Editor's Note: Read our blog series on psychiatry's new rulebook, the DSM-5.

In February 1969 David L. Rosenhan showed up in the admissions office of a psychiatric hospital in Pennsylvania. He complained of unfamiliar voices inside his head that repeated the words “empty,” “thud” and “hollow.” Otherwise, Rosenhan had nothing unusual to report. He was immediately admitted to the hospital with a diagnosis of schizophrenia.

Between 1969 and 1972 seven friends and students of Rosenhan, a psychology professor then at Swarthmore College, ended up in 11 other U.S. hospitals after claiming that they, too, heard voices—their sole complaint. Psychiatrists slapped them all with a diagnosis of schizophrenia or bipolar disorder and stuck them in psychiatric wards for between eight and 52 days. Doctors forced them to accept antipsychotic medication—2,100 pills in all, the vast majority of which they pocketed or tucked into their cheeks. Although the voices vanished once Rosenhan and the others entered the hospitals, no one realized that these individuals were healthy—and had been from the start. The voices had been a ruse.

The eight pseudopatients became the subject of a landmark 1973 paper in Science, “On Being Sane in Insane Places.” The conclusion: psychiatrists did not have a valid way to diagnose mental illness.

Rosenhan’s experiment motivated a radical transformation of the essential reference guide for psychiatrists: the Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association (APA). The revamped DSM, dubbed DSM-III and published in 1980, paired every ailment with a checklist of symptoms, several of which were required for a diagnosis to meet the book’s standards. Earlier versions of the DSM contained descriptive paragraphs that psychiatrists could interpret more loosely. This fundamental revision survives today.

The APA is now working on the fifth version of the hefty tome, slated for publication in May 2013. Because the DSM-IV was largely similar to its predecessor, the DSM-5 embodies the first substantial change to psychiatric diagnosis in more than 30 years. It introduces guidelines for rating the severity of symptoms that are expected to make diagnoses more precise and to provide a new way to track improvement. The DSM framers are also scrapping certain disorders entirely, such as Asperger’s syndrome, and adding brand-new ones, including binge eating and addiction to gambling.

In the past the APA has received harsh criticism for not making its revision process transparent. In 2010 the association debuted a draft of the new manual on its Web site for public comment. “That’s never been done before,” says psychiatrist Darrel Regier, vice chair of the DSM-5 Task Force and formerly at the National Institute of Mental Health. The volume of the response surprised even the framers: 50 million hits from about 500,000 individuals and more than 10,000 comments so far.

Critics swarmed the drafts. Some psychiatrists contend that the volume still contains more disorders than actually exist, encouraging superfluous diagnoses—particularly in children. Others worry that the stricter, more precise diagnostic criteria may inadvertently give insurance companies new ways to deny medication to patients who need it.

The debates surrounding the manual’s revisions are not merely back-office chatter. Although many psychiatrists do not sit down with the DSM and take its scripture literally—relying instead on personal expertise to make a diagnosis—the DSM largely determines the type of diagnoses clinicians make. Insurance companies often demand an official DSM diagnosis before they pay for medication and therapy. Many state educational and social services—such as after-school programs for kids with autism—also require a DSM diagnosis. Consequently, psychiatrists cannot dole out diagnoses of their own invention. They are bound to the disorders defined by the DSM.

Therefore, psychiatrists cannot ignore the new manual and go about business as usual. They must adapt, especially if they want to be sure that their patients keep receiving affordable treatment. Yet this diagnostic bible is a work in progress. In fact, although the revisions are 90 percent complete, the APA may still make significant changes and even delay the book’s official release. Even after its publication, the DSM will remain a snapshot of a field in flux—an ambitious attempt to capture an evolving, often ambiguous science.

Diagnosing the DSM

Psychiatrists have been kicking around the DSM-5 in a scientific scrimmage that dates back to 1999, when the APA and the NIMH sponsored a meeting to jump-start planning. More than 13 joint conferences later, committees of psychiatrists and psychologists have churned out dozens of white papers outlining how best to overhaul psychiatry’s bible. In April 2006 the APA appointed clinical psychologist David Kupfer and Regier as chair and vice chair, respectively, of a team of 27 scientists assigned to digest the research literature and propose revisions to this historic volume.

Right away researchers fingered several major failings of the DSM-IV. First, many of the symptom checklists were so similar that many patients left a psychiatrist’s office with several official diagnoses rather than just one. It is unlikely that large numbers of patients each have a variety of different disorders, says Steven Hyman, a task force member. Rather, he suggests, a single cognitive or biological process—maladaptive thought patterns, for instance, or atypical brain development—may manifest itself in symptoms of more than one ailment. To address this problem, curators of the new book eliminated over a dozen less distinct disorders, in some cases merging them into larger categories of illness, such as the autism spectrum [see “Psychosis Revisited”].

Patients and their psychiatrists often struggle with the opposite problem, too: a person’s symptoms might be fewer or milder than those listed in the DSM or simply do not match any disorder in the manual. As a result, psychiatrists slap large factions of their clientele with a “disorder not otherwise specified” label. The most frequently diagnosed eating disorder is “eating disorders not otherwise specified.” The predominant autism spectrum disorder? By most estimates it is “pervasive developmental disorder not otherwise specified.” The third most common personality disorder is, you guessed it, “personality disorder not otherwise specified.” Health professionals rely so heavily on catchall diagnoses because the current DSM has some serious gaps in its diagnostic offerings and has some superfluous entries.

In addition to eliminating ailments, the DSM-5 will encourage psychiatrists to collect more detailed information about patients’ symptoms. With more data to consider and more complete descriptions in the manual, the theory goes, psychiatrists are more likely to find a proper match between a patient and an illness.

Degrees of Dysfunction

To improve diagnoses, the DSM-5 asks doctors to grade the severity of their clients’ symptoms. A verdict of major depression, for example, will include a rating for each symptom—insomnia, say, or thoughts of suicide. Similarly, a child who is diagnosed with attention-deficit hyperactivity disorder would also receive an assessment of her ability to focus, ranging from poor to excellent.

This ideological shift signals a step away from the simplistic notion that mental illnesses are discrete conditions wholly distinct from a healthy state of mind. Instead the new volume reflects the idea that everyone falls on a spectrum that stretches from typical behavior to various shades of dysfunction. Where you land on that scale determines whether your symptoms merit treatment. This approach might assist, for example, psychiatrists evaluating a patient’s attention problems, which can seem almost ubiquitous in younger children. Considering an individual in the context of others can make it easier to flag the neediest cases. Psychiatrists, of course, already use many scales and questionnaires in their practice. The DSM-5 will standardize such ratings so that doctors use the same scales to measure a given disorder and increase the chances they will reach similar conclusions about comparable patients.

These detailed assessments should allow treatments to become more tailored. For example, a patient with mild signs of depression is more likely to benefit from therapy and lifestyle changes than from antidepressant medication, which recent findings suggest is more

effective for severe depression. Psychiatrists and patients will also gain a new way to track improvement. A shift in the depression gauge from “severe” to “moderate” may in itself lift a patient’s spirits, motivating him to stick to the regimen propelling his progress.

Although most psychiatrists support the idea of measuring severity, practitioners have also voiced various concerns. Placing several previously distinct disorders under the umbrella of autism, for example, has ignited fears that autistic people with less severe symptoms will no longer qualify for a diagnosis or treatment. Questions have also been raised about how insurance companies will respond: Could these scales create barriers to treatment? A simple diagnosis of depression may no longer be enough to qualify a patient for antidepressants—insurance companies may demand that a patient’s depression meet a certain severity level.

The new procedures will require patients to complete more evaluations and surveys than ever before, culminating in larger amounts of paperwork and more time spent on every diagnosis. Some psychiatrists worry the extra effort will deter their peers from using the DSM properly—and a few have even proposed doing away with the severity ratings altogether. More broadly, psychiatrists have also objected to the addition of certain disorders that they consider dubious.

A Primitive Guide?

A second sweeping change to the DSM is the way it clusters disorders. The DSM-IV was organized around three categories of illness. One group captured all major clinical disorders, such as depression, bipolar disorder and schizophrenia. Another section encompassed all personality and developmental disorders. The third category contained “medical” problems that might play a role in mental illness: diabetes or hypothyroidism, for instance, can exacerbate depression. The DSM-5 throws these relatively arbitrary divisions out the window. Instead it arranges diseases chronologically, starting with illnesses that psychiatrists typically diagnose in infancy or childhood—such as neurodevelopmental disorders—and moving toward those frequently found in adults, such as sexual dysfunctions. When evaluating a toddler, for instance, a psychiatrist can focus on the front of the DSM-5 or the beginning of a chapter, say, on depressive disorders, where he or she will find the types of depression most likely to afflict children.

As genetic and neuroimaging studies improve our understanding of the relations among ailments, the DSM will be able to swiftly adapt. The APA plans to publish the new manual in print and as a “living” electronic document that can be updated frequently as version 5.1, 5.2, and so on. (The APA dispensed with Roman numerals to make this labeling practical.)

Eventually researchers aim to root the DSM in the biology of the brain. Someday scientists hope to find useful “biomarkers” of mental illness—genes, proteins or patterns of electrical activity in the brain that can serve as unique signatures of psychiatric problems. Lab tests based on such markers would make diagnosing mental illness easier, faster and more precise.

“The DSM has always been a primitive field guide to the world of psychological stress because we know very little about the underlying neural chemistry of psychological symptoms,” says psychiatrist Daniel Carlat of the Tufts University School of Medicine. “But over the past 60 or 70 years the categories have become more reliable and meaningful.” No one argues that the DSM flawlessly mirrors mental illness as people experience it, but every revision sharpens the reflection—and with it, people’s understanding of themselves.

MORE ON THE DSM-5

Fast Facts: A New Guide to Your Psyche

1.The fifth version of psychiatry’s bible, the Diagnostic and Statistical Manual of Mental Disorders, slated for publication in May 2013, represents the first substantial change to psychiatric diagnosis in more than 30 years.

2.In 2010 the American Psychiatric Association debuted a draft of the new manual on their Web site that has so far received 50 million hits from about 500,000 individuals, many of them critics.

3.The revised manual will very likely scrap psychiatry staples such as Asperger’s syndrome and paranoid personality disorder.

4.Additions to the diagnostic menu are likely to include an ailment for children marked by severe temper tantrums and for adults a type of sex addiction.

Psychosis Revisited

Schizophrenia is characterized by a tenuous grasp of reality, difficulty thinking and speaking clearly, and unusual emotional responses. In today’s diagnostic manual, the DSM-IV, this complex disorder is split up into the following “types”:

Paranoid: delusions and auditory hallucinations but normal speech and emotional responses.

Disorganized: erratic speech and behavior and muted emotions.

Catatonic: unusual postures and movements or paralysis.

Residual: very few typical symptoms but some odd beliefs or unusual sensory experiences.

Undifferentiated: none of the other types.

Yet another form of the illness is shared psychotic disorder: when someone develops the same delusions as a friend or family member with schizophrenia.

Soon you can forget all these variants. As with certain personality disorders, there is little evidence for the existence of these discrete categories. Catatonia, for instance—an intermittent “freezing” of the limbs—also accompanies bipolar disorder, post-traumatic stress disorder and depression. Therefore, psychiatrists say it makes little sense to call it a form of schizophrenia. Catatonia also does not respond well to the antipsychotic medications used to treat schizophrenia.

Even as it sheds these subtypes, the DSM-5 embraces novel forms of psychosis. The most contentious is attenuated psychosis syndrome, a cluster of warning signs that some researchers think precede the frequent delusions and hallucinations that characterize the full-blown disorder. Its purpose is to catch young people at risk and prevent this insidious progression. Critics contend, however, that two thirds of the children who qualify for the at-risk criteria never develop real psychosis and may unnecessarily receive powerful drugs [see “At Risk for Psychosis?” by Carrie Arnold; Scientific American Mind, September/October 2011]. After all, about 11 percent of us sometimes hear voices or engage in moments of intense magical thinking with little or no distress.

Another controversial addition is disruptive mood dysregulation disorder, a diagnosis for kids that carries less stigma than its predecessor, childhood bipolar disorder. Since about 2000, diagnoses of pediatric bipolar disorder have jumped at least fourfold in the U.S. Many psychiatrists, however, argued that their peers were mislabeling a condition that was not bipolar disorder at all and treating children with strong drugs before knowing what really ailed them.

Very few people younger than 20 develop true bipolar disorder, in which moods swing between depression and mania. The vast majority of the kids who received the label did not, in fact, oscillate in this way. Instead they were in a bad mood all the time and frequently exploded in anger and physical violence, even in response to a minor offense. Because of these differences, disruptive mood dysregulation disorder describes a child (younger than 10) who is constantly irritable and has extreme temper tantrums about three times a week.

The APA says this pediatric entry will “provide a ‘home’ for these severely impaired youth,” but some critics worry doctors will dole out the diagnosis like lollipops to droves of tantrum-prone toddlers. The treatment is the same, despite the new name: a mixture of mood stabilizers, antipsychotics, antidepressants and stimulants. —F.J.

Personality Problems

To a psychologist, a personality consists of persistent patterns of thought, emotion and behavior. Someone with a personality disorder has rigid and dysfunctional patterns that disrupt his or her ability to maintain healthy relationships. The current encyclopedia of mental illness, the DSM-IV, describes 10 such conditions. These include paranoid personality disorder—the inability to trust others and an irrational belief that people are out to get you—and narcissistic personality disorder, an exaggerated sense of self-importance, a need for constant admiration and excessive envy of others.

Suspiciously, between 40 and 60 percent of all psychiatric patients are diagnosed with a personality disorder, hinting that symptoms of at least some of these “disorders” resemble typical behavior too closely. In addition, psychiatrists often diagnose the same patient with more than one ailment, suggesting significant overlap. For example, people with both histrionic and narcissistic personality disorders insist on being the center of attention, take advantage of their families and friends, and have trouble reading others’ emotions.

The upshot: DSM-5’s editors nixed histrionic personality disorder. Paranoid, schizoid and dependent personality disorders are also gone. Your personality can still, however, be narcissistic, antisocial, avoidant, borderline, obsessive-compulsive or “schizotypal.” —F.J.

Good-bye to Asperger’s?

Certain behavioral quirks have long been thought to distinguish Asperger’s syndrome from other autistic disorders. “Aspies,” as people with this affliction sometimes call themselves, tend to develop intense fascination with very specific objects or facts—the wheels of toy cars or the names of constellations—in the absence of a general interest in, say, automotive mechanics or astronomy. Now the diagnosis will disappear, and Aspies may find an important part of their identity stripped away.

Currently Asperger’s is one of five so-called pervasive developmental disorders, along with autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), and the lesser-known Rett syndrome and childhood disintegrative disorder (CDD). All these problems are characterized by deficits in communication and social skills as well as by repetitive behaviors. Indeed, the APA has decided that four of the five disorders—autistic disorder, Asperger’s, CDD and PDD-NOS—are so similar that they should all be placed into a new category called autism spectrum disorder (ASD). Psychiatrists using the new DSM will give anyone on the spectrum a diagnosis of ASD, along with a rating of illness severity.

Children whom psychiatrists would previously have diagnosed with CDD fall at the more severe end of the spectrum. They typically experience an almost complete deterioration of social and communication skills starting sometime between the ages of two and 10. Asperger’s patients will land on the milder end. They generally do not show language delays and, in fact, often display excellent verbal skills. Rett syndrome, in which known genetic mutations stunt physical growth, along with language and social skills, is gone from the manual entirely. Ironically, the APA is eliminating it because a genetic test for the condition makes diagnosis so precise and straightforward. For now the DSM prefers to limit itself to a blunter diagnostic measure: behavior.

Statistical studies published in 2011 and 2012 confirm that the DSM-5 criteria for autism are more accurate than those penned in the DSM-IV. The revised guidelines practically guarantee that anyone told they have the disorder really has it. To qualify as autistic by the new manual, a patient must meet five of seven symptoms—a higher bar than the six-of-12-symptom cutoff in the DSM-IV.

Some psychiatrists say the new rules are too strict: they worry some high-functioning autistic people, such those now diagnosed with Asperger’s, may not meet the criteria and may miss out on educational and medical services as a result. On the other hand, if people with milder autismlike symptoms do make it onto the spectrum, the lack of an Asperger’s label could benefit them. States such as California and Texas now provide educational and social services to people with autism that they deny to those with Asperger’s. Some parents argue, though, that limited resources should go to kids with more severe symptoms before anyone else. —F.J.

Craving Cash, Food and Sex

Several new types of addiction may appear in the upcoming version of psychiatry’s bible, the DSM-5. Gambling disorder is one. In the past decade studies have shown that people get hooked on gambling the same way they become addicted to drugs and alcohol and that they benefit from the same kind of treatment—group therapy and gradual withdrawal. Neuroimaging research has revealed that the brains of drug addicts and those of problematic gamblers respond to reminders of drugs and monetary rewards in similar ways: their reward circuits light up, much more than casual gamblers or one-time drug users. The DSM-5 may also include obsessions with food and sex:

Binge Eating Disorder

Consuming “an amount of food that is definitely larger than most people would eat in a similar period of time under similar circumstances” and lacking control over what, how much or how fast one eats.

Hypersexual Disorder

Having unusually intense sexual urges for at least six months or spending excessive amounts of time having sex in response to stress or boredom, without regard for physical or emotional harm to oneself or others, despite the fact that it interferes with social life and work.

Absexual Disorder

Feeling aroused by moving away from sexuality or behaving as though moralistically opposed to sex. As sex educator Betty Dodson told Canadian newspaper Xtra! West, these are “folks who get off complaining about sex and trying to censor porn.” —F.J.

This article was published in print as "Redefining Mental Illness."