My SIL was diagnosed with bipolar about 14 years ago. She was always very hyper and found it difficult to keep a job. When she was told by her gynocologist that she only had 2% chance of having children (after TTC for a couple of years) she became more and more difficult to be with.
She was very high, spent hundreds of pounds on things that she could not afford, decided to go and visit friends in a town 3 hours away so that DH and I had to go down and pick her up as her friends did not want her to drive home. It all came to a head when she ordered a new BMW. She had to be sectioned. I always felt that the gynie was responsible for the outbreak, this is probably not true but it was very difficult for her to come to terms with. I know that it is inheritary but it seemes as if the infertility set her off, iyswim.
After that she had ups and downs, staying reasonably stable and then she fell pregnant (2%chance, my ar**e!)
When she is low, she is easier to get on with, because she isn't doing "crazy" things and because she can function and appear to be a normal, if quiet person. It is terrible to say, but for her family it is almost better when she is like this. Saying that, I do recall her being so subdued and quiet at our wedding, not like her normal self at all.
She is on medication, and when she got pregnant again 4 years after the birth of her DD, she came off the meds. Not long after her DS was born she had her second very manic phase, leaving her month old son with her mother and goign out on the town, ordering an expensive mobile phone... Again she was sectioned and spent some weeks in hospital.
That was the last time that it was so bad, her DS is now 9 and she has ups and downs but never so extreme as these two episodes. It is very difficult for her family as they are on the look out for signs of a high phase, MIL gets upset if SIL has her hair restyled and dyed, as she did that prior to her 2 extreme episodes.
She was very lucky to have a very supportive family, especially her DH who has stuck with her through all her problems. She also had Non-Hodgkins 2 years ago and coped really well with the chemo etc.
She goes to see her doc every 4 weeks and gets an implant (I am not sure what meds she is on at the moment) and has a little chat with her therapist.
She has been stabel for a long time, it is possible to live with this disease, but it is really important to remember (and to tell your family and friends) that it is a disease , it is not a case of pulling yourself together.
Interesting to read Zippi's advice, seems like PILs are doing the right thing, they often take the DCs so that SIL does not get too stressed. I sometimes get annoyed with SIL for being so lazy, this thread has made me realise that perhaps it is her way of keeping her condition under control.
I hope that you can find a way to convince your DH to see a GP or therapist. SIL was very reluctant to see a therapist in her high phases, she told me afterwards that she did not want it to end. She also directed a lot of her anger and frustration onto one person, at times her DH, sometimes at PIL. Her anger was irrational, but it was still very hurtful for those concerned.