Diagnostic criteria for Internet gaming disorder (IGD), defined as an addiction to Internet games, are proposed as research criteria in section III of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [1
]. IGD is one type of internet addiction and has been associated with mood-related psychopathological symptoms, such as depression and irritability [2
]. This comorbidity could contribute to treatment difficulties and a poor prognosis of addictive disorder [4
], for example, the comorbidity of depression associated with the higher psychosocial burden among subjects with IGD [5
]. Further, comorbidity could indicate a causal relationship between the disorders [6
] or a common factors model [7
], wherein a shared mechanism generally accounts for increased comorbidity. To intervene, the shared mechanism might benefit both disorders. Therefore, understanding the shared mechanism causing comorbidity between IGD and psychopathological symptoms could contribute to successfully developing treatments for them.
1.1. Association between IGD and Emotional Difficulties
The amount of time spent playing online games has been positively correlated with depressive symptoms [8
]. The association between IGD, depression, and hostility were also demonstrated in recent studies [10
]. Gentile et al. reported that IGD could be a cause of depression in adolescents [12
]. Further, Ciarrochi et al. also reported that compulsive internet use predicted poor mental health among adolescents in longitudinal investigation [13
]. These results might indicate that repeatedly excessive online gaming could contribute to emotional difficulties, possibly though impaired daily life functions or their negative consequences. On the other side, addictive behavior, such as online gaming [14
], could be a way of coping with pre-existing emotional difficulties, such as depression [6
]. Depression was reported to predict the incidence of internet addiction and support this claim [15
]. This might suggest that emotional difficulties could possibly contribute to IGD; however, this has not been proved. The possible bidirectional effect between IGD and emotional difficulties deserves future prospective study. On the other hand, an underlying factor, such as emotional regulation, might be associated with both IGD and emotional difficulties, and could contribute to the comorbidity of IGD.
1.2. Emotional Regulation and Depression, Anxiety, Hostility, and IGD
Emotional regulation, also known as emotional self-regulation, was defined by [16
] as the set of cognitive processes that influence emotional responses. Emotional regulation is a complex process that includes the initiation, inhibition, or modulation of aspects of emotion functioning. A previous review demonstrated that interventions that specifically target emotional regulation can not only promote positive emotional regulation but also attenuate associated psychopathological symptoms [17
Two strategies are commonly used for downregulating emotion. The first, reappraisal, comes early in the emotion-generative process and entails changing how a situation is construed in order to reduce its emotional impact. The second, suppression, comes later in the emotion-generative process and entails the inhibition of outward signs of inner feelings [18
]. The two types of emotional regulation are evaluated in The Emotional Regulation Questionnaire, which measures the habitual use of expressive suppression and cognitive re-evaluation. The scale includes items related to the regulation of positive and negative emotions [19
]. According to this measurement, practicing reappraisal is associated with greater positive emotion, improved interpersonal functioning, and well-being. By contrast, practicing suppression is associated with negative emotions and poorer interpersonal functioning. These results suggest that strategies that act early in the emotion-generative process have a different profile of consequences than strategies that act later.
Emotional regulation was associated with depression [20
] and anxiety [21
]. The employment of adaptive emotional regulation strategies (e.g., reappraisal) causes a reduction in stress-induced emotions. Conversely, dysfunctional emotional regulation strategies, such as emotion suppression, appear to influence the pathogenesis of depression. For example, a structural equation modeling study found that expressive suppression mediated the relationship between intensity of negative affect and psychological distress [22
]. In addition, emotional regulation therapy has been reported to be an effective treatment of emotional dysfunctions, such as anxiety or depression [17
]. The literature demonstrates the role for emotional regulation in the development or maintenance of depression and anxiety [20
Fewer studies have evaluated the relationship between emotional regulation and hostility than the relationship between emotional regulation and depression or anxiety. People with lower anger control can reasonably be assumed to display more aggressive behaviors [25
]. A previous study demonstrated the relationship between emotional regulation and anger reactivity [26
]. Hostile cognition is a major factor contributing to anger and aggressive behavior [27
]. However, whether cognitive appraisal can attenuate the role of hostile cognition in depression has not been evaluated.
Depression and emotional regulation are considered risk factors for the development of addictive disorders [28
]. Emotional regulation was reported to predict substance use disorder (specifically, alcohol use disorder [29
]) and has been suggested to have a moderating role in addiction development [30
]. IGD has been reported to be associated with depression, irritability, and anxiety [2
]. Difficulties with emotional regulation are associated with these associated psychopathological symptoms [20
]. Furthermore, poor emotional regulation might contribute to depression [20
] that predicts IGD [15
]. Moreover, excessive online gaming could have negative consequences that could result in stress for individuals with IGD. Appropriate emotional regulation mediates negative effects and psychological stress [22
], whereas impaired emotional regulation might contribute to mood symptoms, such as depression and anxiety. Loton et al. revealed that the coping strategy had been reported to account for the association between video gaming addiction and depression [14
]. It supported the claim that inappropriate emotional regulation might contribute to the association between psychopathological symptoms of IGD. However, the association between emotional regulation and these psychopathological symptoms has not been evaluated among subjects with IGD.
1.3. Study Hypothesis and Objectives
We hypothesized that emotional regulation, cognitive reappraisal, and suppression are associated with IGD, and that individuals with IGD practice less emotional regulation, use fewer reappraisal strategies, and tend to suppress emotions more than does the average person. Furthermore, the deficit in emotional regulation might be correlated with depression, hostility, and anxiety among subjects with IGD. Accordingly, this study evaluated the following: (1) cognitive reappraisal and expressive suppression among individuals with and without IGD, and (2) the associations among cognitive reappraisal, expressive suppression, depression, hostility, and anxiety among subjects with IGD.
People with poor emotional regulation often engage in maladaptive behavior to escape from their emotions, creating risks of a range of mood disorders and addictive disorders [39
]. Thus, such people have been associated with various addictive disorders [29
]. To our knowledge, no previous study has assessed emotional regulation among subjects with IGD. As expected, the present study demonstrated that subjects with IGD have lower cognitive reappraisal and higher expressive suppression. This result is similar to a previous report demonstrating lower cognitive reappraisal in gambling disorder [39
]. Further, our study demonstrated that lower cognitive reappraisal and higher expressive suppression were associated with depression, anxiety, and hostility among subjects with IGD.
Our literature review suggested that those individuals experiencing depression or anxiety have ineffective emotional regulation and difficulties in processing negative emotions [20
]. Cognitive reappraisal is a cognitively-oriented strategy for redefining emotional stimuli in unemotional terms or for reimagining depressive situations [40
]. It comes early in the emotion-generative process and effectively decreases the experience of negative emotions [18
]. By contrast, expressive suppression, coming later in the emotion-generative process, entails the inhibition of outward signs of inner feelings. Suppression is ineffective for down-regulating negative emotions, and people with a history of depression have been reported to spontaneously use this strategy [41
]. Like these previous results, our results demonstrated that subjects with higher depression have lower cognitive reappraisal and higher expressive suppression among both subjects with IGD and controls.
People with IGD experience negative psychosocial consequences from excessive online gaming [42
]. They also experience depression, anxiety, or irritation when they are prohibited from playing games online [1
]. Thus, previous prospective study had suggested that internet gaming disorder or excessive online gaming [8
] contributes to depression. They could reappraisal that this is a logical result of ceasing an excessive, self-gratifying behavior, and that the depression and restlessness could be avoided if they engaged in an alternative, appropriate activity such as exercise. However, without appropriate reappraisal, subjects with IGD could experience depression. Further, continuing to suppress negative emotions rather than reappraising them could leave these emotional difficulties unresolved. Thus, the lower cognitive reappraisal and higher suppression of subjects with IGD could partly account for their vulnerability to depression.
Although there is no report demonstrating the predictive effect of depression on internet gaming disorder, previous reports had suggested that depression predicted incidence of internet addiction [32
]. Subjects with lower cognitive reappraisal that were habituated to use suppression could experience depression under stress [20
]. Online gaming could provide a virtual world for people to escape from their negative emotions [43
] and could buffer stress [44
]. However, if the gaming time could not be well controlled, the repeatedly excessive gaming could result in further negative consequences among vulnerable subjects. It could create a vicious cycle and lead to repeated engagement in online gaming, resulting in increased addiction risk. Anyway, this claim should be further evaluated in prospective study.
Subjects with higher anxiety were more likely to pay attention to threat-related stimuli rather than neutral stimuli [45
]. The continued attention to threat increases their cognitive and emotional response, contributing to anxiety symptoms. The manner in which information was processed in emotional regulation could determine anxiety severity [24
]. The use of suppression as a regulatory mechanism and limited access to emotional regulation strategies, such as cognitive reappraisal, were associated with anxiety [46
]. Thus, dysfunctional emotional regulation contributes to the development of anxiety disorder [24
]. In this study, the anxiety of subjects with IGD is negatively associated with cognitive reappraisal and positively associated with expressive suppression.
In addition, reappraisal facilitates the adaptive processing of anger-inducing situations and contributes to anger regulation [47
]. However, the suppression of anger could increase hostility under stress [48
]. As expected, subjects with IGD habitually suppress emotions, or those unlikely to reappraise their negative cognition exhibited higher levels of hostility in this study. Moreover, suppression of hostility could increase sympathetic activity [49
], as well as the risk of cardiovascular disorder [50
]. Thus, emotional suppression and hostility of subjects with IGD might result in not only emotional difficulty but also cardiovascular risk.
Cognitive control ability is essential and contributes to emotional regulation, such as reappraisal [40
]. Subjects with IGD had impaired cognitive control [51
], similar to people with gambling disorders [52
] and addictive disorder, such as cocaine use disorder [53
]. The impaired cognitive control ability could associate with their impaired cognitive reappraisal in subjects with IGD. Further study is necessary to understand the neurocognitive mechanism of the impaired emotional regulation, such as cognitive control, among subjects with IGD.
4.1. Clinical Implication
The dysfunctional emotional regulation of subjects with IGD was associated with depression, anxiety, and hostility [32
]. Emotional regulation should be well assessed and intervened in among young adults with IGD. Three key steps—emotional awareness, emotional regulation, and exchanging one emotion for another—help people to modify the state, the belief, and the behavior in response to emotion-eliciting events. These interventions for emotional regulation [23
] have been recommended for the treatment of depression [20
]. Evidence-based emotion management strategies, such as emotion-focused therapy [54
], could be provided to young adults with IGD to promote cognitive reappraisal and attenuate expressive suppression strategies and responses. They must become aware that their negative emotions result from the negative consequences of gaming or from the conflicts in their lives. Alternative activities, physical exercise, and further psychological support should be offered to help relieve negative emotions. Furthermore, information and guidance on reappraisal should be provided so that positive thinking can replace negative thinking. This intervention to promote reappraisal and prevent suppression may attenuate their depression, anxiety, and hostility, and prevent the vicious cycle of IGD. However, these claims for the effects of emotional regulation therapy should be evaluated with future clinical research.
This study has three limitations. First, emotional regulation was assessed using a questionnaire only and not through the investigation of real situations. Second, IGD was diagnosed only through diagnostic interviews with the participants, and supplementary information from family members or partners, which could have contributed to verifying the validity of the diagnoses, was not collected. Third, our cross-sectional research design could not confirm causal relationships between emotional regulation and IGD. Besides, the structure equation model had not been utilized to test hypothesized model because of unconfirmed causal relationship.