Altered Autonomic Functions and Distressed Personality Traits in Male Adolescents with Internet Gaming Addiction

The executive function, behavioral systems, and heart rate variability in college students at risk of Mobile gaming addiction

OBJECTS

The prevalence of mobile gaming addiction (MGA) has risen as a result of technical advancements that have made it more portable and handier. Emotional distress and a decline in inhibitions might worsen addictions. The study sought to examine the physiological and neuropsychological indicators of MGA.

METHODS

Following the examination of the online activities of 1774 students in their first year, we recruited 13 participants with MGA and 27 controls, utilizing the internet gaming disorder test (IGDT) and problematic mobile gaming questionnaire (PMGQ). They filled daily executive function scale (DEFS), brief symptom rating scale-50 (BSRS-50), and behavior inhibition/activation scale (BIS/BAS). The Iowa gambling task (IGT-2), Stroop color-word test (SCWT), and the digit-span of the Wechsler intelligence scale were administered. The Heart Rate Variability (HRV) was measured at baseline, playing mobile games, and recovery condition. The independent t-test and repeated-measures ANOVA were used for analysis.

RESULTS

There were similar demographics between groups. The MGAs exhibited reduced inhibitions in SCWT, decreased DEFS, less total money in IGT-2, and elevated distress in BSRS. Both groups showed decreased SDNN, very low frequency, and total power during gameplay. However, the F-test indicated interaction effects of the proportion of NN50 divided by total number of NNs and high-frequency during gameplay, indicating an elevated state for MGAs than controls.

CONCLUSION

MGAs exhibit lower executive function, inhibition, and increased negative mood. The MGAs decreased in HRV during gaming, suggesting potential connections to impaired inhibitory control and stress-related responses. Further study is needed to clarify the mechanisms that contribute to MGA and differentiate it from broader frameworks of internet addiction.

Physiological Regularity and Synchrony in Individuals with Gaming Disorder

Individuals with gaming disorder (GD) show emotional dysregulation and autonomic dysfunction in daily life. Although studies have shown that the relaxation method of breathing exercise (BE) improves cardiopulmonary synchrony, the physiological regularity and synchrony of GD remain unclear. In this study, we investigated the regularities of pulse wave (PW), thoracic wall movement (TWM), and abdominal wall movement (AWM) using sample entropy (SE) and assessed the vascular-respiratory and TWM-AWM synchrony using cross-sample entropy (CSE). Twenty individuals with GD and 26 healthy control (HC) individuals participated in baseline, gaming, and recovery stages, both before and after BEs. The results showed that both groups had significantly higher SETWM, SEAWM, and CSETWM-AWM during gaming than baseline. Before BE, CSEPW-TWM and CSEPW-AWM during gaming were considerably higher in the GD group than in the HC group. Compared to before BE, both groups had decreased SETWM and CSETWM-AWM during gaming, particularly in the HC group. Online gaming may induce pulse wave and respiratory irregularities, as well as thoracic-abdominal wall movement asynchrony. Individuals with GD who engage in prolonged gaming periods may exhibit lower vascular-respiratory synchrony compared to the HC group. SETWM, SEAWM, CSETWM-AWM, CSEPW-TWM, and CSEPW-AWM may serve as biomarkers for assessing the risk of GD. BE may improve TWM regularity and vascular-respiratory synchrony during gaming, potentially alleviating addictive behavior.

Biomarkers of Internet Gaming Disorder-A Narrative Review

Since game mechanics and their visual aspects have become more and more addictive, there is concern about the growing prevalence of Internet gaming disorder (IGD). In the current narrative review, we searched PubMed and Google Scholar databases for the keywords "igd biomarker gaming" and terms related to biomarker modalities. The biomarkers we found are grouped into several categories based on a measurement method and are discussed in the light of theoretical addiction models (tripartite neurocognitive model, I-PACE). Both theories point to gaming-related problems with salience and inhibition. The first dysfunction makes an individual more susceptible to game stimuli (raised reward seeking), and the second negatively impacts resistance to these stimuli (decreased cognitive control). The IGD patients' hypersensitivity to reward manifests mostly in ventral striatum (VS) measurements. However, there is also empirical support for a ventral-to-dorsal striatal shift and transition from goal-directed to habitual behaviors. The deficits in executive control are demonstrated in parameters related to the prefrontal cortex (PFC), especially the dorsolateral prefrontal cortex (DLPFC). In general, the connection of PFC with reward under cortex nuclei seems to be dysregulated. Other biomarkers include reduced P3 amplitudes, high-frequency heart rate variability (HRV), and the number of eye blinks and saccadic eye movements during the non-resting state. A few studies propose a diagnostic (multimodal) model of IGD. The current review also comments on inconsistencies in findings in the nucleus accumbens (NAcc), anterior cingulate cortex (ACC), and precuneus and makes suggestions for future IGD studies.

Altered Heart Rate Variability During Mobile Game Playing and Watching Self-Mobile Gaming in Individuals with Problematic Mobile Game Use: Implications for Cardiac Health

Introduction

The surge in mobile gaming, fueled by smartphone and internet accessibility, lacks a comprehensive understanding of physiological changes during gameplay.

Methods

This study, involving 93 participants (average age 21.75 years), categorized them into Problematic Mobile Gaming (PMG) and non-problematic Mobile Gaming (nPMG) groups based on Problematic Mobile Gaming Questionnaire (PMGQ) scores. The PMGQ is a 12-item scale developed in Taiwan to assess symptoms of problematic mobile gaming. The research delved into heart rate variability (HRV) alterations during real-time mobile gaming and self-gaming video viewing.

Results

Results showed that the PMG group significantly presents a lower root mean square of successive differences (RMSSD), and High Frequency (lnHF) than does the nPMG group (F=4.73, p=0.03; F=10.65, p=0.002, respectively) at the baseline. In addition, the PMG group significantly displayed elevated HF and low-frequency to high-frequency (LF/HF) in the mobile-gaming (F=7.59, p=0.007; F=9.31, p=0.003) condition as well as in the watching self-gaming videos (F=9.75, p=0.002; F=9.02, p=0.003) than did the nPMG.

Conclusion

The study suggests targeted interventions to mitigate autonomic arousal, offering a potential avenue to address adverse effects associated with problematic mobile gaming behavior. The PMG group displayed increased craving scores after real-time mobile gaming and watching self-gaming video excerpts, unlike the nPMG group. Elevated LF/HF ratios in frequent gaming cases heightened autonomic arousal, presenting challenges in relaxation after mobile gaming. These findings contribute to a nuanced understanding of the complex interplay between mobile gaming activities, physiological responses, and potential intervention strategies.

Heart Rate Variability during Online Video Game Playing in Habitual Gamers: Effects of Internet Addiction Scale, Ranking Score and Gaming Performance

Previous studies have demonstrated that individuals with internet gaming disorder (IGD) display abnormal autonomic activities at rest and during gameplay. Here, we examined whether and how in-game autonomic activity is modulated by human characteristics and behavioral performance of the player. We measured heart rate variability (HRV) in 42 male university student habitual gamers (HGs) when they played a round of League of Legends game online. Short-term HRV indices measured in early, middle and late phases of the game were compared between the players at high risk of developing IGD and those at low risk, as assessed by the revised Chen Internet addiction scale (CIAS-R). Multiple linear regression (MLR) was used to identify significant predictors of HRV measured over the whole gameplay period (WG), among CIAS-R, ranking score, hours of weekly playing and selected in-game performance parameters. The high-risk players showed a significantly higher low-frequency power/high-frequency power ratio (LF/HF) relative to the low-risk players, regardless of game phase. MLR analysis revealed that LF/HF measured in WG was predicted by, and only by, CIAS-R. The HRV indicators of sympathetic activity were found to be predicted only by the number of slain in WG (NSlain), and the indicators of parasympathetic activity were predicted by both CIAS-R and NSlain. Collectively, the results demonstrated that risk of developing IGD is associated with dysregulated autonomic balance during gameplay, and in-game autonomic activities are modulated by complex interactions among personal attributes and in-game behavioral performance of the player, as well as situational factors embedded in game mechanics.

The relationship between internet addiction and risk of suboptimal health status among Chinese college students

Internet addiction (IA) is a prevalent trend among college students, and the relationship between severe IA and poor health status among college students has been well established. However, whether IA is associated with suboptimal health status (SHS) in college students is unclear. This study aimed to investigate the association between IA and SHS risk in Chinese college students. We conducted a cross-sectional study to assess whether IA was related to SHS risk in 2265 college students in Shenyang, China. SHS was assessed using the Suboptimal Health Status Questionnaire with a cutoff score of ≥35 to document SHS. IA was assessed using the validated 20-item Young's Internet Addiction Test with cutoff scores of 31-49 and 50-100 for mile and moderate-to-severe cases, respectively. The prevalence rate of SHS was 54.0%. After adjusting for potential confounding factors, the IA categories were positively related to a higher risk of SHS. The odds ratios (95% confidence intervals) for SHS across IA categories were 1.00, 7.66 (6.00, 9.78), and 27.93 (20.95, 37.24) (P for trend: <.001) after adjusting for multiple confounding factors. This is the first cross-sectional study to demonstrate that IA is independently associated with SHS. This finding suggests that IA is a negative risk factor for SHS.

Can Heart Rate Variability be Viewed as a Biomarker of Problematic Internet Use? A Systematic Review and Meta-Analysis

Heart rate variability (HRV) has been used to explore the parasympathetic activity of individuals with problematic Internet use (PIU), but the results are controversial. We conducted a systematic review and meta-analysis of studies comparing HRV in PIU individuals and healthy participants from several databases. HRV was analyzed according to the parasympathetic activity in hierarchical order (primary analysis), and the total variability (secondary analysis). The baseline HRV and HRV reactivity were both considered. Of the 106 studies screened, 12 were included in the quantitative analysis. Significant differences were observed for baseline HRV in PIU individuals compared to the controls. Regarding HRV reactivity, PIU individuals did not have a significantly lower HRV value during pleasant or unpleasant stimuli. In summary, PIU individuals and healthy subjects had significantly different resting state parasympathetic activity. The finding of HRV reactivity in PIU individuals awaits further investigation.

Effect of Exercise Intervention on Internet Addiction and Autonomic Nervous Function in College Students

Objective

To investigate the effects of 12-week physical exercise (jogging, basketball, and outdoor training) on sleep quality, harmful mood, and heart rate variability (HRV) in college students with Internet addiction.

Methods

46 college students with Internet addiction were chosen and then randomly assigned to the Internet addiction group (IA, n = 23) and the Internet addiction exercise group (IA+EX, n = 23). The subjects in the IA+EX group underwent physical exercise for 12 weeks (three times per week), and the IA group did not perform regular physical exercise during the experiment. Then, the degree of Internet addiction, depression, and sleep quality were evaluated by using Young's Internet Addiction Test (IAT) scale, Center for Epidemiologic Studies Depression (CES-D) scale, and Pittsburgh sleep quality index (PSQI); HRV were measured by using Polar Team 2 before and after physical exercise intervention.

Results

(1) After the 12-week exercise, compared to preexercise intervention, the scores of IAT, CES-D, and PSQI significantly decreased (t = 12.183, 9.238, 5.660; P < 0.01) in the IA+EX group; compared with the IA group, the scores of IAT, CES-D, and PSQI significantly decreased (t = 2.449, 3.175, 4.487; P < 0.05, P <0.01) in IA+EX group college students with Internet addiction. (2) After the 12-week exercise, compared to preexercise intervention, LFn and the ratio of LF/HF significantly decreased (t = 5.650, 3.493; P < 0.01) and HFn significantly increased (t = −2.491, P < 0.05) in the IA+EX group; there were no significant differences in the above indexes before and after the experiment in the IA group (P > 0.05). Compared with the IA group, HFn significantly increased (t = 3.616, P < 0.01) and the ratio of LF/HF significantly decreased (t = 2.099, P < 0.01) in IA+EX group college students with Internet addiction; there was no significant difference in LFn between the two groups.

Conclusion

Long-term physical exercise could significantly reduce the degree of Internet addiction and depression, improve sleep quality, and balance sympathetic parasympathetic function of college students with Internet addiction, indicating that exercise-based intervention might be an effective way to alleviate or even eliminate Internet addiction.

“Game (not) Over”: A Systematic Review of Video Game Disorder in Adolescents

This study aims to characterize video game use disorder in adolescents, identifying the particularities of those who present it, its effects at the brain level, related factors, and existing measurement instruments. A systematic review of the scientific publications available in Scopus was carried out, between the period 2014-2018 on video game use disorder in adolescents. Adolescents with this disorder are characterized by being mostly men, spending more time daily and weekly playing than adolescents without this disorder, showing diverse symptoms in the behavioral, affective, and cognitive areas. At brain level, it is referred that in this disorder there is an increase and decrease in the activation of specific areas of the brain. Likewise, the presence of some psychological disorder and impulsivity are considered factors that increase the risk of suffering from it. However, there are protective factors as school commitment and parental supervision, among others. How to cite: Rojas-Jara, C., Polanco-Carrasco, R., Navarro-Castillo, R., Faúndez-Castillo, F., & Chamorro-Gallardo, M. (2022). “Game (not) Over”: A Systematic Review of Video Game Disorder in Adolescents. Revista Colombiana de Psicología, 31(2), 45-64. https://doi.org/10.15446/rcp.v31n2.90741

Online gaming addiction in youth: Some comments on Rosendo-Rios et al. (2022)

A recent systematic review examining online gaming addiction among children and young adults was published in Addictive Behaviors (i.e., Rosendo-Rios, Trott & Shukla, 2022). However, dozens of papers were missing from the review. One of the reasons why so many studies were not in the review is likely to be because of the search terms used. None of the search terms included the words 'adolescent', 'adolescence', 'emerging adults', 'excessive gaming', 'gaming disorder', 'video game addiction' or 'problematic gaming'. Moreover, studies were also included in the review if the mean age of the total sample was 25 years or below. This meant that some studies in the review included some participants who were not children, adolescents or emerging adults. It also meant that many studies were not included that had mean ages below the age of 26 years because they were not picked up by the search strategy. Given the high number of studies that were not included in the review, readers should view this systematic review as 'suggestive' of research in the area of problematic gaming in youth rather than 'definitive'.

Neurophysiologic Reactions during Heart Rate Variability Biofeedback Session in Adolescents with Different Risk of Internet Addiction

The aim of this study was to determine electroencephalogram (EEG) in a session of heart rate variability biofeedback (HRV BF) in adolescents with different Internet addiction (IA) risks. In total, 100 healthy adolescents aged 16–17 years with minimal risk of IA (Group I, 35%), pronounced risk of IA (Group II, 51%), and stable pattern of IA (Group III, 14%) using the Chen Internet Addiction Scale were examined. HRV and EEG parameters were determined at baseline (5 min), and then during the short-term HRV BF session (5 min), in order to increase the total power (TP, ms²) of the HRV spectrum. Against the background of an increase in the TP and a decrease in sympathetic activity, an increase in alpha EEG was revealed, especially in Groups I and II. The greatest increase in the power of beta₁-activity of EEG in the frontal, central, and temporal brain regionswas found in Groups I and II. In adolescents with a pronounced risk of IA, HRV BF is accompanied by a severe activation of the brain systems, while in persons with a stable type of IA, the least brain reactivity is shown, especially in the beta₁ EEG band.

Profile of Treatment-Seeking Gaming Disorder Patients: A Network Perspective

The increasing presence of gaming disorder in recent years has led to major efforts to identify the specific predictors that have a high impact on the profile of people seeking treatment for this mental condition. The purpose of this study was to explore the network structure of the correlates of gaming disorder considering sociodemographic features and other clinical symptoms. Network analysis was applied to a sample of patients who met clinical criteria for gaming disorder (n = 117, of ages ranging from 15 to 70 yrs-old). Variables considered in the network included sex, age, socioeconomic position, global emotional distress, age of onset and duration of the gaming disorder, personality traits and the presence of other addictive behaviors (tobacco, alcohol and behavioral addictions). The central nodes in the network were global psychological distress, chronological age, and age of onset of gaming related problems. Linkage analysis also identified psychopathological status and age as the variables with the most valuable information in the model. The poorest relevance in the analysis was for the duration of gaming problems and socioeconomic levels. Modularity analysis grouped the nodes within four clusters. Identification of the variables with the highest centrality/linkage can be particularly useful for developing precise management plans to prevent and treat gaming disorder related problems.

Extended classifier system with continuous real-coded variables for feature extraction of instantaneous pulse-rate variability and respiration of individuals with gaming disorder

Background

Individuals with gaming disorder (GD) exhibit autonomic nervous system responses that indicate dysfunctional emotion regulation. Pulse rate variability (PRV) is a valuable biomarker for investigating the autonomic function of patients with mental disorders. Because individuals with GD dynamically regulate emotions during gaming, the PRV response relating to GD is not well understood. To investigate the dynamic PRV responses of individuals with GD, this study proposed the indexes of instantaneous PRV (iPRV) and instantaneous respiratory frequency (IF_resp) of arterial blood pressure signals using empirical mode decomposition and normalized direct-quadrature algorithms. iPRV consists of low-frequency (LF), high-frequency (HF), and very high-frequency (VHF) bands. Moreover, a novel method of extended classifier system with continuous real-coded variables (XCSR) was used to detect GD and extract GD-related iPRV features using iPRV and IF_resp as input data.

Results

A total of 32 college students without depressive and anxiety symptoms or cardiovascular diseases were recruited in this study. Participants were grouped into the high-risk GD and low-risk GD using both Chen Internet Addiction Scale and Internet Gaming Disorder Questionnaire. Their arterial blood pressures signals were measured while they watched gameplay videos with negative or positive emotional stimuli. Seven participants with high-risk GD exhibited significantly increased normalized VHF (nVHF) PRV and IF_resp readings and significantly decreased normalized LF (nLF) PRV readings and LF/HF PRV ratios (from baseline) during negative or positive gameplay videos stimuli. These participants also exhibited higher nVHF PRV and lower nLF PRV readings and LF/HF PRV ratios when they experienced negative gameplay video stimuli relative to 17 participants with low-risk GD. The classification accuracy of the XCSR reached 90% for both negative and positive video stimuli, and nVHF PRV was most frequently used to detect GD risk.

Conclusions

iPRV and IF_resp can be used to detect GD and analyze the autonomic mechanism of individuals with GD.

Cardiovascular response to physical exercise and the risk of Internet addiction in 15-16-year-old adolescents

BACKGROUND AND AIM

Subjective symptoms of Internet addiction (IA), such as interpersonal and health-related problems (IH-RP), do not correlate with objective physiological parameters. This study aimed to investigate the cardiovascular reactivity after physical exercise in 15-16-year-old adolescents showing different severities of symptoms of health-related problems due to Internet overuse.

METHODS

This study included 20 healthy adolescents (boys, 15-16 years) with different risks of IA (by the Chen internet addiction scale [CIAS]). The physical exercise test was to perform a standing broad jump three times. The arterial blood pressures and heart rates were recorded before, immediately after, and at 4 minutes of rest after exercise.

RESULTS AND DISCUSSION

The total sample of adolescents was divided into two groups, that is, those with IH-RP scores of 12 or less (Group I, n = 12) and those scoring more than 12 points (Group II, n = 8). The diastolic blood pressure significantly increased after exercise in group II, whereas it remained stable in group I. The heart rate in group I tended to increase, but the changes were not statistically significant. Group II adolescents showed significant increases in heart rate, and at rest, this parameter was significantly higher than the baseline value.

CONCLUSIONS

Adolescents with a risk of IA and severe symptoms of interpersonal and health-related problems had increased sympathetic activity during and after speed-strength physical exercise compared to those without the aforementioned symptoms.

Heart Rate Variability, Time Estimation and Internet-Dependent Behaviour in 16-17-Year-Old Adolescents: A Study in Russian Arctic

Internet-dependent behaviour in adolescents can contribute to a change in the function of the nervous system, which is reflected in the violation of time perception and autonomic regulation of the heart rate. The aim of the study was to determine groups of individuals with different risks of Internet addiction (IA) in relation to heart rate variability (HRV) parameters and the efficiency of time estimation in adolescents aged 16–17 years living in the Russian Arctic. Adolescents aged 16–17 years (n = 49–32 females, 17 males) living in Yamalo-Nenets Autonomous Okrug (Russia) were observed. Chen Scale Internet Addiction (CIAS) was used. The duration of an individual 1 min was determined. HRV parameters were determined using the "Varicard" equipment (Russia). In 16–17-year-old adolescents with different levels of risk of developing IA, including signs of IA, we revealed a high severity of symptoms of withdrawal from Internet use, difficulty in time estimation against the background of sympathicotonia and a decrease in vagal regulation of heart rate. In individuals with minimal symptoms of withdrawal from Internet use, the total HRV and vagal activity remain higher than in those with severe withdrawal symptoms, and their time estimation remains effective.

Relationships of internet gaming reasons to biological indicators and risk of internet gaming addiction in Korean adolescent male game users

BACKGROUND

There are no standard diagnostic criteria or interventions for internet gaming addiction (IGA) even though IGA is one of the most pervasive public health issues among youth worldwide. Internet gaming reasons or motivations have been studied as a potential predictor of IGA, but the results have been inconsistent and biological indicators of gaming reasons have rarely been studied. We sought to (1) identify categories of internet gaming reasons, (2) examine the relationship of gaming reasons to risk of IGA, and (3) describe biological indicators associated with reasons for gaming.

METHODS

We used a multi-phase cross-sectional design including individual interviews; focus group discussion; and descriptive, comparative analysis. Fifteen Korean adolescent male internet gamers participated in individual interviews and eight participated in a focus group aimed at identifying reasons for internet gaming. Using the identified gaming reasons from these sources we surveyed 225 adolescent game users using a self-report questionnaire. Participants provided blood samples for assessment of norepinephrine (NE) and serum cortisol.

RESULTS

We identified four major categories of internet gaming reasons: entertainment, getting along with friends, stress relief, and habitual gaming. The habitual group showed significantly greater risk of IGA than the other groups (p < .001) and the lowest plasma NE levels (p = .035), possibly indicating an alteration in autonomic function.

CONCLUSION

Health care providers are encouraged to screen adolescents for excessive internet gaming and to intervene with those who report habitual gaming behaviors. When feasible, assessment of biological indicators, such as plasma NE, may help to identify youth at greatest risk of IGA.

Problematic Internet Use: The Relationship Between Resting Heart Rate Variability and Emotional Modulation of Inhibitory Control

A growing literature suggests that problematic Internet use (PIU) is associated with defective inhibitory control. In this study, we sought to investigate the ability to inhibit prepotent motor responses in an emotional context in individuals with PIU, and to examine the relationship between inhibitory control and resting heart rate variability (HRV), which is regarded as a measure of self-regulation and adaptability. Problematic users (PU, n = 20) and nonproblematic users (non-PU, n = 20) completed an emotional Go/NoGo task, involving the presentation of unpleasant, pleasant, and neutral pictures. The electrocardiogram was recorded at rest for a 3-minute period. PU showed lower resting HRV, relative to non-PU. Although reaction times (RTs) to Go task stimuli were not faster in PU, relative to non-PU, accuracy rates were significantly lower among PU, irrespective of pictures' emotional content. Only among PU did lower resting HRV predict lower response accuracy in pleasant and unpleasant Go trials and less efficient task performance (combining RTs to Go trials and accuracy to NoGo trials) upon presentation of unpleasant stimuli. Our findings suggest that reduced HRV is a potential indicator of defective inhibitory control in an emotional context in PIU.

Internet Gaming Disorder and Its Associated Personality Traits: A Systematic Review Using PRISMA Guidelines

For most individuals, videogame playing is a fun and enjoyable activity that brings many benefits. However, for a small minority, the activity can be problematic and has led to much research into “gaming disorder.” In explanations concerning the contributory factors to gaming disorder, personality traits have been increasingly studied. The present paper carried out a systematic review of available literature using Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. The inclusion criteria were (i) publication date between 2000 and 2018, (ii) being an empirical study, (iii) written in English and Turkish languages (the two languages spoken by the authors), (iv) published in a scholarly peer-reviewed journal, and (v) conducted an assessment of IGD and personality traits objectively. Studies were excluded from the review if they were (i) single-case studies, (ii) unpublished thesis and dissertation studies, and (iii) not published in a peer-reviewed journal. Following these procedures, 21 eligible empirical studies were included. Results demonstrated that 24 distinct personality traits had been examined in relation to IGD and that some of these traits were demonstrated as risk factors for gaming addiction (although not always in the same direction).

A Novel Cue-Induced Abdominal Reaction Analysis for Internet Gaming Disorder

Individuals with Internet gaming disorder (IGD) frequently play online games to achieve satisfaction. Numerous signal processing questions regarding the negative consequences and characteristic respiration in a long-term sitting posture remain unanswered. This study recruited 50 individuals with high-risk and low-risk IGD (HIGD and LIGD); these participants were taught to perform a specific respiration during game-film stimuli. The instantaneous frequencies on abdominal movement (f_DF) were calculated with ensemble empirical mode decomposition (EEMD). The difference value (Δf_DF) between rest and stimulus statuses was calculated and found that HIGD showed Δf_DF values of 0.060 during positive stimuli and 0.055 during negative stimuli before the exercise but 0.020 and 0.016, respectively, after the exercise. However, the Δf_DF value for those with LIGD during negative stimuli before the exercise was 0.013, and it increased to 0.025 after the exercise. This is the first approach to IGD discrimination toward abdominal response with EEMD.

Bio-psychosocial factors of children and adolescents with internet gaming disorder: a systematic review

Previous large-scale studies suggest that internet gaming disorder (IGD) among children and adolescents has become an important public concern. Minors are known to be particularly susceptible to problematic internet gaming use owing to age-related underdevelopment of cognitive control. It has been shown that precursors of addictions appear during adolescence; therefore, prevention efforts must be established targeting minors who have their first experience with addictive substances and behaviors during pubescence. Since the DSM-5 classification of IGD in 2013, studies on IGD have drastically increased in number. Thus, we performed an updated review of studies of IGD in children and adolescents to assess the clinical implications of IGD. The search included all publication years, using PubMed, MEDLINE, and PsycINFO. Across studies, the presence of IGD had a negative effect on sleep and schoolwork in minors. Additionally, family factors, including the quality of parent-child relationships, were important social factors in minors with IGD. Brain imaging studies indicate that impaired cognitive control in minors with IGD is associated with abnormal function in the prefrontal cortex and striatum. Persistent pathological online game use from childhood may aggravate abnormal brain function; therefore, preventive care and early intervention are increasingly important. Although extant research supports the effectiveness of cognitive behavioral therapy for minors with IGD, effective psychological intervention for minors with IGD is an urgent issue that requires further research. This review, which presents updated findings of IGD in minors, is expected to contribute to the development of future research and be useful in clinical practice in the field of child and adolescent psychiatry.

Association between internet gaming addiction and leukocyte telomere length in Korean male adolescents

Internet gaming addiction (IGA) has been associated with many negative health outcomes, especially for youth. In particular, the potential association between IGA and leukocyte telomere length (LTL) has yet to be examined. In this study we compared LTL in Korean male adolescents with and without IGA and examined the association between LTL and autonomic functions. Specifically, plasma catecholamine, serum cortisol, and psychological stress levels were measured as autonomic functions. Data were collected using participant blood samples analyzed for LTL, catecholamine, and cortisol levels and a set of questionnaires to assess IGA and psychological stress levels of the participants. The LTL measurements were made using a qPCR-based technique, and the relative LTL was calculated as the telomere/single copy (T/S) ratio. T/S ratio was significantly shorter in the IGA group than in the non-IGA group (150.43 ± 6.20 and 187.23 ± 6.42, respectively; p < .001) after adjusting for age. In a univariate regression analysis, age, daily Internet gaming time, IGA score, and catecholamine level (epinephrine and norepinephrine) were significantly associated with T/S ratio. However, duration of Internet gaming exposure, dopamine, cortisol, and psychological stress levels were not found to be associated with T/S ratio. In the final multiple linear regression model, age, daily Internet gaming time, and epinephrine level showed statistically significant relationships with T/S ratio. Our results indicate that in addition to age, involvement in excessive Internet gaming may induce LTL shortening in male adolescents, which may be partially attributable to changes in autonomic function such as catecholamine level. These findings further understanding of the health effects of IGA and highlight the need for screening and intervention strategies for male adolescents with IGA.

Genetic association of human Corticotropin-Releasing Hormone Receptor 1 (CRHR1) with Internet gaming addiction in Korean male adolescents

BACKGROUND

The number of people with Internet gaming addiction (IGA) is increasing around the world. IGA is known to be associated with personal characteristics, psychosocial factors, and physiological factors. However, few studies have examined the genetic factors related to IGA. This study aimed to investigate the association between IGA and stress-related genetic variants.

METHODS

This cross-sectional study was conducted with 230 male high school students in a South Korean city. We selected five stress-related candidate genes: DAT1, DRD4, NET8, CHRNA4, and CRHR1. The DAT1 and DRD4 genes were genotyped by polymerase chain reaction, and the NET8, CHRNA4, and CRHR1 genes were genotyped by pyrosequencing analysis. We performed a Chi-square test to examine the relationship of these five candidate genes to IGA.

RESULTS

Having the AA genotype and the A allele of the CRHR1 gene (rs28364027) was associated with higher odds of belonging to the IGA participant group (p = .016 and p = .021, respectively) than to the non-IGA group. By contrast, the DAT1, DRD4, NET8, and CHRNA4 gene polymorphisms showed no significant difference between the IGA group and control group.

CONCLUSIONS

These results indicate that polymorphism of the CRHR1 gene may play an important role in IGA susceptibility in the Korean adolescent male population. These findings provide a justification and foundation for further investigation of genetic factors related to IGA.

Altered Heart Rate Variability During Gameplay in Internet Gaming Disorder: The Impact of Situations During the Game

Internet gaming disorder (IGD) is characterized by a loss of control over gaming and a decline in psychosocial functioning derived from excessive gameplay. We hypothesized that individuals with IGD would show different autonomic nervous system (ANS) responses to the games than those without IGD. In this study, heart rate variability (HRV) was assessed in 21 young males with IGD and 27 healthy controls while playing their favorite Internet game. The subjects could examine the game logs to identify the most and least concentrated periods of the game. The changes in HRV during specific 5-min periods of the game (first, last, and high- and low-attention) were compared between groups via a repeated measures analysis of variance. Significant predictors of HRV patterns during gameplay were determined from stepwise multiple linear regression analyses. Subjects with IGD showed a significant difference from controls in the patterns of vagally mediated HRV, such that they showed significant reductions in high-frequency HRV, particularly during the periods of high attention and the last 5 min, compared with baseline values. A regression analysis showed that the IGD symptom scale score was a significant predictor of this reduction. These results suggest that an altered HRV response to specific gaming situations is related to addictive patterns of gaming and may reflect the diminished executive control of individuals with IGD while playing Internet games.