Wouldn't that apply with any destructive behavior? Addiction presents a different issue but abuse (mental,physical,verbal), infidelity, financial irresponsiblity, poor parenting, all would require the behavior to be addressed as well regardless of the self improvment required.
Ummm ... yeah & Doh!
If you don't address the behavior, then you are enabling it. Without good boundaries, you are... (and I hate to use an over-used and over-applied term, but...) codependent.
If somebody doesn't respect healthy boundaries, it's OK to tell them that's just plain wrong, and if it's continual, then it's OK to remove yourself from the situation.
M-47,W-40,No kids D-filed 5/27/2010 Piecing - 10/21/2010 -=Soon to be banned=-