17 April 2012

Unhealthful News 213 - More on "addiction", and understanding why NRT does not work

This posts finishes off my recent mini-series on the nature of addiction and related concepts, in the concept of smoking and other tobacco use.  It started with a post about the implications and ethics of a "vaccine" that prevents someone from getting any effect from nicotine.  I then wrote about a new study that provided some interesting insight into the role of addiction in quitting smoking.  In those posts I introduced the notion of second-order preferences (preferences about changing your preferences) and the Chicago School definition of addiction (focused on someone having increasing marginal returns to consumption, rather than the standard diminishing marginal returns), the only candidate for a legitimate scientific definition of "addiction" that exists in the scientific literature so far as I am aware.  I then suggested that second-order preferences offer an alternative definition of addiction, or at least characterize what is often being thought of when the word is used.

I wanted to tie this together a bit in the context of news reports about a new study that shows that use of nicotine replacement therapy causes approximately zero increase in the success of smokers who are trying to quit.  Actually, I am not sure there are such news reports right now, but since there is such a study result every few weeks, I am just going to say there are. 

[It turns out that between the time I wrote the previous sentence and when I posted, a new example came across my desk.  I am not going to bother with details of it because the key point remains that this is a roughly semi-weekly occurrence.  I will note that the authors -- pharma industry flacks -- tried to sell the story that NRT was effective, when their results showed quite the opposite; this is typical, so it is useful to realize that most new studies that claim to have demonstrated effectiveness are really part of the long list that show so little benefit.  Honest researchers would never claim they observed any effect worth mentioning.  For more on the dishonesty of the new study, see this post by Michael Siegel.]

So, what explains the strange combination of "NRT does not help to a measurable degree" with "people are sufficiently convinced that NRT will help that they keep trying it" and "researchers are are unwilling to accept the evidence that it does not help so keep thinking it will be different next time".  Of course, big money has a lot to do with it:  NRT is obscenely profitable, and so like everything from soda to mobile phones, it is heavily advertised with promises that it will improve your life, and most "public health" researchers I know will do any research someone offers them money to do.  But people would not be vulnerable to the advertising, and the news that it does not help would not be so interesting, if there was not some intuition that the products ought to help.  After all, there are no news stories reporting the shocking discovery that, say, wearing your underwear inside-out turns out to not make it more likely you quit smoking.

It seems pretty clear that most would-be quitters use NRT based on the belief that it will fulfill their second-order preference, "I wish I did not want to smoke."  That is how the products are marketed, as a way to fulfill that wish.  But there is an important nuance in the sales pitch:  It talks about some immediate "urge" or temporarily "taking the edge off" because these products are not supposed to be substitutes, but only tools for making the transition to abstinence easier.  (Of course, the pharma is happy to sell most of the product to former smokers who are using it as a harm reduction substitute, just as long as they can keep pretending that is not their main market, but that is another story.)

The nuances of the message and the wish highlight differences between the two candidate definitions for "addiction", and make it clear why it is obvious that NRT will not work.  If the reason someone has the characteristics "chooses to smoke" and "believes he would rather not smoke" is because it is too tempting to relapse before getting through some transition, then NRT or something with similar properties will help.  NRT is designed to lower that supposedly irresistible high marginal return that results from addiction (in the Chicago School sense of the term) until a few days of abstinence lowers it.  (Arguably the products are woefully bad at providing even this benefit, but that is another story still, so let's ignore that complication for now.)  But then again, most people who are really committed to quitting are quite capable of getting through that transition without aid, at least for smoking and even for the likes of heroin.  This was an implication of the Penn State study.  Still, on-label use of NRT can at least theoretically help with this.

So NRT maybe helps the small minority who only keep smoking because they are not able to avoid starting again after a brief period of abstinence (and so benefit from the aid) but are happy to remain abstinent once they get there (really were motivated by an Chicago School addiction).

But for many among that minority (in the West) of people who smoke, the combination of characteristics "chooses to smoke" and "believes he would rather not smoke" is something different entirely.  It really represents a realization that, all else equal, not smoking would be better, but not all else is equal.  In particular, such individuals have substantially higher utility (econ-speak for "are better off") when smoking compared to not in the medium term.  By "medium" I refer to the period that is longer than just the short weaning off period, but for which some resulting serious health problem has not occurred yet, and so is only a possibility.  For them, there is no reason to expect that NRT would help in quitting, unless it was used as a long-term substitute.  The reason they smoke again after being abstinent is not some failure to escape the short-term high marginal utility, but because of the assessment "I would be better off smoking again".  Perhaps this assessment is often made without fully considering the consequences, but often it is made in fully recognition of the health risks.  (I suspect it is seldom made with the realization that low-risk substitutes that are better nicotine source than NRT -- smokeless tobacco and electronic cigarettes -- offer the best of both worlds, but that it yet another story.)

In other words, if we use the word "addiction" to describe this phenomenon, it is not the Chicago School definition.  The apparent difference between "willing to pay the price to consume something" and "addicted to it" is the second-order preference "I would prefer to not be willing to pay the price to consume it".  That creates the interesting situation, wherein anyone who prefers to smoke and says "I am ok with my preferences/choice" is not addicted, whereas if they change their mind about that, they are.  It also creates a situation where the dedicated quitter must either alter his preferences (as with the vaccine, that leave you no better off when using nicotine as compared to not) or forever fight them.

The makers of NRT (and their subsidiaries in government, clinical medicine, and "charities") try to sell people on the idea that NRT will adjust their first-order preferences to better conform to their second-order preferences.  Perhaps it sort of does that in the very short run.  But it does nothing to change a person from someone who benefits substantially from nicotine to one who does not.  Medium term preferences are not changed.  Since the ANTZ who dominate the discourse like to pretend that no one benefits substantially from nicotine, and NRT merchants are happy to play along with this, understanding of this fundamental phenomenon is rare.

If research on smoking cessation was a science, rather than being a marketing and political activity, the overwhelming evidence that NRT does not work would have led to the rejection of a hypothesis.  The hypothesis about behavior that leads to the conclusion that NRT will be helpful is something a bit more general than the Chicago School notion, though it encompasses it -- something along the lines of "people only do this because they cannot break themselves free of it, so something that aids in that breaking free should lead to substantial quitting."  But lots of people start again after a successful break, so obviously that story does not explain everyone, and indeed near-uselessness of all short-term aids suggests that it explains only a very few current smokers.

Having proposed it as a definition, I will conclude by saying that I think a definition of addiction that is based on second-order preferences is a lousy one.  It seems to be what a lot of people mean when they use the term, but a phenomenon whose existence is determined by what someone wishes is not a very robust one.  So we return to the situation where the term, as generally used, is just noise, and the intriguing possibility that to the extent that it is well-defined, it is the addicted smokers that are most likely to successfully quit.

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