I am happy to have finally found a type of support group/forum about adult children estrangement, it has not been easy to find resources and/or support. Hoping to get some of that from this online community.

I am actually reaching out to see if I can help a friend who is dealing the estrangement of his now 20 something year old daughter. She has a history of mental health issues, dissociative disorder, which might explain her estrangement? I do not know that much about that disorder - if anyone has any experience and our resources to recommend, please send them my way.

She had been living with her dad and had plans to attend a local community college. Her dad helped her find a place to stay and was in the process of moving in on her own and starting school. Then suddenly no contact with her father. The daughter had reached out to her mom and then checked herself into mental health facility. Because the daughter was over 18, the father was not able to get any information about her, her status, etc. The mother has been uncooperative in sharing any info she has about the daughter and it is possible the daughter has since not been in contact with the mother as well.

What is most challenging about this situation is 2 fold.
1) the abruptness of the estrangement, there was no big fight, no communication as to why there would be no contact moving forward, etc. The daughter & father had has a strong relationship up until this point.
2) not sure how much her mental health has played into this situation? Is she consciously not reaching out to somehow protect herself? or maybe one of her other personalities does not realize that her father exists?

My friend, her father, has been heart broken about this estrangement and didn't see it coming, was given no explanation, no nothing. If she has told him that she needed space and didn't want to have contact, although it would have been difficult to hear, he would at least know that it was a conscious choice.
I am not sure how to support him. I want him to be hopeful but yet want him to be able to move on with his life and dwell on this estrangement. However, that is much easier said than done. He feels that is can not give up on his daughter and is not willing to accept this.
I have tried to say that, unfortunately, it is not his choice. He can not control what she does, he has not means to contact her, I do hope that she reached out one day, but in the meantime, I have tried to tell him he need to focus on himself and his happiness.
He has been unable to do this and for over 4 years this estrangement has been wearing him down.

Anyone have suggestions on how I can support someone going through this. I want him to be hopeful but yet it is possible that there might not be future contact and by holding onto that hope just never lets him move on.

thanks in advance for reading and sharing any thoughts. ...