It can be difficult to distinguish "normal" dark creativity from something of a more clinical concern, especially when you add the intensity and asynchronous development of a gifted child. Even so, many of the creative geniuses of the past--say, Edgar Allan Poe--were, in fact, mentally ill.
In my day, we had "artsy death chicks". These days we have "goths". It does seem to me that pop culture in the last ten years has celebrated the darker side of art more than it did when I was a kid. However, I now live in Hawaii, and goths really stick out here. They are probably more likely to placed on a fast track to fairly intensive services here than elsewhere.
I'm thinking of the school counselors, behavior specialists, clinical psychologists, and school psychologists I've worked with in our district over the years. Not knowing the personalities and philosophies within your school district, I would ask the counselor or principal--in your shoes--if you could have a consultation with a school psychologist about this issue. I imagine they would be most likely to know about both the attributes of gifted students and some screening instruments which could help them determine if we are actually looking at a mood disorder.
