Antidepressants do not cause violence. As someone who takes antidepressants, I can truthfully say that they have caused me to calm down my emotions. I would be more likely to be violent if I was not taking these antidepressants. Some people who are violent may be on antidepressants, but it is wrong to just blame them for violent behavior.
There is very little evidence that antidepressents are causing violence on a social level. It just has not been produced. If any such evidence exists, it should be presented, but as now, it hasn't been. So for the time being, it must be assumed that this claim is simply false.