Chicory, my mother played a very patient waiting game. However she did insist he get an assessment and any necessary meds. She was not in the room the second time, although she definitely wanted to be. I don't know how many talks she had with him before he agreed, but definitely more than one.
He took the meds. I think she may have laid down the law on that one.
It took him a few years after getting meds to get motivated enough to go to work. 5 years of supporting him completely. Now he pays for most of his own things. He may never be truly independent, but as she is in her late 70's, she likes it that she doesn't live alone, and would probably have had to give up the house, so that is beneficial to both of them.