Luoya Zhang

Objective The nine diagnostic criteria for Internet Gaming Disorder (IGD) proposed in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) have been widely adopted, but have also faced significant criticism. This study evaluated the psychometric properties of the nine DSM-5 criteria for IGD using item response theory (IRT).Methods Four DSM-5-based scales, including the Game Addiction Scale, the Internet Gaming Disorder Scale Short-Form, the Ten- Item Internet Gaming Disorder Test, and the Internet Gaming Disorder Scale, were administered to 1,530 Chinese adolescents and young adults. IRT models were used to assess the psychometric properties of these criteria. The potential for differential item functioning (DIF) related to sex and between adolescents and adults was also evaluated.Results All nine DSM-5 criteria demonstrated very high to perfect discrimination (a >1.38), providing substantial diagnostic information (item information >0.476) for diagnosing IGD. These scales, despite variations in wording and scoring methods, exhibited strong correlations in total scores (r≥0.502, p<0.001) and high consistency (Kendall’s W ≥0.656, p<0.05) concerning the fitted IRT parameters. Among the nine criteria, escape showed the lowest cross-scale discrimination, item information, and difficulty. In contrast, withdrawal showed the highest item information and discrimination, and the second highest difficulty. Additionally, there was no evidence of DIF related to sex or age (adolescents vs. adults) across nearly all scale items.Conclusion These findings indicate that the nine DSM-5 criteria generally possess acceptable psychometric properties for diagnosing IGD. Notably, withdrawal may represent a core symptom of IGD. Conversely, escape demonstrated inferior performance compared to the other eight criteria, indicating a potential need for further revision.

Background and aims: The shift from goal-directed to habitual control is a well-documented phenomenon in addiction research and is considered a critical factor in the development and maintenance of addictive behaviors. Whether Internet Gaming Disorder (IGD) is also associated with such a shift is not yet clear. The current study investigated the imbalance between goal-directed and habitual control in individuals with IGD. Methods: Goal-directed and habitual control, as informed by model-based (MB) and model-free (MF) learning, were assessed with a two-step sequential decision-making task during functional magnetic resonance imaging (fMRI) in 33 young adults with IGD and 32 healthy controls (HCs). Self-report data regarding addictive symptoms, game craving, and impulsivity were also collected. Results: Individuals with IGD relied more heavily on habitual control to guide subsequent choices compared to HCs. According to a hybrid reinforcement learning model, individuals with IGD also exhibited a reduced MB weight related to HCs, which was correlated with more severe addictive symptoms. fMRI results revealed that individuals with IGD showed increased MF reward prediction error (RPE _MF ) signals in the right triangular part of the inferior frontal gyrus (IFG). No significant group differences were found in the contrast of RPE _MB maps. Discussion and conclusions: Our study provides both behavioral and neural evidence highlighting an imbalance between goal-directed and habitual control, favoring habitual control in individuals with IGD. This imbalance is associated with the severity of addictive symptoms, suggesting an indication of habit inclination in IGD could potentially contribute to the development or maintenance of the addiction.