Wow, Kimmie, that is a lot of information that you shared.
One thing that I have not seen mentioned, however, is a biological mother. Is she in the the picture at all?

You have been involved with this child since she was 4 or 5, as far as I can tell. And I have walked in your shoes, too. My late husband (he died in 1993) had a passle of children from age 2 on up when I married him. And of course, since I was not "their mother" they did not think they had to listen to me. Over time, that got better... but when there was conflict, I always deferred to their dad. It was so much easier that way, and actually paved the way for good relations between the kids and me. Remember, too, that there is a special bond between dads and thier daughters- the same as there is between mothers and sons. Don't ask me why. There just is.

So, your new behavior of asking and validating without criticizing or making suggestions is very good. It lets HIM be the primary decision maker about his own child, good or bad.

But I also know it is tough, especially if he seems ill equipped to be making good decisions. Men, as far as I have discerned, tend to be "looser", and less authoritarian than maybe they should be. Adhering to rules seems to be more difficult. Dads seems less able to look at long term consequences of bad behavior, and more forgiving of it. Now I know I will be lambasted for such a comment, but as I said, this is what I have seen and learned from the men that I have had in my life. I am sure that there are plenty of fathers out there who truly look at the "big picture' when it comes to raising children. But a lot of them don't. They look at today, and today only.

As for dealing with the clincially depressed, that is really tough. If they don't see the problem realistically, then it is hard to get appropriate treatment. For them, oftentimes their reality is that "change is too difficult and it's not going to work anyway" and since they don't have the energy to even make small changes, anything big is impossible. It would be nice if they could see the value in "baby steps", but oftentimes they don't.