That said, this is also true of heroin addiction. It is highly related to other, often social, malaises. This has been experimentally proven in rodents. Lonely, unhappy rodents are far more addiction prone. It has been observed in people too, notably the vietnam war example.

I don't even think there is a common treatment for alcoholism anymore that doesn't relate to "underlying" issues. AA, and related group therapies are all about creating a supportive community. Social isolation is a major factor in addiction.

That's kind of what I meant. These hard lines don't exist, and I think many that do exist for research purposes. Hard to study something that isn't discreetly defined. Physical withdrawal symptoms were once a primary researchers' definition of addiction, even though addicts rarely think of it that way.