There's a fair bit of research on this. The most consistent observation is that being a victim of family violence is a risk factor for mental disorders, including PTSD. That is the primary linkage between family violence and traumatic stress disorders.
That being said, there are a number of studies, including research that we have done ourselves, that do show a correlation between having post-traumatic stress disorder and incidentally depression as being both a perpetrator of family violence and a victim of family violence. I think most people in the field who've looked at this acknowledge that there is likely a linkage there.
That said, it is only one factor of many that influences family violence. The average person with PTSD hasn't hurt anybody. They're minding their own business, trying to go about their business in the best way they can. I worry, when we talk about these things, that people get the picture that our service members with PTSD are homicidal, suicidal maniacs, which is profoundly unfair and very unhelpful for them as they reintegrate back into society.
So there is a linkage there, but let's not take it out of context.