10/15/14

Psychiatry’s Mythical Phoenix

Prominent research psychiatrists are beginning to sound like their “antipsychiatric” critics. They are saying the current DSM diagnostic system isn’t valid; that something new, something scientifically sound and useful for treating patients is needed. One of these research psychiatrists is Thomas Insel, the Director of the Director of the National Institute of Mental Health (NIMH). He dropped a bombshell last year when he announced that the NIMH would be “re-orienting its research away from DSM categories.” The New York Times quoted Insel as saying: “As long as the research community takes the D.S.M. to be a bible, we’ll never make progress. . . . People think that everything has to match D.S.M. criteria, but you know what? Biology never read that book.”

So the NIMH has developed a new research strategy to classify mental disorders based upon “dimensions of observable behavior and neurobiological measures.” This strategic plan is known as: Research Domain Criteria (RDoC), a framework for collecting data needed for a new nosology. The goal is for RDoC to “transform diagnosis by incorporating genetics, imaging, cognitive science, and other levels of information to lay the foundation for a new classification system.” It was not meant to be a useful clinical tool.

RDoC is in search of the holy grail of psychiatry: reliable biomarkers (measurable indicators of a biological state or condition) for mental disorders. This search for biomarkers has been going on for decades. David Kupfer, the chair of the DSM-5 Task Force said: “We’ve been telling patients for several decades that we are waiting for biomarkers. We’re still waiting.” Susan Kamens suggested that the imminent discovery of biomarkers has been “the driving expectation of psychiatry since its birth in the 18th century.” But there are some problems with the RDoC quest.

What RDoC proposes is to replace the DSM diagnoses used currently to frame mental health research with broad categories based upon cognitive, behavioral and neural mechanisms. This means that the NIMH will be supporting research projects that look across or sub-divide existing DSM categories. But this very same DSM is what is used to assess the potential of future NIMH-funded research under RDoC.

In an article found in Nature, “Psychiatry Framework Seeks to Reform Diagnostic Doctrine,” Nassir Ghaemi said: “It is very hard for people who have been following the DSM their entire professional lives to suddenly give it up.” Ghaemi has felt shackled by the DSM. He wanted to do some research that cut across DSM categories. But his colleagues warned him against straying too far from the DSM structure when he applied for funding from the NIMH, because peer reviewers tended to insist on research structured by the DSM. So he held off from applying.

Steven Hyman, a former NIMH director, blames the DSM for hampering research into the biological or genetic basis of psychiatric illness. He said it was “a fool’s errand” to use symptom-based DSM diagnosis with little basis in nature to try and find a biomarker. Hyman urged the NIMH to think about how biomarkers identified by RDoC would be incorporated into mental health practice with the DSM. “It would be very problematic for the research and clinical enterprises to wake up in a decade to a yawning gulf.”

But Susan Kamens sees a deeper problem with blaming the DSM for hampering the search for biomarkers—it takes for granted that the biomarkers exist. In other words, it presumes what it seeks to find. According to Kamens:

“The main difference is belief versus doubt in the hypothesis that what we call mental disorder is primarily a disorder of biology. We treat that hypothesis as unfalsifiable, as if the proof [that mental disorder is biological] arrived before the evidence. We don’t test whether the hypothesis holds; we test whether and how to make the data fit it. When critics raise doubts, they’re often accused of ignoring the very same evidence that psychiatric researchers have recently declared to be utterly insufficient.”

Kamens noted that the RDoC “blueprint” is no less theoretical that the DSM-5. While the RDoC constructs are more measurable than the categories listed in the DSM, they are “essentially no more than basic human emotions and behaviors.”  She asked how RDoC would make clinically meaningful determinations into its “domains” and “constructs”? How would the research reveal anything beyond the coordinates of normal psychological processes? “In other words, how is RDoC anything beyond basic (nonclinical) neuroscience?”

RDoC is developing a new research model that will undoubtedly yield unprecedented data, but it focuses on the biogenetic correlates and normative mapping of basic psychological processes like visual perception, language, fear responses, and circadian rhythms. The idea is to create interventions for psychological and physiological processes that deviate from the norm. For this reason, RDoC is less likely to save psychiatry than it is to resurrect eugenics.

The quest for biomarkers in psychiatry can be likened to the legend of the phoenix, a mythological bird that repeatedly rises out of the ashes of its predecessor. The DSM seems to be near end of its life-cycle. Now psychiatry is building an RDoC “nest” that it will eventually ignite, reducing both the DSM and RDoC to ashes. And from these ashes, it is hoped, a new diagnostic system—a new phoenix—will arise.

Also see my blog post, “Psychiatry Has No Clothes.”