I don't see it being over-diagnosed or under-diagnosed particularly - I think it's quite a healthy balance (where I live, at least). The only issue I really have is that I see a lot of people self-diagnosing before blaming everything they do wrong on the disorder they most likely don't actually have. For some reason, mental illness seems to have become "trendy" among the adolescent population. When I was diagnosed, I was an outcast (only a few years ago) yet people claiming to be Bipolar now tend to be seen as "quirky".

It annoys me.