I've taught Creative Writing in local schools, and have actually been reprimanded for asking the kids to explore their negative emotions. Too often, we make the assumption that kids don't experience the depths of emotions that adults do. Yet some of these kids have experienced divorce, death, and other forms of loss. With no outlet for their emotions, they turn inward.
Poetry is a great outlet, and the therapy it can provide is invaluable.
I know this from my own experience, and I'm going to continue to try to teach this to my students. In the meantime, I'll be coming back to your topic for ideas and support.