Unfortunately, I have too much experience on this subject. Without compromising privacy of family members, I will say that the "collateral damage" to family is much more severe than people without this problem could ever realize. Part of the reason that this is such a hidden problem is because the mainstream focus is on the addict - and the reason the focus is on the addict is because the addict is a source of revenue for the rehab industry.
When you have a family member who is an addict, initially, you are in crisis mode. Because you are dealing with someone under the influence of a substance, by definition, you cannot deal with this person rationally. They might show up on your doorstep, for instance, at midnight, or in a heavy rainstorm (have had both of these experiences, plus many others happen). They are "out-of-it" - what do you do? It is a HORRIBLE dilemma for a loving family member.
There are meetings with family members, brainstorming "what to do." The addicted person is incapacitated and cannot participate. The person may be taken to a rehab facility and the facility might take them in - at great expense. The first time, the family might think the person "will be cured" in 30 days! The family might travel great distances to attend "family days" (which focus mainly on the addict and what the family MUST do to support them). There is no support for the family members - they are told to "Go to Alanon" - meanwhile, Alanon is not for everyone (the subject of a later blog post, perhaps.)
The cycle of crisis, rehab, sober living, relapse - rinse and repeat - can go on for years. The family is expected to always be supportive. There is little to no concern on the part of rehab facilities for the actual impact on families. They just rake in the money and tell you to "go to Alanon."
Naturally, a toll is taken on family members - there are rifts in the family caused by constant stress - there is blame thrown - "so-and-so caused the problem" or is making it worse. People get sick from the constant stress. Meanwhile, the problem continues with no end in sight.
If you love the addict, you WILL be affected by their decisions and their well-being or lack of such. No matter how many times you are told to "detach," you know that in love there is attachment - ironically there is an entire movement of "Attachment Parenting," where people are taught the virtues of various ways to enhance parent/child/sibling attachment/bonding. If you are "attached" through love, then you cannot detach on a whim. Bonding does not work that way. There is no surgical removal of love - it is there or it's not there. If you love someone, you ARE attached to them. So in cases of chronic relapse, after your health has been compromised perhaps, you must deliberately detach (going against nature) as much as is possible by consciously putting your health and well-being above all else. This is often done by withdrawing from family and severing or severely limiting family relationships, and tending to your own needs.