I don't see why going through the act of marriage would help a mental illness. Having support, in the form of a significant other, family, friends, etc. can be helpful for mental illness I think. I don't think you need to be married for that. Nothing wrong with getting married either, but getting married and really any relationship will not "cure" someone. Looking for another person to make us better is not really healthy in my opinion. I think with or without bipolar we all have to do the work to be as healthy as possible and then we will be best able to participate in a healthy relationship.