The Diagnostic System, by Jason Schnittker (chapter 1)

1 THE CONTESTED ONTOLOGY OF PSYCHIATRIC DISORDERS

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he best place to start a discussion of psychiatric classification is with the people that psychiatric disorders affect directly. Consider two cases, both involving people at the boundary of formal classification. These cases are drawn from the American Psychiatric Association’s most recent volume of clinical cases, designed to help mental health professionals learn more about the latest edition of the Diagnostic and Statistical Manual.1 All of the cases in the volume are based on real people, though their identities have been disguised and their names changed. The cases are not necessarily typical of a disorder. Indeed, many were selected precisely to illustrate the ambiguities surrounding the manual’s criteria.

They are, however, illustrative, especially for those who must struggle with implementing the criteria. The first is Olaf Hendricks, a fifty-one-year-old father.2 Olaf ’s daughter lives overseas, and she recently had a baby. Olaf would like to visit his grandchild, but he is severely anxious about flying.

His anxiety began three years ago when the plane he was on landed during an ice storm. He has flown since that incident, but on his last complete fl ight he cried during landing and takeoff. Subsequent to that, when Olaf was scheduled to fly to his daughter’s wedding, he ultimately refused to board the plane after arriving at the airport. His fear of flying affects more than his family life. It played a role, for instance, in his refusing to accept a promotion that would have involved significant travel. According to Olaf, his anxiety is limited to flying, though with some questioning his psychiatrist discovered that as a child Olaf feared being attacked by a wild animal.

His earlier fear of animals was similar in its intensity to his current fear of

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flying, though it had dissipated because he now lives in a large city where encounters with wild animals are rare. According to the criteria in the Diagnostic and Statistical Manual, Olaf suffers from a specific situational phobia, in this case of flying. His disorder meets all the diagnostic criteria in the manual. It involves intense situational anxiety, it has caused significant distress, and it has caused significant functional impairment. In addition, Olaf also meets the diagnostic criteria for a specific phobia pertaining to animals, but, probably because he is unlikely to encounter wild animals in his current environment, that anxiety plays little obvious role in his life. The DSM permits this additional diagnosis, in part to allow for “significant impairment” that might be entirely unconscious; for example, Olaf might choose to live in a big city precisely to avoid wild animals. Olaf is not required to acknowledge or state this, however, for the psychiatrist to infer that it might matter.

The second case is Andrew Quinn, whose son recently died.3 His son had suffered from depression and substance abuse and, after a struggle, died of an apparent suicide. Andrew visited his psychiatrist two weeks after his son’s death, reporting that he felt life had lost its meaning. The psychiatrist continued to see him on a weekly basis in order to monitor his progress. His symptoms worsened over the next four weeks, with Andrew growing increasingly preoccupied with his son’s death and ruminating over what he might have done differently. Andrew also reported the other symptoms that compose a depressive episode, including sleeplessness, fatigue, sadness, feelings of worthlessness, and a loss of self-confidence. Although these symptoms are recent and form the reason for Andrew’s visit, there are other diagnostically relevant experiences in his history. Andrew had two prior episodes of depression, both occurring more than thirty years ago. According to the diagnostic criteria in the most recent DSM, Andrew is suffering from a major depressive episode. Although his symptoms are typical of grief and his son’s death happened less than two months prior—well within the timeframe in which we might ordinarily still expect some grieving—the DSM emphasizes how depression that begins in grief can eventually grow “autonomous” of that experience and thus be regarded as indicative of a deeper problem.4 Other features of Andrew’s situation are relevant to discerning whether this is a case of clinical depression and not just bereavement. In

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particular, the risk of depression following grief is presumed to be higher for Andrew given his history of depression.

What do these two cases reveal? At one level they reveal something simple: how matters of formal diagnosis hinge on seemingly slight matters. Andrew’s diagnosis hinges on what we regard as real depression and what we believe is an adequate time to grieve. Making a diagnosis also appears to depend on evidence of a preexisting risk, even if, as in Andrew’s case, that risk appeared many years ago. With almost exactly the same experiences and symptoms, a person without a history of depression might be regarded as simply bereaved, not depressed, especially this soon after a son’s death.

Olaf ’s case raises similar issues. In particular, for Olaf there are two sources of anxiety, even though he is concerned about only one. In this case, too, the past is critical. The DSM allows for a diagnosis based on what Olaf experienced in the past. According to the DSM, a disorder might still be present even when it has no apparent symptoms. In this way, the DSM assumes authority over and above what Olaf himself recognizes or appreciates. These two cases also point to the importance of professional judgment in addition to the words and rules of a text. A reliable diagnosis requires that the psychiatrist use the DSM faithfully. Yet a diagnosis also requires that the psychiatrist exert a considerable amount of judgment. In Andrew’s case, the psychiatrist must decide whether Andrew is really suffering from clinical depression, based on insights that probably stretch beyond the DSM. In particular, the psychiatrist must decide if the particular set of symptoms better describes grief or major depression, even though they are closely related. In Olaf ’s case, the psychiatrist must probe further to learn about Olaf ’s other fears, even if those fears have no obvious relationship with his current anxiety. What, though, compels a psychiatrist to use the DSM faithfully? And when presented with complex patients for whom a diagnosis requires reading between the lines, often based on issues that go well into a patient’s past, will all psychiatrists make the same determination? Regardless of the details provided in the DSM, psychiatrists are still left wrangling with the meaning of its text when presented with actual patients.

This book is concerned with the ambiguities surrounding psychiatric classification, of which these examples illustrate only a few. I hope these two

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cases illustrate something else, too. Much of my discussion will be abstract, in the sense that I will focus on the principles guiding the creation and revision of psychiatric nomenclature. Much of my discussion, too, will pertain to aggregate-level data, including prevalence rates, correlations, and population averages. It is my hope, though, that readers will always keep in mind that these issues, in the end, are not abstract; they are personal. They are not about lists of symptoms; they apply to people who are suffering. And debates regarding the best classification systems ultimately seek to impose some sort of significance (or insignificance) over the day-to-day experiences of individuals. The ambiguity surrounding psychiatric classification is not, however, a simple or self-evident matter. It is rooted in the deep ambiguity surrounding mental illness, one that is hard to clarify with even the most scientifically credible diagnostic criteria.

THE DEEP AMBIGUITY OF MENTAL ILLNESS Many illnesses are foreign to the experience of the average person. Epilepsy is serious for those who suffer from it, but most people will never have a seizure. Minor jolts to the head happen periodically, but a traumatic brain injury is severe and has lasting consequences. The flu is seasonal and pervasive, but there are many other diseases that will never infect the average person. Some symptoms are simply remote to our experience, even if we occasionally experience a hint of what lies just beyond the border.

Many of the core symptoms of mental illness, however, are familiar to virtually everyone. Furthermore, in the case of mental illness, differences between the sick and well can appear only a matter of degree. Most people, for example, might not regard themselves as “depressed” in any significant way, but the feeling of being sad or unmotivated is hardly unusual. In fact, such feelings are routine features of everyday life. They are characterized by a wide variety of idiomatic expressions far removed from any medical connotations, as when we say we are feeling “blue” or “downhearted.” Similarly, most people might not panic in the face of something they fear, but virtually

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everyone can appreciate the unease of, for example, public speaking. At a minimum everyone can easily name those things they fear the most. And chances are your fears—whether of snakes, heights, or enclosed spaces—are shared by many other people. We might not even regard these experiences as symptoms at all and, instead, actively seek them out, as when people enjoy the pensive melancholy of music in a minor key.5 Perhaps there is a limit. Hallucinations might be regarded as the most severe kind of psychological symptom. Hearing voices when no one is around or seeing things that are not present represent especially bizarre experiences. And perhaps we can agree that such symptoms are the boundary, the point at which normal and abnormal part ways. Our commonsense view of the world allows only for externally generated auditory and visual cues.

Yet even here the case is not so clear. Everyone appreciates the idea of a “delusion,” and the word is used frequently. But the term is more complex than is suggested by the ease with which people deploy it. “Delusion” implies beliefs that are incorrect, and assessing when thoughts are faulty is difficult. “You’re crazy” is an epithet, of course, but it is also an evaluation. It is an assessment of another person’s motives, beliefs, or rationality, and the term is often used indiscriminately. Furthermore, hallucinations are not entirely uncommon, suggesting that the frequency with which something occurs provides no guidance regarding its normality. Many people can appreciate the feeling of dislocation, for example, that comes from not getting enough sleep. Indeed, some studies find that more than a third of people experience hallucinations of some kind in their lifetime, even if most of those experiences are not associated with any specific psychiatric disorder.6 The symptoms of mental illness, then, are the “stuff of life.”

Not only does the public have a reasonable sense about what the symptoms of mental illness feel like; it also has some intuitive grasp about what causes them. This, too, makes mental illness different from many other kinds of illness. The average person might have little sense about what causes epilepsy, for example, and so will seek the authority of an expert to diagnose it. Similarly, many people intuit that good and bad health “run in the family” and, thus, recognize the importance of genetic influences.

Even so, people still leave the formal diagnosis of inherited conditions to

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professionals. For some things, like a broken bone, everyone understands the traumas that can cause it, but they still accept that the final determination of whether a bone is broken rests with an X-ray. For mental illness, the situation is quite different. The average person can easily appreciate the role of stress in feeling overwhelmed or maybe even depressed, without any sort of technological intermediary. The issue is not that such causes lack reality for being common. To the contrary, “everyday” causes gain credibility precisely because we appreciate how potent they are. The death of a loved one can produce profound sadness, one seemingly impervious to time and the support of friends. When individuals recognize themselves as suffering from depression they can almost always identify a precipitating cause and have little doubt about its significance. Science, too, has confirmed the reality of environmental causes of this sort, but the public has not waited for the insights of empirical research to draw its own conclusions.

Perhaps because the symptoms of mental illness are so common and explanations so easy to grasp, the concept of mental illness invites controversy.

When everyone knows something about sadness—about what it feels like, about what causes it—claims of authority, even with respect to official diagnosis, can appear unnecessary or dubious. The public is quick to judge whether they think someone is “really” depressed, even as they withhold judgment about most other medical disorders. And when people are presented with so many potential causes of mental illness, the boundaries between what is or is not illness become porous. If sadness—even severe sadness—comes from living an ordinary life, how can depression ever be considered a disease? What sort of treatment could we deem absolutely necessary?

These debates are not merely matters of idle speculation. They have deep consequences. Parents struggle with whether to seek treatment for their misbehaving or underperforming children. Spouses struggle with the addictions of their partners. Policy makers struggle with how to provide health care to those who need it most. And psychiatrists struggle with crafting the most accurate diagnostic criteria. In the end, these concerns are concrete.

The form of the question becomes personal: What causes my suffering? Do I have a problem, and, if so, what can I do about it? Questions of this sort

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are existential as much as medical. Formal diagnostic criteria are a different matter—the DSM provides some answers—but they have no less settled answers, and they, too, are at least partly a matter of philosophy.

CONTROVERSIES SURROUNDING FORMAL DIAGNOSTIC CRITERIA FOR PSYCHIATRIC DISORDERS Formal diagnostic criteria for psychiatric disorders have existed for decades.

They provide the “rules” for making professional diagnoses. They also provide the “catalogue” of relevant psychiatric symptoms. When applied correctly and consistently, formal diagnostic criteria are intended to produce a lingua franca for mental health professionals. They admit some experiences as symptoms but exclude others. They also provide thresholds and decision rules for adjudicating significance. This is what we regard as depression. These symptoms are significant. This is the point at which we say these symptoms reflect clinical depression rather than normal sadness.

Mental illnesses are real, but there is little that is settled about the classification of psychiatric disorders. This is perhaps especially so in the twentyfirst century—a statement that would appear paradoxical given the advanced state of contemporary science but is not in light of the details of this science.

Scientists continue to debate what psychiatric disorders are, what causes them, and even the degree to which they are significant in the lives of those who experience them. The pages of leading scientific journals are fi lled with new breakthroughs, but so, too, are they replete with ongoing controversies about what diagnostic criteria ought to be. Indeed, the controversies seem quickly to follow the breakthroughs. Even basic premises—ones scientists in a certain field might presumably agree upon—are contested. Discussing a study that reported a high prevalence of psychiatric disorders in the general population, for instance, Jerome Wakefield argues that the evidence for this claim, although based on popular and official formal diagnostic criteria, was premised on “invalid” measures that showed little fidelity to “true” disorders

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and wrongly included “normal” variation in distress.7 Whereas most scientists who study cancer can agree on what cancer is and, given proper tests, can diagnose whether a person has it, no such consensus exists among those who study psychiatric disorders. There is perhaps a stubborn insistence on using the DSM, but, if anything, the science of psychiatric disorders has pushed the field further from consensus.

Even among those who can agree on what a valid measure of a psychiatric disorder is, there is controversy. At this point, for example, there is considerable evidence that genes play a role in mental illness. Studies of this sort are featured prominently in the news media, with outlets reporting, for example, the discovery of a gene for depression, a gene for alcoholism, or a gene for autism. These claims are provocative, but behind the bold headlines there remains a lot of debate. New studies routinely overturn previous ones.

Even when researchers can agree generically that there are genes—if not a gene—for a disorder, they rarely agree on every single gene that is relevant or even on the scope of the list. Moreover, mounting evidence suggests that the genes underlying one disorder might underlie many other disorders as well. The genes for depression, for example, might be the same as the genes for anxiety. The further science progresses, the less focused genetic influences seem to be—and to some critics the more ephemeral the nature of psychiatric disorders appears. Like a mirage, a final and settled scientific understanding is continuously receding over the horizon.

Occasionally these debates assume a fervid character. Scientists argue, as they always do, but in some debates they fight. Even parties that would otherwise seem to be united in their efforts have drifted further apart over time. Consider, for instance, the architects of the various versions of the DSM. The form of the DSM has changed little over time, and some might regard the various revisions—especially between immediately consecutive editions—as mere updates. Yet a chairman of the taskforce behind the fourth revision of the DSM recently disparaged the authors of the fi fth.

And he did so in no uncertain terms. The title of his book reveals his standpoint: Saving Normal: An Insider’s Revolt Against Out-of-Control Psychiatric Diagnosis, “DSM-5,” Big Pharma, and the Medicalization of Ordinary Life.8 Not only is there disagreement about the thing that scientists interested in

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mental illness should actually study, there is also, it would appear, debate and doubt about whether that thing is good to study at all.

It is tempting to regard these controversies as transitory. Some might argue that it is better to consider the trajectory of science, which clearly shows progress if not a solution to some longstanding problems. The argument goes something like this: Yes, there is controversy surrounding genetic influences, especially regarding the precision of their effects, but no one really doubts that genes play some role. And soon, because there is a natural evolution to scientific knowledge, we will have better treatments, better classifications, and a much better understanding of what causes suffering.

All the current controversies derive from an unsettled understanding of what psychiatric disorders are. Eventually, though, the nature of mental illness will be revealed.

This is a popular line of thought, and it is easy to appreciate the aspirations behind it. Some aspects of the contemporary science surrounding psychiatric disorders do indeed feel revolutionary. One thing that distinguishes the present era from earlier ones, for instance, is the overwhelming optimism surrounding the explanatory power of neuroscience and the human genome. And, to be sure, research on the anatomical and molecular foundations of psychiatric disorders is promising. In the twenty-first century, scientists have an extraordinary number of new tools available to them and, thus far, have put them to good use. Science can now explore the functioning of the brain with high resolution and, in so doing, has discovered real differences between the brains of those who suffer from psychiatric disorders and those who do not.

But enthusiasts generally have something more in mind than simply good science. According to some, contemporary science has the potential eventually to eliminate the cultural baggage that still clings to the concept of psychiatric disorders. In this vein, they see the study of mental illness moving toward the clinical ideal that is already in place for other illnesses.

Thomas Insel, a former director of the National Institute of Mental Health, sees a revolution underway.9 He argues that this revolution will fundamentally transform diagnostic classification from a guessing game into an objective enterprise. Recognizing the controversies of the past but looking forward

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to the future, he joins with others in urging scientists to “set [their] sights higher” and aim for “precision” medicine.10 It is tempting, too, to regard public beliefs as evolving in much the same fashion as science. In many respects, public beliefs regarding mental illness are more sophisticated than they were in the past. Thirty years ago the representation of people with mental illness in the media was hardly flattering, and the stigma surrounding psychiatric disorders was strong. Many of the public’s beliefs betrayed a level of ignorance that is hard to imagine today. In 1972, Thomas Eagleton withdrew as George McGovern’s vice presidential running mate over concerns regarding his earlier treatment for depression.

Today, having received treatment for a psychiatric disorder is perhaps less concerning. Indeed, if taking psychiatric medications was summarily disqualifying, there would be far fewer capable politicians and professionals. In addition, public-opinion data reveal a more attuned and responsive culture.

Whereas the public was once ill informed, it is now knowledgeable. The public is increasingly adopting the biomedical model of mental illness, for instance, accepting the idea that psychiatric disorders have biological causes.

Furthermore, the idea that people are personally responsible for mental illness has receded. For example, the public is less likely to attribute alcohol abuse to personal character or weakness, accepting it, at least in part, as a disease. In short, the argument goes, science and culture can and will evolve together, together fomenting a medical approach. Whatever misconceptions the public had in the past, they are merely reflections of an imperfect understanding, which can be remedied with education.

THE FRAMEWORK OF THE DIAGNOSTIC SYSTEM In this book, I ask us to take a step back. Let me be clear about what I mean.

I will not ask us to ignore fifty years of progress. In fact, this book will discuss the contemporary science of psychiatric disorders in some detail and with approval. Nor will this book ask us to entertain the possibility that a much earlier era was, in some sense, a more tolerant one. Michel Foucault

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