comparison participants. The modified CPM was conducted with respect to classification and regression. A comparison of whole-brain and network-based analyses showed that the default-mode network (DMN) is the most informative network in predicting IGD both in classification (individual identification accuracy = 78.76%) and regression (correspondence between predicted and actual psychometric scale score: r = 0.44, P < 0.001). To facilitate the characterization of the aberrant resting-state activity in the DMN, the identified networks have been mapped into a three-subsystem division of the DMN. Results suggest that individual differences in DMN function at rest could advance our understanding of IGD and variability in disorder etiology and intervention outcomes.