"In conclusion, we found that, compared with playing low-violence video games for <2 hours per day, playing high-violence video games for ≥2 hours per day was significantly associated with a higher number of depressive symptoms among preadolescent youth. However, the magnitude of the association was small and a causal relationship cannot be inferred. Nevertheless, it should be noted that even these small effect sizes can be of practical importance considering the large number of preadolescent and adolescent youth who regularly play violent video games. More studies are needed to examine the association between playing violent video games and depression in general and among boys in particular. If this association were confirmed, longitudinal studies would then be needed to investigate its causality, persistence over time, underlying mechanisms, and clinical implications."