Well said. Dysfunction is all about personal choices. Many people are able to deal with grief over the loss of parents without becoming addicted to drugs.
I would say it’s very much about personal choices, but not 100%. Some of it is about environment. For example, if I wanted to become addicted to meth or heroin, I wouldn’t know where to begin.
My family has some issues with alcohol use and smoking-related illness, but no association at all with drug use, and that’s over several generations and an array of in-laws, cousins, etc.