Jess I agree abuse is often about control. A lot of controlling individuals have psychological/emotional/psychiatric problems that underly their behaviour. Put any form of disinhibiting substance into these people, and their behaviour can become violent, is my experience.
Steroids are scary drugs and the link between that and violence is established. I wonder about the link between personality and drug of choice. I've met too many angry, violent men whose drugs of choice were steroids, amphetamine, cocaine and alcohol. Many heroin users will use anything if they can't get hold of their drug of choice.
It's grim isn't it. Before anyone points this out, I am aware that some women behave in similarly aggressive ways as the men I'm talking about.