Nature of addiction: Mental obsession, physical allergy

Bearing in mind the discussion that arose after a recent post (Seven MORE deadly sins), I would like to carry that on in this blog, thinking about the nature of addiction.
This is a debate that is even had among drug and alcohol professionals, and rages among addicts themselves. Is an addiction a series of poor choices or an illness? How much personal control does an addict have over their using and, by extension, any problems they have in their lives? Logic dictates that if people would just make better choices, they wouldn’t have the problems they have. However, it is NOT that simple for an addict. That is a critical point in the addiction debate. The whole point of addiction is that it can’t be controlled.
It is hard for me to wrap my head around because I’m not an addict. I can say, “No thank you, I’ve had enough.” My clients can’t. I think it’s hard for me to conceive because of the complexity of addiction. There is spiritual and emotional element of addiction – as well as the physical - that is completely ignored in “normal” society. We don’t talk about healthy ways to deal with shame or anger in our day to day lives, for example, and these are two critical interpersonal spiritual issues that cause a lot of problems for addicts with whom I work.
A lot of people I love are addicts, and I have seen these people, when they’re using, become completely different people! It is really hard to describe, dear reader. It’s scary and sad. They have selfishness, self-centeredness, and a complete and total inability to see the truth that is not present in them when they are clean and sober. (I’m not gonna lie, that is infinitely frustrating as well.)
In my opinion, addiction is a mix of choice and compulsion. One can choose whether or not they pick up. Once they do, however, the choice is no longer theirs, the drug takes control. It becomes, as 12-step wisdom says, a “mental obsession, a physical allergy.”