As an adult who has been in the position where I think maybe my parents didn't know what to do for me [though I wasn't necessarily refusing treatment], I would offer this:

I have spoken to many parents who have expressed that they would never do something like call the police on their adult child who is acting violent toward themselves or others, or call an ambulance to have them forcibly assessed if they are not incontrol of their actions of unable to take care of themselves.

I have likewise spoken with parents who feel that it would be unfair to draw very specific clear lines and expectations- such as:
*you can stay here if you are in treatment or have a job or are in school
*you have to [make your own meals, help with X chores, take on this one specific responsiblity]
* saying certain things are specifically unacceptable or certain things are expected, and making clear boundaries and sticking to them

I have to say:
if you are reaching the end of the line, and you have no legal say in your adult child's treatment, there may eventually come a time when you HAVE TO DO ANYTHING YOU CAN.

That must sometimes necessarily include subjecting them to possible involuntary holds at the hospital if they are not pursuing treatment of their own volition or even calling the police on them if necessary- there are times when this is actually your best option to get them treatment, get them into the system.

They may end up in mental health court and sometimes even possibly recieving mandated treatment- and that is SUCKY. I understand this. But eventually, they will be out of mandated treatment and may get that something is going on that they have to reassess.

I don't believe in forced treatment generally, I do believe in wake up calls. I think sometimes as parents drastic measures need to be taken. If that means taking action and getting your child into the mental health court system, or the state hospital system or the adult welfare system- that may be a very difficult but necessary step.

I DO believe in getting your act together and not hurting your loved ones or taking advantage of them. Speaking as an adult child with a mental illness who went through some pretty rough times- if my parents felt they needed to drag me to the ER and that ended up in a hold or I was so out of control they needed to call the police?

I would have been pissed, yeah. But they would have been doing it because they wanted to help me, and they didn't know how. I would have gotten over it.

Not everyone will agree with me, and that's fine.
But it's one point of view I thought should be presented.