I say tell them if you are close with them, but I say it for a different reason. When your qualifier is an addict, it can be a lonely road. For myself, when I began to tell the truth about my XAH's addiction, it gained ME a support system I desperately needed. He got mad, but at that point I was beyond caring. A boundary I created for myself was that I would be honest going forward to our families and friends, I needed that.