I must agree with what anvilhead posted. What is the intent of the addict? If they are trying and struggling, that is one thing, but if they are not detachment may be the one thing that saves their lives.
For me, I struggle daily with detaching but give it my best effort as I understand it and do so out of love. My view is that you must understand first how the addict manipulates and then understand that by allowing this behavior to continue, without any effort towards recovery, is actually helping him kill himself. I can't explain to my son that daddy is dead because mommy loved him so much that she couldn't just let him hit bottom once and then come back up, no mommy had to enable him by letting him come back home so that he continued in his addiction until it killed him! This is strictly how I have to look at things in order to understand that for me detachment is the single most loving thing I can do until crack addicted husband decides to get himself clean.
I do hope that this will help you to understand that I would detach from brother, sister, mother anyone that has an addiction because I want no part of helping them to their grave.
My philosophy is there are two ways out - recovery or death. If he isn't going towards recovery, I won't love him to death. Again, this is the only thing that keeps me strong. I have to say that I judge no one for continuing in a relationship unless it is abusive and if children are involved that is my hard line. No ifs ands or butts about it.
Let me also close by saying that when I look at any addict what comes to my mind is.....but by the grace of God, there go I.