Controversy about addiction over the last few decades has centered on the virtues and drawbacks of the disease model: Is addiction justly portrayed as akin to other mental illnesses such as depression, obsessive compulsive disorder and schizophrenia, and perhaps even physical illness? Or does the disease model conceal important dissimilarities to these conditions, and therefore compromise our efforts to treat and prevent addiction? The current consensus in the addictions establishment, for instance at the National Institute on Drug Abuse (NIDA), strongly favors the disease model. NIDA, other agencies, and addiction specialists have worked hard to promote the idea that “Addiction is a chronic disease similar to other chronic diseases such as type II diabetes, cancer, and cardiovascular disease” (see here (link is external)). Since it’s often seen as a moral failing, declaring addiction a disease has helped to destigmatize addicts and encourage parity (link is external) for addictions treatment under medical insurance. This is all to the good, even if the conception of addiction driving these trends is contested.

Gene Heyman’s well-written and persuasive book, Addiction: A Disorder of Choice, (link is external) takes dead aim at the disease model, so will likely not be welcomed by its supporters. But whatever side of the debate they’re on, anyone interested in the nature of addiction and choice should read it. Heyman, a psychologist with appointments at Harvard and Boston College, presents an eye-opening and empirically grounded theory of voluntary behavior that goes a long way toward explaining addiction, not as a disease, but as choice-making gone bad. His analysis adds substantially to the growing literature in behavioral economics that shows we are not optimally rational maximizers of our own self-interest. Addiction, it turns out, is simply one rather vivid manifestation of a basic feature of voluntary action: judged from the standpoint of an ideal consumer taking a long-term view of her choices, we tend to overconsume our immediate preferences, and in so doing undermine our net self-interest over the long haul. Drugs, including alcohol, are very good subverters of ideal, globally informed choice-making, so addiction properly understood is a paradigm disorder of choice, of voluntary behavior. Since diseases as commonly defined don’t primarily hinge on choices, addiction doesn’t qualify as a disease.

Because it presents choice-making as a function of controlling contingencies, not free will (p. 114), Heyman’s theory does at least as much to destigmatize addiction as the disease model, while staying true to its actual behavioral dynamics. Those advocating for addicts need not deny the obvious: that addiction is unlike illnesses by virtue of the role voluntary behavior plays in becoming addicted, in obtaining drugs, and in ceasing to use them. As Heyman points out, even though people choose to use drugs and alcohol, no one chooses to become an addict. Moreover, he emphasizes that addicts can’t simply choose to quit without a change in the circumstances, biological and environmental, that control their choices. He is not, therefore, a stern moralizer bent on punishment, but a clear-thinking, humane psychologist wanting to apply our best behavioral science to the treatment and prevention of addiction. No one should pre-judge this book based on preconceptions about what questioning the disease model might entail.

Is addiction a disease?

Heyman starts out with a concise overview of the recent social and conceptual history of addiction in the US, showing that the disease model dates back to the late 1700’s, as doctors sought to help those who became addicted to alcohol, opium and widely available opiate and cocaine-based “patent medicines.” The medical approach was eventually overshadowed by the criminalization of drug use by the 1914 Harrison Act, abetted by the public perception that addicts, far from being victims of compulsive drug use, simply preferred intoxication to staying sober. Thus arose the most telling socially constructed distinction between addiction and other mental disorders: “addiction remains the only psychiatric syndrome whose symptoms are illegal and automatically trigger costly punishments, which sometimes include time behind bars” (p. 11).

This raises the question of whether those that use drugs, addicted or not, deserve punishment, and to what extent it serves to reduce substance abuse or simply drive it underground. Heyman is skeptical: “If time in jail turns out not to increase the relative value of activities that compete with drug use, then the criminal justice approach will have little lasting influence.” But he is also skeptical of the outright medicalization of addiction, saying “if addiction differs in significant ways from chronic disease, then treatment strategies that are successful with chronic disease are unlikely to be as successful with addiction” (p. 17).

In the context of describing drug use over the ages, especially of opiates, Heyman shows that the propensity for abuse and addiction depends on social and situational factors, individual differences, and newly contrived and more efficient routes of administration (e.g., smoking or injecting heroin as opposed to drinking opium tea). This distinguishes addiction from physical diseases as well as the syndromes described in the Diagnostic and Statistical Manual of Mental Disorders (link is external) (DSM), most of which are not sensitive to cultural trends or technical innovations. He presents compelling accounts of the course of addiction by addicts themselves, some of whom manage to quit drugs without treatment. They do so primarily because behavioral demands that arise in adulthood – keeping one’s job, keeping one’s friends, being a good mother – eventually reduce the subjective value of drug consumption compared to non-drug alternatives. This suggests that addiction shouldn’t be equated with illnesses whose inception, progression and cure are largely independent of voluntary choices (except insofar as the cure of any disease necessarily involves a person’s choice to pursue treatment). Heyman also presents evidence from surveys that many addicts stop using or cut back to non-addictive levels of use on their own. This suggests that “addiction is not chronic. Indeed, it could be said that it is just the opposite: self-limiting…a self-correcting disorder” (p. 76).

For addiction specialists and clinicians who’ve seen all too many relapses, this claim will sound outlandish. But this is because they encounter mostly addicts in treatment, who Heyman argues have higher rates of co-morbid conditions, physical and/or mental. Such “dually diagnosed” individuals, because they are overall less functional, have a harder time quitting and are more prone to relapse. The conception of addiction as a chronic, relapsing disease is thus driven by a biased picture of the natural course of addiction. Heyman believes that many clinicians are unaware of his findings, so his book is intended to wake them from their dogmatic slumbers.

Local vs. global choice

It’s likely that most clinicians and laypersons are also unaware of the fundamental dynamics of voluntary behavior Heyman brings to light, dynamics that help explain addiction itself. Most of us, when faced with a choice among options with differing subjective values, will often choose the most immediately rewarding alternative. Heyman’s prosaic example is choosing between Chinese and Italian restaurants, where it’s stipulated you somewhat prefer Chinese food. Say you go out to eat every night, what’s the best course of action? When asked about this, most folks follow what Heyman calls local choice: they say they’d choose whichever type of food is most appealing on any given night. For instance, after eating Chinese a few times, you switch to Italian because you want a change of diet, then go back to Chinese as your whim dictates. But a minority of folks reason differently, following what Heyman calls global choice: they consider a series of meals taken as a group, looking to maximize their gastronomic satisfaction from that perspective instead of on a local, night-to-night basis. It turns out that for a series of meals taken as a group, the equilibrium (the ratio of meals) reached on the basis of global choice actually produces more net satisfaction than the equilibrium based on local choice. By having a few more Italian meals than you would have chosen by local choice, you end up increasing the value of the somewhat less frequent Chinese meals. This increase in value ends up giving you overall more value over a series of meals. The very interesting general lesson is that we increase overall satisfaction by sometimes consuming less of what we prefer at the current moment of choice. To maximize reward, we should rationally take the global perspective on choice, not the local; we should at least sometimes abstain from our immediate preference.

But as Heyman points out, and he has equations and graphs to back it up, we often fail to be rational in this regard. Most of us, most of the time, end up closer to the local rather than global equilibrium. Voluntary behavior is most directly shaped by anticipating immediate rewards while ignoring deferred costs, and thus is vulnerable to short-term bias. Unless constrained by taking the global perspective, Heyman argues, choices are often inherently suboptimal as judged from that perspective. This is the inherent “dark side” of voluntary behavior which helps explain the grip of addiction and the fallout from our instant gratification consumer culture, including obesity. Overconsumption of preferred alternatives results from the very nature of voluntary action, it isn’t a behavioral aberration. It’s fair to say that most of us, perhaps even some economists,[1] need educating on this score, which makes Heyman’s book of considerable importance.

The power of drugs

Drugs can be far more immediately rewarding than non-drug alternatives, depending on what those alternatives are (hence the importance of situational factors in explaining addiction), so drugs can be strongly preferred from the perspective of local choice: “The distinguishing properties of addictive substances are that they undermine competing rewards, they provide immediate pleasure but delayed, hard-to-detect costs, they are not directly satiating, and they are intoxicating” (p. 152). Heyman argues that even as drug use itself becomes less rewarding as the result of neuro-adaptation (habituation, tolerance), using drugs also drives down the value of non-drug alternatives.[2] This means that unless something comes along to change the balance of rewards, on any given day drug use for the addict is always more immediately rewarding than abstinence. This gives power to the local choice perspective, and determines that the likely choice will be drugs, not non-drug alternatives. Moreover, the effects of drugs – intoxication and the resulting (usually temporary) cognitive and motivational impairment – make it more difficult to take the global choice perspective, which requires weighing deferred costs and benefits. Conclusion: even though addictive drug use involves voluntary choice, the balance of rewards strongly influences the addict to choose drugs, and to favor local choice at the expense of his long-term self-interest, an interest that depends crucially on choosing non-drug alternatives.

Heyman explains that all this has a completely physical basis in the brain, where neural networks assess competing value propositions. Remarkably enough, these networks translate such disparate inputs as abstract social norms, the demands of a job, and getting high into a common neural language or computation (take your pick of metaphors), and then produce a behavioral solution, a choice. By virtue of their powerful effects on the brain’s reward detection centers, drugs often outcompete other inputs, thus driving the choice toward further drug use. The physicalist understanding of choice-making underscores the fact that there’s no undetermined, immaterial chooser independent of the brain and body that could intervene and make a better choice. Addicts, like the rest of us, just are their brains and bodies, located in a particular environment, and their behavior is explicable as a complex function of their situation, internal and external. There’s no reason to think that were we in their situation, with a similar personal history and biological endowment, we’d be doing anything different. Drugs would have us in their grip just as surely; we are simply lucky in our circumstances, addicts unlucky.

This insight should help humanize our view of addiction: although they are behaving voluntarily, addicts are fully caused in their choices, not self-made. They don’t deserve punitive treatment, such as withholding harm reduction measures (needle exchanges, narcan) that could save them from HIV or overdose (see here (link is external)). By clearly delineating the biological and situational determinants of the choice to use drugs, Heyman’s theory helps to destigmatize addiction, perhaps even more effectively than the disease model.

Compulsion and control

The disease model holds that addictive behavior is compulsive, out of control and thus involuntary, hence symptomatic of a disease. But Heyman rightly points out that there’s nothing involuntary about seeking or consuming drugs and alcohol – such behavior is voluntary in the standard sense that, as is most of our behavior, it’s responsive to the prospect of positive and negative consequences: we choose a course of action in light of the likely outcomes of the choice. Involuntary behavior, such as an eye blink in response to a puff of air, or your stomach growling in the absence of food, isn’t responsive to any outcomes that might follow. Heyman thinks that to call addictive behavior compulsive or out of control misdescribes the behavioral facts about addiction, because, after all, it’s voluntary behavior (pp. 28, 85, 100-1). But, and this is one of my few disagreements, even if it’s voluntary we can still rightly say that an addict’s drug use is sometimes compulsive and out of control. It’s out of control since, as judged from the perspective of the optimal global equilibrium, the addict is consistently making uncontrolled choices: they are uncontrolled by the consideration of long-term costs and benefits that, were it in control, would make his life better. We can also say his behavior is compulsive in the well-defined sense that, unless the balance of rewards changes, there’s an extremely high probability that he’ll repeat the behavior. The addict is virtually compelled to choose drugs by the operative contingencies, which is why he can’t just choose to quit at the drop of a hat.[3] All this seems consistent with Heyman’s model, and makes it fully consistent with the current DSM description of addiction that he quotes: “There is a pattern of repeated self-administration that usually results in tolerance, withdrawal, and compulsive drug-taking behavior…”(p. 28).

To describe addictive behavior as compulsive and out of control also captures the phenomenology of addiction as reported by addicts themselves. They don’t feel in control of their urges; rather they feel compelled to seek out and use their drug of choice, and generally do so. These descriptions of their subjective state accurately mirror the neural state of affairs in their brains, heavily biased as it is in favor of choosing drugs. In granting these descriptions, we therefore aren’t contradicting any facts of the matter, and we gain the addict’s trust by conceding the reality of her experience. Addiction is a disorder of voluntary choice experienced as compulsion, and correctly characterized as a compulsion, given the contingencies in play.

The way out

But given that even compulsive choices are responsive to changed circumstances, addiction itself is amenable to change, not a sealed fate. Thus Heyman’s model has implications for treatment: “Devise a treatment that makes the drug less rewarding, and drug use will decrease in addicts…If addiction is voluntary drug use, then altering the consequences of drug use will alter its frequency. Programs that have taken this approach have had considerable success” (p. 168-9). For those with well-paying jobs at stake (airline pilots, doctors), the prospect of testing positive in random drug screenings works well to end drug use. For those with much less to lose, abstinence can be rewarded by vouchers for goods and services (“contingency management”), and their drug use displaced by supplying non-drug alternatives. Alcoholics Anonymous works because it provides occasions for non-alcoholic socializing, mentors that model sobriety, realistic hope for change, and the opportunity to form social networks in which drinking plays no role. All these reward the many sorts of behavior that involve not drinking.

The immediately reinforcing effects of alcohol and other drugs can be reduced by pharmacological treatment using buprenorphine (link is external), methadone and disulfiram (link is external). Whether chemical or social, treatment works by changing the balance of rewards for the addict, thereby inducing different choices. What doesn’t work are appeals to willpower,[4] punitive approaches such as imprisonment that deliberately withhold rewarding non-drug alternatives, and the opposition of some former addicts to methadone and buprenorphine because these are merely “crutches,” not legitimate adjuncts to treatment.

Even if Heyman’s theory of local vs. global choice is supplanted by a better empirical model of decision-making, his basic point still holds: addiction centrally involves voluntary behavior. In line with other work in behavioral economics,[5] his theory says voluntary behavior often isn’t optimally rational - it contains the seeds of our own undoing. But if Heyman is correct about choice, we can take heart from the fact that, because the global equilibrium is overall more rewarding, it can take control of our behavior if given the chance. The chances increase with help from friends, spouses, and social norms of self-restraint and productivity. The explicit knowledge we are vulnerable to short-term bias helps too: we can take steps to make longer-term costs and benefits more salient and thus more influential, whether dealing with addiction or, for example, climate change. Knowing that local choice is often globally suboptimal, sometimes to our great disadvantage, we’re more likely to devise techniques that enable us to abstain from our current preferences (drugs, alcohol, meat, carbon-intensive lifestyles) in favor of alternatives (non-drug activities, vegetables and grains, commuting by bike, renewable energy sources) that will help avoid personal and social catastrophe.

The time is ripe for the application of behavioral technologies that capitalize on what we’re learning about voluntary choice so that we make better choices, as judged from the perspective of sustained flourishing, individual and collective. Beyond its well-taken critique of the disease model of addiction, Heyman’s book points us in very much the right direction: toward a science of enlightened self-control.

TWC, July, 2009

Notes