In oppositional defiant disorder, novalis speculated that (some of) the diagnoses in the DSM might be politically motivated. Political, yes, but also cultural. A history of what is/has been considered mental illness would be a fantastic cultural history of the United States. Consider the classification of homosexuality (or any alter sexuality) as a disease (this has been removed from the book in recent versions), or the (relatively) recent explosion of children's behaviors (such as oppositional defiant disorder, but also certain cases of ADD, childhood depression, etc.) Culturally, children are a very problematic group right now. Their struggles to live in a world (or worlds) with conflicting messages and structures are biologized and pathologized because this moves it into the realm of science and experts, and out of the realm of human interaction and responsibility, which is scanty.

This is my opinion, of course, and does not imply that the DSM does not hold valid or useful information. I just believe that there are certain things that would not be best treated as a disease, but as part of either a process toward identity, a struggle with a greater fucked-up society, or an identity in itself.