In the past week, I’ve seen some incredibly sensationalistic articles published about the upcoming DSM-5 and a letter recently released by the National Institute of Mental Health (NIMH). In the letter by Dr. Thomas Insel, director of the NIMH, wrote in part, “That is why NIMH will be re-orienting its research away from DSM categories.”
Some writers read a lot more into that statement than was actually there. Science 2.0 — a website that claims it houses “The world’s best scientists, the Internet’s smartest readers” — had this headline, “NIMH Delivers A Kill Shot To DSM-5.” Psychology Today made the claim, “The NIMH Withdraws Support for DSM-5.” (The DSM-5 is the new edition of the reference manual used to treatment mental disorders in the U.S.)
So is any of this true? In a word, no. This is science “journalism” at its worse.
NIMH’s Research Domain Criteria
For the past 18 months, the NIMH has been working on a different categorization system to classify mental disorders, to help further its research efforts (the NIMH is primarily a research-driven organization). It’s called the Research Domain Criteria project:
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.
The proposed classification system works under these 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.
In short, the NIMH is trying to find a new categorization system that takes into account more of the biology, genetics, brain circuitry and neurochemistry that we’ve discovered in the past three decades’ worth of research is becoming increasingly relevant to understanding mental disorders.
Does it Replace the DSM-5?
Will this replace the DSM-5? No, because as Dr. Insel notes, “This is a decade-long project that is just beginning.” If the NIMH effort ever replaces the DSM, it will be a long time from now.
Somehow, though, Science 2.0 and Psychology Today believe this letter suggests the NIMH has “withdrawn” support for the DSM-5, or has delivered a “kill shot” (whatever that is!). Are these kinds of characterizations accurate — or indeed, helpful?
We reached out to Bruce Cuthbert, Ph. D., the director of the Division of Adult Translational Research at the National Institute of Mental Health for clarification.
“As with most shifts in science, changes in research priorities require a transition,” said Dr. Cuthbert.
“Because almost all clinical researchers today grew up with the DSM system both clinically and in research, it will take some time to get a “feel” for the relationships between DSM disorders and various kinds of RDoC phenomena (both in terms of the types of symptoms, and in overall severity), learn how to write grant applications with the new criteria, and evolve new review criteria. So, there will be a period of some time while these crosswalks are worked out.
“I also should point out that these comments reflect [only] our translational research portfolios.
“Our Division of Services and Intervention Research mostly supports research conducted in clinical settings that is relevant to current clinical practice and services delivery. Thus, […] grants in these areas will continue to be predominantly funded with DSM categories for some time.”
That’s a far cry from the entire NIMH withdrawing support for the DSM-5. The NIMH is simply saying (in my opinion), “Look, we’re unhappy with the validity of the DSM and its lack of support for biomedical markers for mental disorders. We’re working on a different schema, especially targeted at researchers. It may have greater relevance someday — that’s our hope and vision.”
Why a New Diagnostic System?
But then again, researchers in mental illness have been promising biomarkers for at least two decades as well — with little notable progress to show for their efforts.1
Why is a new diagnostic system needed?
“For psychiatric disorders, we cannot effectively use very much of the knowledge we have gained about the brain and behavior over the last 30 years because of our symptom-based diagnostic system. In other words, the categories defined by symptoms simply do not map onto all the knowledge that we have gained about brain circuits, genetics, and behavior,” replied Dr. Cuthbert.
“We know that many different mechanisms are involved in any one DSM disorder (heterogeneity), while any one mechanism (fear, working memory, emotional regulation) is typically involved with many different disorders. [This] heterogeneity frustrates attempts to develop new treatments.”
Indeed, as John Horgan over at Scientific American wrote,
Ironically, some pharmaceutical companies that have enriched themselves by selling psychiatric drugs are now cutting back on further research on mental illness. The “withdrawal” of drug companies from psychiatry, Steven Hyman, a psychiatrist and neuroscientist at Harvard and former NIMH director, wrote last month, “reflects a widely shared view that the underlying science remains immature and that therapeutic development in psychiatry is simply too difficult and too risky.”
Pharmaceutical companies say that, on average, a marketed psychiatric drug is efficacious in approximately half of the patients who take it. Dr. Cuthbert from the NIMH suggests that, “One reason for this low response rate is the artificial grouping of heterogeneous syndromes with different pathophysiological mechanisms into one disorder.”
So the NIMH’s regrouping appears to be as much of an effort to spur new drug development as it is an effort to rethink the classification system of mental disorders. Which is a bit odd, if you think about it, since there is a rich research foundation showing that non-medication treatments — such as psychotherapy — work equally well (if not better) for the treatment of many mental disorders.
If these were pure medical diseases with clear and readily defined biomarkers, that shouldn’t be the case. After all, positive thinking can’t cure cancer.2
“Thus, mental disorders are an area where we must transcend the current symptom-based system if we are to advance,” concludes Dr. Cuthbert. “Among other things, if you have to wait until a full-blown set of symptoms is present before you can define a disorder (and there is no quantifiable data regarding risk states, as there is for, say blood pressure), then prevention is — by definition — impossible.”
This is simply untrue, in my opinion. There is a solid and growing research base already demonstrating that we can detect mental illness through a number of early screening and symptom measures and implement prevention measures. Other studies demonstrate significant correlations with certain characteristics — signs that can also be used to implement effective prevention.
“The research process will necessarily involve complex science to understand how we can relate more neuroscience-based measures to more specific and quantitatively-defined symptoms and clinical outcomes,” says Dr. Cuthbert from the NIMH. “This does not necessarily mean, however, that the diagnostic systems of the future will necessitate such a complex battery. As with biomarkers in other areas of medicine, a subsequent phase will be to find assessments that can be obtained feasibly in clinical settings (although this is unlikely to mean, as is the case now, that all disorders can be diagnosed simply sitting in a clinician’s office).”
Is It All About the Money?
Horgan suggests, perhaps, some ulterior motives for NIMH’s statement:
NIMH director Insel doesn’t mention it, but I bet his DSM decision is related to the big new Brain Initiative, to which Obama has pledged $100 million next year. Insel, I suspect, is hoping to form an alliance with neuroscience, which now seems to have more political clout than psychiatry. But as I pointed out in posts here and here on the Brain Initiative, neuroscience still lacks an overarching paradigm; it resembles genetics before the discovery of the double helix.
I’m not as skeptical as Horgan, but do believe the timing of Dr. Insel’s letter is a little curious — right before the launch of the DSM-5, and right after the public commitment of $100 million to brain research.
What is clear is that the NIMH is not withdrawing support for the use of the DSM-5 anytime soon. It is the reference manual all researchers and clinicians use today to speak the same language of mental illness. Without the same reference frame, research — and treatment — would become impossible.
Science 2.0’s article: NIMH Delivers A Kill Shot To DSM-5
- David Kupfer, who chairs the DSM-5 Task Force, told Pharmalot: “The promise of the science of mental disorders is great. In the future, we hope to be able to identify disorders using biological and genetic markers that provide expreciseact diagnoses that can be delivered with complete reliability and validity. Yet this promise, which we have anticipated since the 1970s, remains disappointingly distant. We’ve been telling patients for several decades that we are waiting for biomarkers. We’re still waiting.” [↩]
- Although, to be fair, positive thinking can definitely help in its overall treatment. [↩]