I'm not a meds expert, so I can't address the technical parts of your questions. But in my experience, treating depression effectively can often help ADD symptoms as well. Have you had a formal evaluation for ADD? If not, perhaps your doctor would be more amenable to treating your ADD symptoms if he had the diagnosis from a colleague. Also, don't rule out therapy for both depression and ADD. Both can respond to behavioral interventions, too, and this approach works well with meds.

Good luck!

gg