"In the present study, we examined the association between daily violent video game playing over the past year and depression in a large, ethnically diverse preadolescent sample. We found that playing high-violence video games for ≥2 hours per day is significantly associated with having a higher number of depressive symptoms. This association was consistent across all racial/ethnic subgroups and among boys, and more important, it was observed after controlling for aggression and several violence-related variables. The magnitude of these associations was small (Cohen's d values ranged from 0.12 to 0.25). However, these effect sizes are similar to those reported for the association between playing violent video games and aggression. Overall, our findings indicate that playing violent video games for a substantial amount of time each day over an extended period is significantly associated with depression in preadolescent youth. They also suggest that this association is unique, given that the number of depressive symptoms was not associated either with playing low-violence video games or with time spent playing video games in general."