If the person is an adult, then there is little you can do to find out if they are seeing a doctor or not. That doesn't mean you have to put up with bad behavior. Set boundaries for what is acceptable to you and stick to them. You can make the offer to help if the person is willing to let you, but you can not control the person. I know if it difficult and I would recommend that you seek out a therapist for yourself to help you handle the situation in a healthy manner for yourself. A therapist can help you find a way to reach out with concern for the other person in a way that might allow them to open up about what s/he is going through, while at the same time giving you and the rest of your family strategies to deal with the situation.

My husband has bp. His behavior is often unacceptable because of it. I have set boundaries with him (when he was stable) and stuck to them. It is has been healthier for both of us. If he becomes verbally abusive then he doesn't get the pleasure of my company. The subtleties and complexity of the arrangement it hard to put in to a short reply properly. I comes down to this, just because someone is sick, it does not mean you have to tolerate bad behavior.

You are in a difficult position. There is hope.

thank you very much for responding chemnut
I think boundaries are absolutely needed!
I do know the bp is seeing a psychiatrist and therapist too. How is it possible with this help that bp NEVER any apologizes for outrageous behavior?? The severe harm to my family is the only reason I try to find some answers to this. Getting no information has pushed me as far away as possible but bp is still effecting the family in a negative way. Do consequences effect them at all? Not from what I have seen.
I appreciate any thoughts.

From what I've seen, whether or not a person acknowledges and/or apologizes for the bad behavior that can result from the bp depends on the person. My husband does apologize when he is stable. When he is in the middle of an episode I don't get any sort of apology and he often expresses how he feels his behavior is warranted (which it isn't most of the time). Thankfully, when the episode has passed, he acknowledges my pain and always encourages me to do what I need to do to be mentally healthy. He supports my seeing a therapist and does not take my distancing myself personally (much like I don't take much of what he does and says when in an episode personally). It has taken us a lot of time and effort to get to where we are. There were lots of mistakes and hurt along the way.

To contrast that a little bit, I had a father that never apologized for anything. No matter how much he verbally hurt me (thankfully, he was not physically abusive), it was ALWAYS my fault. No mater the evidence to the contrary, I was ALWAYS wrong and he was right. Consequences (what few I could follow through on) had no effect on him. He left deep, deep scars on me, deeper than any my husband's bp have.

It is probably not the bp (although the bp maybe aiding it) that is responsible for how your loved one is acting. And while therapist can encourage someone to take responsibility for her/his actions, they can not force the person. My father went to counseling, didn't change his behavior at all. The best you can do is set healthy boundaries for yourself, be open to person if they do come an apologize and seek your help, and research bp as much as you can so you can separate out what is caused by the bp and what is caused by personality. You might want to do a little research into narcissistic personalities. I don't know that it applies, but you might find something useful.

What you are going through is not fair or just. Sometimes it is hard to accept that logic and rules don't apply. One of the best things I read after learning my husband had bp was "Loving Someone with Bipolar Disorder: Understanding and Helping Your Partner" by Julie A. Fast, John D. Preston. In the book, they talk about the "bipolar conversation". It was a light bulb moment for me. I would get so frustrated with conversation I would have with my husband because the logic was off and I could never get him to see it. I started recognizing that when that was happening and that it was a sign the bp was in control. I stopped trying to argue my case in those situations and avoided a lot of hurt and frustration.

Hang in there.