Hey,
Thats a nice take on the social factors of addiction. Another factor worth mentioning though are the effects of social defeat, which is also a serious health risk. This goes back to learned helplessness models, where animals such as mice and dogs were conditioned to accept electric shocks. If you exposed them long enough, the animals would learn that avoiding bad circumstances was futile. In a similar sense, addicts may learn that they will always be an addict due to the stigmas in their envoironment.
Also do you know the rat park experiments conducted by Bruce Alexander?