Lamictal has helped me with the depressive side of my illness. I'm also on a sub-subtherapeutic dose of Celexa because I can't quite manage without an AD (tried and failed miserably twice). Unfortunately, I also need 2 APs and a benzo to deal with my manic symptoms because they get me into a lot more trouble than depression, even though the latter is much more distressing to me.

Like a PP said, I too have to question a doctor who prescribes an antidepressant alone to someone diagnosed with BP. That's just not done the vast majority of the time, because ADs that are unopposed by mood stabilizers tend to throw people into mania if they are truly bipolar. I'd get a second opinion if I were you.