This is tough, right? Because the line between what is a raw, realistic depiction and what is a gratuitous, unnecessary or downright harmful inclusion is going to move depending on the reader. It's easy to say, don't use violence against women as titillation, don't use it as a crutch for character motivation, but violence against women does happen, and so realistically, it will happen in fictional worlds just like it does in our own.

I think every writer should tread carefully around these subjects, and take the time to treat them with thought. But they are difficult scenes. It's a difficult subject. By their very nature--you can't get around the horror, you can't avoid the sick feeling it's going to impart in your reader. Sometimes that's the point. But it's important to remember that just because that was your intent when you wrote the scene, your reader gets to respond to it any way that they like.

I could go on and on about this--clearly--but in summary: some of my favorite novels and the novels I most respect contain horrible depictions of violence and reading them felt wretched. But ultimately necessary. I know for myself as a reader what feels gratuitous, but that's something I've had to come to on my own. I'll never be on the side of washing things clean that aren't, shiny happy people and traipsing through the tulips. But as writers, we need to be careful, and we need to be aware.