Forget DSM-5 for a Moment; What’s This RDoC?

Last week Dr. Tom Insel, director of the National Institute of Mental Health, made a statement that was interpreted as a warning shot over the bow of the psychiatric community. He said the NIMH would not be using the DSM-5—that is, the latest revision of the Diagnostic and Statistical Manual, which will be released, with much fanfare, later this month—as the basis for research going forward.

This announcement was described in some blogs as the NIMH “abandoning” the DSM, and as “a potentially seismic move.” So…is it? And will it affect families who are living with a psychiatric diagnosis?

Let’s look at what Insel actually said. Essentially, he said that the DSM has been valuable in creating a coherent landscape of mental health diagnosis, but that its categories of disorders do not stem from any measurable causes or underlying biological conditions in the brain. His words (and note that “validity” is a scientific term, not a value judgment):

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.

This isn’t news—the DSM has long been conceived of as an antidote to the often unknown “etiology” or cause of psychiatric illness. Lacking objective diagnostic tests, the manual was intended to create a coherent set of clinical categories so that doctors would be on the same page, and that research into treatments could be compared. Insel’s “abandonment” of the DSM is in fact a symptom of his optimism that we are now or will soon be able to discover the “real,” biological causes of mental illness. And the DSM will be a casualty of this emerging science. “We cannot succeed if we use DSM categories as the ‘gold standard,’” he writes. “The diagnostic system has to be based on the emerging research data, not on the current symptom-based categories.”

If I can summarize Insel’s point: For what we need to do—for what it is becoming clear we can do—the DSM approach is not appropriate. Even if it is still the best way to diagnose disorders and deliver treatment and knit the mental health care system together, it must begin to be supplanted by a framework that will let us apply the science of the future to clinical care.

Insel has one in mind, and the NIMH will be funding research based on a new paradigm called Research Domain Criteria, or RDoC, first mentioned online by NIMH two years ago. “RDoC is a framework for collecting the data needed for a new nosology,” or classification scheme, Insel writes. And “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.”

We have yet to see the effects of the NIMH’s new focus on 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,” as Insel puts it. But in reading back through two years of speculation and opinion on the schism, I came upon a nice quip from Dr. Stuart Kaplan in an article titled “Godzilla Meets Tyrannosaurus Rex?” He writes: “As has been often said, the brain did not read the DSM.” To put this another way: RDoC aims to be what the brain really has to say about its own disorders, dysfunctions, and what causes them. To listen to the brain with proverbial “new ears” of emerging science and to let it dictate new categories and associations that will lead to the new and better diagnostic tools and treatments of tomorrow.

What does this mean for the family in the doctor’s office this weekend? People and families dealing with mental illness have already been made anxious by the possible changes in diagnosis and benefits that may accompany the DSM-5, and more uncertainty—this time from high up in the federal government—can’t be reassuring.

But from what I have read—what Insel has written, what watchers have written in the past two years—what we are seeing is shift towards two different approaches in psychiatry, one focused on clinical expediency, another on the needs of scientific inquiry. In the words of Dr. Nassir Ghaemi in Medscape Psychiatry, the NIMH has decided that we need two sets of diagnostic criteria: “one for practice (DSM-5) and one for research (RDoc). The one for practice can be based on ‘pragmatic’ decisions about diagnostic criteria; the one for research should be ‘real.’”

Vaughan Bell writes on Mind Hacks: “It’s worth saying that this won’t be changing how psychiatrists treat their patients any time soon. DSM-style disorders will still be the order of the day, not least because a great deal of the evidence for the effectiveness of medication is based on giving people standard diagnoses.”

And Insel concludes: “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.”

Only time will tell how these two systems will eventually work together.