Dose-Response Association Between Parental Gaming Time and Internet Gaming Disorder of Adolescents and Parents: A Longitudinal Dyadic Study

Background: Parental gaming has become increasingly common, yet its dose–response relationship with parental and adolescent Internet gaming disorder (IGD) remains unclear. Methods: A one-year, two-wave longitudinal study was conducted among parent–child dyads in Hong Kong. Adolescents completed anonymous questionnaires in classrooms, and parents completed online surveys. Generalized additive models (R version 4.1.3) were used to assess non-linear associations between parental gaming time and parental IGD symptoms/adolescent IGD, with the nadir defined as a "minimum-risk threshold”. When no non-zero "minimum-risk threshold” was identified, parental gaming time was categorized into three groups (ie, non-gamers, below and over the selected cutoff) stepwise starting from the available smallest non-zero value (0.5 hours/day (h/d)). Mixed regression models were used to identify a "low-risk gaming level” where gaming above the cutoff showed a significantly higher risk than both lower categories. Gender-specific subgroup analyses were conducted. Results: A total of 712 parent–child dyads (50.4% girls; 80.8% mothers) were included (follow-up rate: 55.8%). Parental gaming time showed a monotonic positive association with parental IGD symptoms and an inverted U-shaped association with wide CIs at parental gaming times above 4 h/d with adolescent IGD, without showing a non-zero "minimum-risk threshold”. Compared with non-gamers and gaming for 0.5 h/d, parents gaming exceeding 0.5 h/d was associated with higher parental IGD symptoms (> 0.5 h/d vs non-gamers: b (95% CI) = 2.409 (2.280, 2.538); > 0.5 h/d vs 0.5 h/d: 1.787 (1.603, 1.972)) and adolescent IGD (OR (95% CI)=11.124 (6.658, 18.584); 5.119 (2.684, 9.765)). Similar findings were observed in fathers, mothers, boys and girls. Conclusion: While no non-zero "minimum-risk threshold” was identified, limiting gaming to 0.5 h/d or less may be considered a pragmatic "low-risk gaming level” for parents. It preserves parents’ enjoyment of gaming while maintaining a relatively low IGD risk across two generations. It is worth noting that the observed findings may primarily reflect female caregivers’ gaming behaviors and may not be generalizable to male caregivers. Keywords: internet gaming disorder, parent-child dyads, threshold, longitudinal