Lamictal acts more like an anti-depressant that doesn't trigger mania than an actual mood stabilizer. Lamictal isn't an anti-mania drug, so I don't think it would prevent hypomania if you added an anti-depressant. I'm not a psychiatrist, but one of my closest loved ones takes lamictal, so I've done a lot of research on it. I do know that said loved one felt pretty dulled for a while, but felt a lot better when he reduced his dose, so maybe that's an option worth discussing.