Back to the Deep end of the pool

Lately things have been slipping back to the not-so-good-side. The husband's mood changes are getting more and more frequent and now he's invited his "friend" to hang out at our house. (Short background of "the friend": he's been the husband's best friend for the last ten years of so, he's younger then my husband by about five years, he does not have a job, no car, and still lives at home with his parents. While he does have a good heart, he's not the best "friend" a bipolar person could have) The husband will go through phases with this "friend", he'll talk to him for a while, not talk to him for a while, downright dislike him, and then defend him if I say something negative about him. The husband always calls his friend right before a major manic episode starts, not sure why, but it seems to be a pattern. The two of them will watch weird movies and play video games and just quietly hang out, nothing dramatic, nothing eventful. I would just love to know the connection between this friend and the husband's approaching episodes. It makes me wonder if it's the husband's way of trying to fight off the episode, trying to calm down, relax even. I hate the thought of another episode, the fights it brings, all the tears and resentment that will follow. But, as usual, the change in seasons are approaching, which always guarantees an episode. I wish I could step inside his mind and read the book that makes him tick, maybe then I could figure out how to help him.