SCIENCE MARCH 15, 2010
by Gene M. Heyman
Harvard University Press, 200 pp., $26.95
In 1970, high-grade heroin and opium flooded Southeast Asia. Military physicians in Vietnam estimated that between 10 percent and 25 percent of enlisted Army men were addicted to narcotics. Deaths from overdosing soared. In May 1971, the crisis exploded on the front page of The New York Times: “G.I. Heroin Addiction Epidemic in Vietnam.” Spurred by fears that newly discharged veterans would ignite an outbreak of heroin use in American cities, President Richard Nixon commanded the military to begin drug testing. In June, the White House announced that no soldier would be allowed to board the plane home unless he passed a urine test. Those who failed could go to an Army-sponsored detoxification program before they were re-tested.
The plan worked. Most GIs stopped using narcotics as word of the new directive spread and the vast minority who were detained produced clean samples when given a second chance. More startlingly, only 12 percent of soldiers who were dependent on opiate narcotics in Vietnam became re-addicted to heroin at some point in the three years after their return to the states. “This surprising rate of recovery even when re-exposed to narcotic drugs,” said the epidemiologist who collected the data, “ran counter to the conventional wisdom that heroin is a drug which causes addicts to suffer intolerable craving that rapidly leads to re-addiction if re-exposed to the drug.”
The story of returning Vietnam veterans overturned the conventional wisdom of “once an addict, always an addict.” The data were hailed as “revolutionary” and “path-breaking." Alas, the lesson became a casualty of generational amnesia. “Once an addict, always an addict” has merely been replaced by a newer and more sleekly scientific version of the same concept, namely, “addiction is a chronic and relapsing brain disease.”
Now comes an important and provocative book called Addiction: A Disorder of Choice by the psychologist Gene Heyman, a research psychologist at McLean Hospital and a lecturer at Harvard. Heyman mounts a devastating assault on the brain-based model of addiction. Not that he views addiction as independent of the brain—no serious person could even entertain such a claim. What he rejects, however, is the notion that excessive drug or alcohol consumption is an irresistible act wholly beyond the user’s control, as the term “addiction,” commonly understood, implies. If anything, Heyman writes, “[a]ddiction … helps us understand voluntary behavior.” How so? “[B]ecause,” he explains, “it is not possible to understand addiction without understanding how we make choices.”
This methodical, clear, and concise book shows why. Addiction: A Disorder of Choice is an invaluable tutorial in how to think about drug addiction. In bucking the medicalization trend, Heyman pits himself squarely against the National Institute on Drug Abuse (NIDA), the nation’s main research facility on addiction, which coined the slogan that “addiction is a chronic and relapsing brain disease.” Since then, the institute’s brain disease model has been widely adopted. It is promoted at major rehab institutions such as the Betty Ford Center and Hazelden and is now a staple of anti-drug education in high schools and of counselor education. "The emerging paradigm views addiction as a chronic, relapsing brain disorder," said a Newsweek cover story on addiction.
What makes addiction a brain disease? The answer, neuroscientists give, is that it is tied to changes in brain structure and function. True enough—repeated use of drugs such as heroin, cocaine, alcohol, and nicotine do change the brain. They trigger intracellular biochemical events that eventually modify brain circuits that mediate the experience and memory of pleasure. Scientists have traced these nerve pathways as they emerge from the underside of the brain and sweep out to regions, such as the nucleus accumbens, hippocampus, and prefrontal cortex, which are associated with reward, motivation, memory, judgment, inhibition, and planning.
In a most impressive display of brain technology, scientists have used scanning technology to observe metabolic activity of the brain in action. In a typical demonstration, addicts are shown drug-related videos that depict people handling a crack pipe or needle. Brain scans capture the viewer’s reaction to these provocative images and represent it as glowing technicolor splotches of color that represent activation in drug-sensitized brain regions. (Videos of neutral content, such as landscapes, induce no such response.) Even in users who quit several months ago, neuronal alterations may persist, leaving them vulnerable to sudden, strong urges to use. But addiction is not a brain state, it is a behavior. As philosopher Daniel Shapiro of West Virginia University puts it, “You can examine pictures of brains all day, but you’d never call anyone an addict unless he acted like one.”
Furthermore, as Heyman says, much of the public, and a dismaying number of psychiatrists, psychologists, and neuroscientists, mistakenly believe that if a behavior is influenced by genes or mediated by the brain then the actor cannot choose his actions. While every behavior has a biological correlate (and a genetic contribution) and every experience that changes behavior does so by changing the brain, the critical question, Heyman wisely says, is not whether brain changes occur (they do) but whether these changes block the influence of the factors that support self-control.
In fairness, the scientists who forged the brain disease concept had good intentions. By placing addiction on equal footing with more conventional medical disorders, they sought to create an image of the addict as a hapless victim of his own wayward neurochemistry. They hoped this would inspire companies and politicians to allocate more funding for treatment. Also, by emphasizing dramatic scientific advances, such as brain imaging techniques, and applying them to addiction, they hoped researchers might reap more financial support for their work. Finally, promoting the idea of addiction as a brain disease would rehabilitate the addict’s public image from that of a criminal who deserves punishment into a sympathetic figure who deserves treatment.
Good intentions aside, is the “brain disease” of addiction really beyond the control of the addict in the same that way that the symptoms of Alzheimer’s disease or multiple sclerosis are beyond the control of the afflicted? Showing how the two differ is an important theme of the book. If, as Heyman says, “drug-induced brain change is not sufficient evidence that addiction is an involuntary disease state,” then how are we to distinguish between voluntary and involuntary behavior?
Heyman’s answer is that "voluntary activities vary systematically as a function of their consequences, where the consequences include benefits, costs, and values.” Take, for example, the case of addicted physicians and pilots. When they are reported to their oversight boards they are monitored closely for several long years; if they don’t fly right, they have a lot to lose (jobs, income, status). It is no coincidence that their recovery rates are high. Via entities called drug courts, the criminal justice system applies swift and certain sanctions to drug offenders who fail drug tests—the threat of jail time if tests are repeatedly failed is the stick—while the carrot is that charges are expunged if the program is completed. Participants in drug courts tend to fare significantly better than their counterparts who have been adjudicated as usual. In so-called contingency management experiments, subjects addicted to cocaine or heroin are rewarded with vouchers redeemable for cash, household goods, or clothes. Those randomized to the voucher arm routinely enjoy better results than those receiving treatment as usual.
Contingencies are the key to voluntariness. No amount of reinforcement or punishment can alter the course of an entirely autonomous biological condition. Imagine bribing an Alzheimer’s patient to keep her dementia from worsening, or threatening to impose a penalty on her if it did. This is where choice comes in: choosing an alternative to drug use. Heyman realizes how odd this might seem. How can otherwise rational people choose self-destruction unless they are diseased? This question was raised in colonial America. Dr. Benjamin Rush, also known as the father of American psychiatry, was among the first to promote the notion that alcoholism was a disease. And he did so not on the basis of medical evidence, Heyman reminds us, “but rather [upon] the assumption that voluntary behavior is not self-destructive.”
It may strike some as insensitive to insist that addiction is a disorder of choice. “I have never come across a single drug-addicted person who told me [he or she] wanted to be addicted," Nora Volkow, the current director of NIDA says. Exactly so. How many of us have ever come across a person who wanted to be fat? So many undesirable outcomes in life are achieved incrementally. In a choice model, full-blown addiction is the triumph of feel-good local decisions (“I’ll use today”) over punishing global anxieties (“I don’t want to be an addict tomorrow”). Let’s follow a typical trajectory. At the start of an episode of addiction, the drug increases in hedonic value while once-rewarding activities such as relationships, job, or family recede in value. Although the appeal of using starts to fade as consequences pile up—spending too much money, disappointing loved ones, attracting suspicion at work—the drug still retains value because it salves psychic pain, suppresses withdrawal symptoms, and douses intense craving.
At some point, however, even these benefits come to be outweighed by adverse fallout. The balance shifts and the addict tips into recovery. The idea is to accelerate the process by, as Heyman says, “chang[ing] … conditions that markedly reduce the value of the drug relative to the nondrug alternative.” This can be achieved through treatment, imposing credible threats—recall the case of impaired pilots and physicians—or the development of new modes of gratification that compete with drugs.
The author of Addiction: A Disorder of Choice is a behavioral psychologist, not a clinician. This may be why he does not pay much attention to the reasons people use drugs. Clinicians, like myself, tend to see addiction as a form of self-medication. Addicts are drawn to drugs to salve depression, anxiety, boredom, self-loathing. Heyman’s training as a behavioral psychologist may also explain why he writes of addiction to drugs as barely distinct from other kinds of excessive appetites (for food, sex, shopping) in the context of the choice model. Here he does not fully persuade.
In all, Addiction should be required reading for anyone who treats patients, researches addiction, or devises policy surrounding drug-related crime. All should benefit deeply from Heyman’s key idea: "that the idea [of] addiction [as] a disease has been based on a limited view of voluntary behavior." Moreover, the fact that the biological basis does not prevent drug use from coming under the influence of costs and benefits has implications for society. “[A]ccording to Western legal traditions,” he writes, “individuals are usually held responsible for those activities that are susceptible to the influence of their consequences and, conversely, individuals are not responsible for those activities that vary little or not at all as a function of consequences." Willie Sutton, Heyman reminds us, had alternatives to bank robbery; Patty Hearst not so much. The law did not treat them the same way. Accordingly, society should make distinctions between those suffering conventional brain diseases like Alzheimer’s and multiple sclerosis and the disorder of addiction.
Finally, Heyman uses the phenomenon of addiction to make a profound point about neuroscientific progress in general. "The implication is that as we learn more about a disorder,” he writes, “the more likely it is to be thought of as a disease"—and, consequently, as a condition whose course cannot be modified by its foreseeable consequences. Indeed, reconciling advances in brain science with their meaning for personal, legal, and civic notions of agency and responsibility will be one of our next major cultural projects.
Progress in brain science will also force a confrontation with the fact that the common interpretation of pathological behavior is often informed by a primitive form of dualism. If biological roots can be found, then we reflexively think “disease”—as in the obliteration of choice-making ability. The mechanical “brain disease” rhetoric is a symptom of the growing tendency to privilege neuroscientific explanations as the most authentic way of understanding human behavior.
Sally Satel is a psychiatrist and resident scholar at the American Enterprise Institute.