I feel like I remember once you saying you were nervous about delving into Cassie's issues, or some of them, too much because you weren't sure you would handle them right or... Something I don't remember MAYBE I DREAMT IT.

I think you should do what you're comfortable with, of course, but if you at all want to, I encourage you to go for it! You are a very tactful person, and so I'm sure you'd do your research and be tasteful with it.

TL;DR: Don't be afraid to get deep and dark if it's something you are comfortable doing!