Internet Gaming Disorder, Problem Gambling Symptoms and Mental Health in Spanish Adolescents: A Cross-Sectional Study on the Role of Microtransactions and Loot Boxes

Background/Objectives: Adolescent mental health problems have increased in recent years, with growing concern about the impact of digital behaviors such as problematic video game use and gambling. Internet Gaming Disorder (IGD) and Problem Gambling Symptoms may share psychological risk markers, but evidence in Spanish adolescents is limited. This study aimed to examine the relationship between IGD, problem gambling symptoms, and mental health, and to identify sociodemographic, psychological, and behavioral factors associated, including microtransactions and loot boxes. Methods: A cross-sectional study was conducted with secondary education students from Extremadura (Spain). The final sample included 343 participants. Measures included an ad hoc questionnaire on video game use, the IGDS9-SF, SOGS-RA, and the Strengths and Difficulties Questionnaire (SDQ). Descriptive analyses, Spearman correlations, and multivariable regression (Poisson and negative binomial) were performed. Results: IGD and gambling were positively correlated (Spearman’s ρ = 0.386, p < 0.001) and associated with higher mental health difficulty scores (IGD: ρ = 0.299, p < 0.001; gambling: ρ = 0.214, p < 0.001). Male gender was associated with both outcomes (IGD: incidence rate ratio [IRR] = 1.21 [95% Confidence Interval: 1.13–1.30]; gambling: IRR = 2.90 [1.85–4.60]). Microtransactions were associated with both behaviors (IGD: IRR = 1.17 [1.09–1.25]; gambling: IRR = 1.74 [1.19–2.54]), while loot box use was related only to IGD (IRR = 1.13 [1.05–1.21]). Total SDQ score was positively associated with both IGD (IRR = 1.02 [1.02–1.03]) and gambling (IRR = 1.10 [1.06–1.13]). Younger age was associated with higher IGD scores (IRR = 0.97 [0.96–0.99]). Conclusions: There are similarities in the associations among the examined factors and increased scores of IGD and gambling in adolescents, particularly male gender, higher mental health difficulties scores, and involvement in monetized gaming systems. School-based, family, and public health prevention strategies may benefit from addressing the importance of psychological well-being and increase awareness of the potential risks associated with digital gaming practices.