I think, if you're talking about an addict, we have no power to help them. We can only help ourselves, maybe by doing that we show them how to help themselves? I put a question mark because I really don't know to be honest.
For the record my mother let my brother live with them, paid his bills and was a big part of the drama. It didn't stop him drinking, but i don't know it would have stopped him if she'd done the opposite.
I dunno if anything means you're codependant or not, if i sneeze do I have a cold?
I decided I needed to sort myself out, not for anyone else, for me. It took a long time to get to the point where I realised I needed to sort me out though.