Are You Depressed or Just Really Sad?

WaPo reports that some researchers think that depression is over-diagnosed: http://www.washingtonpost.com/wp-dyn/content/article/2007/04/02/AR2007040201693.html?hpid=topnews

Some folks are diagnosed as depressed when they are simply “sad”. How would you be able to tell if you were depressed and should take medication or that you are sad and need to get over it with supportive counseling and the passage of time? You are supposed to be sad after a tragedy, say the death of a loved one or a divorce or job loss, but who is to say how sad you ought to be and how long your sadness should persist? Psychiatrists, that’s who! They aim to be the “arbiters of normality”, and they don’t like it when sufferers and their regular doctors throw meds at depression and anxiety when they haven’t seen a specialist. Counseling sessions are a must. Otherwise, psychiatrists will not be as rich as they could be.

I reckon I know when I’m “just” sad and when I’m not right in the head, and I don’t need to be vetted by a shrink to get meds. Moreover, even if I were just sad, it should be up to me whether I want to use meds to decrease my suffering.

In a different world my melancholy disposition might not be triggered so much, so you might say that the totality of circumstances (society, politics, etc) is making me and other depressed people sadder than we might be in a world organized to accommodate our brain chemistry. Is our brain chemistry out of whack, or is the world?