Thanks Fallenangelina. And I don't disagree with the comment (if it is as you interpreted it) at all. But I would say that, in my experience, conventional thinking kind of gets thrown out the window once substances are involved. There is a certain insanity when it comes to alcoholism or any other addiction. I was with my ex partner for years before he became addicted, and found him to be basically honest. But once the binge drinking and cocaine started, he lied like nothing I have ever encountered, before or since. Totally senseless and unnecessary lies. Mainly geared toward manipulating me to take care of things that, as an adult, he should have been responsible for. And of course I did this, since I loved him, I had money, and I kept hoping that he would become the man again that he used to be.
Several rehabs, relapses, and many thousands of dollars later, I left him. Now, 3 years have passed, part of which he spent in prison after being involved in a deadly accident while under the influence. He is still drinking and using. And not the least bit interested in stopping. I've moved on. I'm very thankful I was able to let go, and that it is not my problem anymore.
One could make plausible arguments on both sides as to whether the substances are the cause of this insane behavior or the symptoms of some underlying pathology. But no one should ever underestimate how bad things can get, or how much of our own lives we can lose dealing with the behavior of an addict.
Being wrapped up in monitoring use of a substance is pointless. If we know they're using, then we know. No point in monitoring.
But expecting that they will come to realize that they need to stop, or that there is some medical or therapeutic cure, or that they will be able to EVER share anything in an honest way is a risky proposition. Some do. But many don't.