Welcome to HealingWell. We're glad you've joined. I hope we can offer some answers or support for you.
It's hard to say what's normal for bipolar because it comes in so many stripes, but your MIL's case sounds especially complicated. The drugs and the depression and bipolar make each other worse, so it's hard to say which came first, in a way. I'm in a similar place with my father who is an alcoholic and has major depression. They treat the alcoholism but it won't go away because of the depression which won't go away because of the alcoholism... You get the picture.
Hearing voices is unusual but not unheard of, but I would definitely mention it to the psych next time she has an appointment. Are you attending appt's with her?
Co-Moderator, Bipolar Forum