By all means, talk with the transplant coordinator about your medication. It's important for both you and the recipient. It will probably not disqualify you from donating, but you may have to have an additional interview with a psychologist or psychiatrist to evaluate the dangers to you of post-surgical depression. Things don't always go well with transplants, and recipients sometimes do have complications--sometimes serious ones--that can have an emotional impact on donors. Therefore, it's important to have as much support as needed.
I took anti-depressant medication on a consistent basis for a lot of years before I donated. During my donor evaluation, I had to have an interview with the psychiatrist at the hospital where I donated just to make sure I was "in a good place" and that I could, hopefully, emotionally handle any unforeseen complications.
Good luck to you!