Well, we only got to see part of it. We don't really know what happened over the course of 4 months. *cough*Persephone*cough*. I think the trauma comes from the fact that she was utterly powerless in that situation. She couldn't escape and she couldn't even kill the guy who was keeping her prisoner. No victories. Which I imagine made her feel too much like how she did as a child, and that's sort of where the trauma really comes from... my opinion.