National Institute of Mental Health (NIMH): DSM is flawed and outdated.

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Transforming Diagnosis

By Thomas Insel on April 29, 2013

In a few weeks, the American Psychiatric Association will release its new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). This volume will tweak several current diagnostic categories, from autism spectrum disorders to mood disorders. While many of these changes have been contentious, the final product involves mostly modest alterations of the previous edition, based on new insights emerging from research since 1990 when DSM-IV was published. Sometimes this research recommended new categories (e.g., mood dysregulation disorder) or that previous categories could be dropped (e.g., Asperger’s syndrome).1

The goal of this new manual, as with all previous editions, is to provide a common language for describing psychopathology. While DSM has been described as a “Bible” for the field, it is, at best, a dictionary, creating a set of labels and defining each. The strength of each of the editions of DSM has been “reliability” – each edition has ensured that clinicians use the same terms in the same ways. The weakness is its lack of validity. Unlike our definitions of ischemic heart disease, lymphoma, or AIDS, the DSM diagnoses are based on a consensus about clusters of clinical symptoms, not any objective laboratory measure. In the rest of medicine, this would be equivalent to creating diagnostic systems based on the nature of chest pain or the quality of fever. Indeed, symptom-based diagnosis, once common in other areas of medicine, has been largely replaced in the past half century as we have understood that symptoms alone rarely indicate the best choice of treatment.

Patients with mental disorders deserve better. NIMH has launched the Research Domain Criteria (RDoC) project to transform diagnosis by incorporating genetics, imaging, cognitive science, and other levels of information to lay the foundation for a new classification system. Through a series of workshops over the past 18 months, we have tried to define several major categories for a new nosology (see below). This approach began with several assumptions:

  • A diagnostic approach based on the biology as well as the symptoms must not be constrained by the current DSM categories,
  • Mental disorders are biological disorders involving brain circuits that implicate specific domains of cognition, emotion, or behavior,
  • Each level of analysis needs to be understood across a dimension of function,
  • Mapping the cognitive, circuit, and genetic aspects of mental disorders will yield new and better targets for treatment.

It became immediately clear that we cannot design a system based on biomarkers or cognitive performance because we lack the data. In this sense, RDoC is a framework for collecting the data needed for a new nosology. But it is critical to realize that we cannot succeed if we use DSM categories as the “gold standard.”2 The diagnostic system has to be based on the emerging research data, not on the current symptom-based categories. Imagine deciding that EKGs were not useful because many patients with chest pain did not have EKG changes. That is what we have been doing for decades when we reject a biomarker because it does not detect a DSM category. We need to begin collecting the genetic, imaging, physiologic, and cognitive data to see how all the data – not just the symptoms – cluster and how these clusters relate to treatment response.

That is why NIMH will be re-orienting its research away from DSM categories. Going forward, we will be supporting research projects that look across current categories – or sub-divide current categories – to begin to develop a better system. What does this mean for applicants? Clinical trials might study all patients in a mood clinic rather than those meeting strict major depressive disorder criteria. Studies of biomarkers for “depression” might begin by looking across many disorders with anhedonia or emotional appraisal bias or psychomotor retardation to understand the circuitry underlying these symptoms. What does this mean for patients? We are committed to new and better treatments, but we feel this will only happen by developing a more precise diagnostic system. The best reason to develop RDoC is to seek better outcomes.

RDoC, for now, is a research framework, not a clinical tool. This is a decade-long project that is just beginning. Many NIMH researchers, already stressed by budget cuts and tough competition for research funding, will not welcome this change. Some will see RDoC as an academic exercise divorced from clinical practice. But patients and families should welcome this change as a first step towards "precision medicine,” the movement that has transformed cancer diagnosis and treatment. RDoC is nothing less than a plan to transform clinical practice by bringing a new generation of research to inform how we diagnose and treat mental disorders. As two eminent psychiatric geneticists recently concluded, “At the end of the 19th century, it was logical to use a simple diagnostic approach that offered reasonable prognostic validity. At the beginning of the 21st century, we must set our sights higher.”3

The major RDoC research domains:

Negative Valence Systems
Positive Valence Systems
Cognitive Systems
Systems for Social Processes
Arousal/Modulatory Systems

References

 1Mental health: On the spectrum. Adam D. Nature. 2013 Apr 25;496(7446):416-8. doi: 10.1038/496416a. No abstract available. PMID: 23619674

 2Why has it taken so long for biological psychiatry to develop clinical tests and what to do about it? Kapur S, Phillips AG, Insel TR. Mol Psychiatry. 2012 Dec;17(12):1174-9. doi: 10.1038/mp.2012.105. Epub 2012 Aug 7.PMID:22869033

 3The Kraepelinian dichotomy - going, going... but still not gone. Craddock N, Owen MJ. Br J Psychiatry. 2010 Feb;196(2):92-5. doi: 10.1192/bjp.bp.109.073429. PMID: 20118450


 

Psychiatry divided as mental health 'bible' denounced

Guest editorial: "One manual shouldn't dictate US mental health research" by Allen Frances

The world's biggest mental health research institute is abandoning the new version of psychiatry's "bible" – the Diagnostic and Statistical Manual of Mental Disorders, questioning its validity and stating that "patients with mental disorders deserve better". This bombshell comes just weeks before the publication of the fifth revision of the manual, called DSM-5.

On 29 April, Thomas Insel, director of the US National Institute of Mental Health (NIMH), advocated a major shift away from categorising diseases such as bipolar disorder and schizophrenia according to a person's symptoms. Instead, Insel wants mental disorders to be diagnosed more objectively using genetics, brain scans that show abnormal patterns of activity and cognitive testing.

This would mean abandoning the manual published by the American Psychiatric Association that has been the mainstay of psychiatric research for 60 years.

The DSM has been embroiled in controversy for a number of years. Critics have said that it has outlasted its usefulness, has turned complaints that are not truly illnesses into medical conditions, and has been unduly influenced by pharmaceutical companies looking for new markets for their drugs.

There have also been complaints that widened definitions of several disorder have led to over-diagnosis of conditions such as bipolar disorder and attention deficit hyperactivity disorder.

Now, Insel has said in a blog post published by the NIMH that he wants a complete shift to diagnoses based on science not symptoms.

"Unlike our definitions of ischaemic heart disease, lymphoma or AIDS, the DSM diagnoses are based on a consensus about clusters of clinical symptoms, not any objective laboratory measure," Insel says. "In the rest of medicine, this would be equivalent to creating diagnostic systems based on the nature of chest pain, or the quality of fever."

Insel says that elsewhere in medicine this type of symptom-based diagnosis been abandoned over the past half-century as scientists have learned that symptoms alone seldom indicate the best choice of treatment.

To accelerate the shift to biologically based diagnosis, Insel favours an approach embodied by a programme launched 18 months ago at the NIMH called the Research Domain Criteria project.

The approach is based on the idea that mental disorders are biological problems involving brain circuits that dictate specific patterns of cognition, emotion and behaviour. Concentrating on treating these problems, rather than symptoms is hoped to provide a better outlook for patients.

"We cannot succeed if we use DSM categories as the gold standard," says Insel. "That is why NIMH will be reorienting its research away from DSM categories," says Insel.

Prominent psychiatrists contacted by New Scientist broadly support Insel's bold initiative. However, they say that given the time it will take to realise Insel's vision, diagnosis and treatment will continue to be based on symptoms.

Insel is aware that what he is suggesting will take time – probably at least a decade, but sees it as the first step towards delivering the "precision medicine" that he says has transformed cancer diagnosis and treatment.

"It's potentially game-changing, but needs to be based on underlying science that is reliable," says Simon Wessely of the Institute of Psychiatry at King's College London. "It's for the future, rather than for now, but anything that improves understanding of the etiology and genetics of disease is going to be better [than symptom-based diagnosis]."

Michael Owen of the University of Cardiff, who was on the psychosis working group for DSM-5, agrees. "Research needs to break out of the straitjacket of current diagnosis categories," he says. But like Wessely, he says it is too early to throw away the existing categories.

"These are incredibly complicated disorders," says Owen. "To understand the neuroscience in sufficient depth and detail to build a diagnosis process will take a long time, but in the meantime, clinicians still have to do their work."

David Clark of the University of Oxford says he's delighted that NIMH is funding science-based diagnosis across current disease categories. "However, patient benefit is probably some way off, and will need to be proved," he says.

The controversy is likely to erupt more publically in the coming month when the American Psychiatric Association holds its annual meeting in San Francisco, where DSM-5 will be officially launched, and in June in London when the Institute of Psychiatry holds a two-day meeting on the DSM.