The family is a system, like a mobile in which everyone is connected and the whole seeks balance. Each individual affects the whole system and the whole system affects each individual. Each person has their place, role, or position in the family. The mobile would shake and get off balance if there is a crisis. The crisis disturbs the balance but in time a new balance settles in.
Some crises are predictable (children starting school or becoming teenagers), some crises are unpredictable (loss of job, moving, divorce, illness, death). All events in the family affect the system's balance, but when you are part of the system, you are partially blind to what is going on. Addiction is a burden that makes the individual less functional. Maybe the addict skips school, does not attend family dinner, and does not get up in the morning. The whole system is off, whether or not the family members know about addiction; each family member is affected.
Often unknowingly, family members try to compensate or "over function" to regain balance. For instance, a parent might "work harder" in the family or on the addict's behalf so that they don't feel the consequences of their use. Parents or siblings might lie to teachers, work, or other family members.
Most siblings feel loyalty to the addict and feel very conflicted between loyalty and the danger that the sibling is in. Often they know much more about drug use than parents. Some siblings resent that parents spend so much energy and money on the addict while their achievements go unnoticed. Some siblings are angry at parents for being too lenient; others view treatment as an overreaction.
All children know how to triangulate their parents for their own benefit. In addition, this ability serves a special purpose of disabling parents and enabling the addiction. Triangulation occurs when a third person gets involved in the relationship between two people. You are being "triangulated" when you are diffusing the tension between two other people.
In most relationships, we seek balance by compensating the other person's "overfunctioning" or "underfunctioning". If my spouse is very emotional and unstable, I feel the need to be rational and in control. If my spouse is a big spender, I feel the need to be very frugal.
John and Mary are engaged and will be married soon. John is very relaxed with money and has never been able to save. He often buys things he can't afford and does not pay bills on time. He has many credit cards and has a balance in each one. Mary, on the other hand, is financially very responsible and started saving for retirement early on. She uses a money management program and is on top of her budget. She is very frugal and rarely uses her credit card. What happens after they put their finances together? What would be the ideal outcome? John becomes more responsible and Mary can relax a little. Why is that unlikely to happen? John has no incentive to change because Mary is already doing everything. Mary can't relax because she is nervous about John's spending and she tightens the reigns even more. Neither one has an incentive to change but both have an incentive to do more of the same and move to opposite ends of spectrum.
The protector and the persecutor operate from two opposing philosophies. The persecutor believes that when there is a problem with your child, more control or punishment will fix it. The protector believes that when there is a problem with your child, more love will fix it. However, addiction is not "fixed" by either method (but these parents do not know that yet). A pattern evolves where parents disagree with each other's approach and overcompensate for it. The protector and blamer might create a close bond with each other while the persecutor becomes the outsider.
Let's say that son gets busted in school for having a small bag of marijuana and a pipe in his backpack. Which parent will he tell about it? (Protector) What will he say? ("It wasn't mine"). What happens next? (Protector defends son, makes excuses, promises to take care of it, blames school, etc.) Why does the protector decide not to tell the persecutor? (She does not want him to lose his temper and get upset). She thinks, "One of these days he's going to have a heart attack," and feels obligated to protect her spouse from such stress. What happens after persecutor finds out? He blames her and the conflict is ready between parents, while addict is off the hook and is probably on his way out to get high.
The persecutor could turn to the protector and say, "I can appreciate that you can be nurturing and show feelings, I need to borrow some of that from you. Will you help me with that?"
The protector could say to the persecutor, "I appreciate your ability to stick with consequences and not cave in. I need more of that spine of yours. Will you help me with that?"