"You did not cause it, you cannot control it, and you cannot cure it."
This is such a good reminder for those of us with drug addicted children. I also feel I "caused his issues" but I have a daughter who is a fine upstanding member of society and I paid less attention to her as a child, than my son with his asthma and anxiety.
There's no saying what the cause is for addiction. I let my son know he is loved and allow him the dignity of his journey, knowing full well all the bad news his choices can lead to.
I have to keep working on myself and enjoying the life in front of me and not giving into worry and obsession. He's in God's hands.