Well prolonged stress (and what's more stressful than being abused!) can surpress the immune system and effect aspects of development and ability to learn so that could have a knock on effect on all kinds of health problems.

We often can't be sure with a lot of things if they would have happened anyway or not but I'm certain it doesn't help even with things that aren't actually CAUSED by it.

I also wanted to say on the subject of ME - I have ME too and have known many many survivors who have got that or fibro which is very similar. I'm almost certain it can be connected somehow.