Is addiction voluntary?

I'm pretty fascinated by this new book on addiction. The author (Gene Hyman), a psychologist and professor at BC (I think), argues that addiction is voluntary. I don't have anything profound to say about the matter, but I think that his framing of the issue is interesting.

He begins by pointing out that most addicts are ex-addicts, meaning that roughly 75% of addicts have stopped being addicts, and that among these, most have done so without clinical treatment. So it seems that most people who become addicts stop on their own. And why have they stopped? Heyman's answer: because continuing the addiction became too costly. Whether for financial, health or family reasons, addicts tend to quit when, to put it bluntly, it just ain't worth it anymore.

And yet, Heyman admits that addictive behavior is compulsive. So why call addiction voluntary? Because addictive behavior seems to be for the most part sensitive to the sorts of incentives that guide everyday choices. And this is just what Heyman means by 'voluntary': an action is voluntary not by virtue of its cause (whether by an unfettered will or by some antecedent brain state), but by virtue of its sensitivity to incentives. Schizophrenia, Alzheimer's, bipolar--these are utterly insensitive to costs and incentives, and are thus diseases. But addiction, Heyman argues, for the most part is sensitive to incentives and so is voluntary. Thus, it is not a disease. This conclusion seems to follow even if we acknowledge the truth that tendencies for addiction are heritable. (Many critics of Heyman seem to ignore this point, not realizing that his definition of 'voluntary' is consistent with voluntary behavior being both heritable and a function of the brain).

So my first question: Why can't diseases sometimes be voluntary? Here's something a philosopher might say: addiction is voluntary, but not free. Addictive behavior is the effect of first-order decisions, which, like all voluntary decisions (which is to say, decisions per se), are sensitive to costs and benefits and follow a preference structure (utility function). But the addict, usually, is not very happy with the choices s/he makes, and to this extent, is not free. Can we allow voluntary but unfree diseases? If so, would this neutralize the annoyance many people feel towards Heyman's thesis? (Incidentally, we might already have a name for such 'voluntary diseases,' viz., character flaw.)

A second question: Why does the label matter so much? There has been a lot of mean ink directed towards Heyman, often from recovering addicts. One obvious reason is that we as a community have decided that we don't want to blame addicts for their actions. It's important that we continue to refer to addictive behavior as a disease because it's important that we inoculate the addict against moral opprobrium and judgment. But why is that important? Because it's not effective. Expressing moral disapproval is not very likely change an addicts behavior.

And so a third question: What kind of costly, self-harming practices wouldn't be better influenced by treating them more like addictions than like moral choices? Deceit, thievery, infidelity, cowardice, exploitation--these sorts of behaviors are almost always in the end self-destructive, and so why not treat them also like diseases? The answer surely has something to do with the fact that by labeling something as a disease we undercut our right to moral indignation, which is usually a peculiarly pleasurable feeling, and therefore one which we will usually protect.

UPDATE: This is amusing. From Sunday's NYT Magazine:

"Our national weight problem brings huge costs, both medical and economic. Yet our anti-obesity efforts have none of the urgency of our antismoking efforts. “We should declare obesity a disease and say we’re going to help you get over it,” Cosgrove said.

Indeed. This article tells a story about the efforts to label alcoholism as a disease. Apparently, after the repeal of prohibition, a predictable surge in alcoholism followed. But alcoholics were told that this was a moral failing, and so was accompanied by a surge in just the same sorts of moralizing forces that had been responsible for prohibition in the first place. The doctors on the Research Council on the Problem of Alcohol needed to get convince the people to send alcoholics their way, and realized that calling it a disease was a good way to accomplish that. Notice that Dr. Cosgrove (from the Cleveland Clinic) in the quote above is advancing the same sort of reasoning: it's not that we care particularly whether or not alcoholism/obesity is a disease, we just observe that by calling it a disease we help to effect better results.