Kids who are depressed and have delinquents for friends may be the most likely to lash out violently at others, according to a new study in The Journal of Pediatrics.

The amount of time a youth spent watching violent TV or playing violent video games didn't have anything to do with whether he or she would commit violent acts in real life, Dr. Christopher J. Ferguson of Texas A&M University and his colleagues found.

Ferguson and his team also found that while kids whose parents were psychologically abusive to their intimate partners were more likely to engage in violence, being exposed to a parent's physical abuse of a partner wasn't a factor.

Overall, the researchers found, the factors that did increase the risk of violent behavior had pretty small effects. Based on the findings, they say, future research should probably look at groups of risk factors, rather than focusing on a single one.

A lot of media attention tends to get focused on individual factors, like playing violent video games, Ferguson noted, even when there's no evidence that they're connected with violent behavior.

He and his colleagues investigated the interplay among various risk factors for violent behavior by looking at 603 children 10 to 14 years old and their parents or guardians. Most of the children were Hispanic. Fifteen percent of the children said they had committed non-violent crimes, while 12 percent said they had taken part in violent criminal behavior.

As mentioned, the strongest risk factors for violent behavior were depression and having delinquent peers, the researchers found. Others included a parent's psychological abuse of a partner, antisocial personality, negative relationships with adults, and family conflict.

Based on the findings, Ferguson said it probably makes sense to target programs to prevent youth violence at depressed kids who are hanging out with other kids who are probably in the same boat.

The good news, he added, is that youth violence has been going down in the US since the late 1960s. Things are improving for youth globally for the most part, contrary to what most people think today, Ferguson said.

SOURCE: The Journal of Pediatrics, December 2009.