Do violent video games such as 'Mortal Kombat,' 'Halo' and 'Grand Theft Auto' trigger teenagers with symptoms of depression or attention deficit disorder to become aggressive bullies or delinquents（流氓，行为不良的人）? No, according to Christopher Ferguson of Stetson University and independent researcher Cheryl Olson from the US in a study published in Springer's Journal of Youth and Adolescence. On the contrary, the researchers found that the playing of such games actually had a very slight calming effect on youths with attention deficit symptoms and helped to reduce their aggressive and bullying behavior. Ferguson and Olson studied 377 American children, on average 13 years of age, from various ethnic groups who had clinically elevated attention deficit or depressive symptoms. The children were part of an existing large federally funded project that examines the effect of video game violence on youths.

The study is important in light of ongoing public debate as to whether or not violent video games fuel behavioral aggression and societal violence among youths, especially among those with pre-existing mental health problems. Societal violence includes behavior such as bullying, physical fighting, criminal assaults and even homicide. And the news media often draws a link from the playing of violent video games to the perpetrators of school shootings in the United States.

Ferguson and Olson's findings do not support the popular belief that violent video games increase aggression in youth who have a predisposition to mental health problems. The researchers found no association between the playing of violent video games and subsequent increased delinquent criminality or bullying in children with either clinically elevated depressive or attention deficit symptoms. Their findings are in line with those of a recent Secret Service report in which the occurrence of more general forms of youth violence were linked with aggressiveness and stress rather than with video game violence.

Interestingly, the researchers of the current study found a few instances in which video game violence actually had a slight cathartic effect on children with elevated attention deficit symptoms and helped to reduce their aggressive tendencies and bullying behavior. Although Ferguson and Olson warned that their results could not be generalized to extreme cases such as mass homicides, they strongly advocate for a change in general perceptions about the influence of violent video games, even within the context of children with elevated mental health symptoms.

"We found no evidence that violent video games increase bullying or delinquent behavior among vulnerable youth with clinically elevated mental health symptoms," Ferguson stressed. Regarding concerns about some young mass homicide perpetrators having played violent video games, Ferguson stated, "Statistically speaking it would actually be more unusual if a youth delinquent or shooter did not play violent video games, given that the majority of youth and young men play such games at least occasionally."