A study reported on by Ars Technica indicates that video games, much ballyhooed (alleged) source of mental, physical and psycho-social ills for the kids who spent a lot of time playing them, don't seem to have had quite as big a negative effect
on those kids as the moral panic of the past few decades would have you believe. Instead, There didn't seem to be an association between the number of games the children reported owning and an increase in risk for conduct disorder. When examining depression among shoot-em-up players, there was evidence for increased risk before the researchers controlled for all the confounding factors, but not afterwards.
Of course, there's a lot of data to go around in the several studies referred to here, and the upshot seems to both less exciting and less simple than "Video games are good, not bad!"