Why isn't there a disorder for, well, disorder?

I asked a question about OCD, and someone said they were the “opposite of it.” You get the meaning. I don’t mean to diminish from this (oft debilitating) condition or disorder, but rather, to look into something I found curious: it’s called a disorder – the opposite of order, yet we label people who are compulsively clean or neat, but not those who are astoundingly messy, dirty or both. Isn’t that… disorder?