With any mental illness something chemically is going on. :P We can argue this all day.

Dx's are ment to help doctors understand and for you to understand. They are meant to put a name on things. Like if you had brown hair and your friend kept buying you blond bobby pins. You had no words to explain that you had brown hair :P so she kept buying you the wrong color of bobby pins. You feel very alone because you have brown hair but can't explain it to anyone... turns out there are more brown hair people then blond but you couldn't tell because there weren't any words!

What you think they mean changes with definition of them. I like labels... because it puts words to things. Maybe wrong words, or mean words but at lest it's a word. It's what you make of it that counts.