Don't say it is beyond doctors, there is always hope. There are many new medications and therapies that you can try. Of course, you have to get your wife to recognise that she has a problem and agree to go to a doctor.
But that is not what I meant. Sometimes as women grow older their bodies change, and this can cause a hormonal imbalance that causes mood swings. I don't know how old you guys are, or what your situation is, but it is possible that your wife is depressed over something, and not bi-polar. I think that the first thing you should do is talk to a doctor, who can tell you more or less if your wife's behaviour is close to that of someone with bipolar disorder (in many cases it is hard to diagnose).
Today there is much less of a stigma attached to bipolar disorder, and there is absolutely nothing wrong with getting some help from a professional.
I don't think we're in the same time zone, so IM may be a problem, but you can always send me a private message via Yedda (click on my buddy icon, next to this post, and on my profile page there is an option for sending a private message).
