I was wondering whether I have ADD or depression?

When I first started getting treatment for how I was feeling - zip concentration, losing things, not able to concentrate even on work, I thought maybe it was ADD, but my Dr. said it sounded like depression (also felt like in a black hole, sad and was isolating myself from the world). She put me on an SSRI and it totally cleared all of my concentration problems - so does that mean it was depression and not ADD?

I think that's a question for your doctor. Depression symptoms can mimic ADD. If you take the depression quiz, a lot of the questions ask about memory, concentration, and decision making. My Pdoc also told me that chronic insomnia can cause a lot of the same problems as ADD. If your depression causes loss of sleep, then you're probably going to have the concentration and memory problems that come along with it.

Yes, I was definately not sleeping, and still am sleeping so-so but the anti-dep's have helped with that. It's amazing how completely my concentration problems disappeared.