Research Domain Criteria (RDoC) is a new classification of diseases—nosology-- championed by the U.S. National Institute of Mental Health (NIMH). It was especially promoted by the NIMH then director Thomas Insel. Insel has now migrated to Google Life Sciences which in the Google empire has become a full-fledged member of Mountain View's Alphabet Inc., and taken on a new name: Verily, a for profit health company.
RDoC baptism coincided with the publication of the DSM-5 in 2013, and heralds a radical diagnostic departure by relying exclusively on biomarkers—biological indicators. The implicit assumption being that behavioral/mental/clinical disorders are manifestations of biological/neurological disorders. Bad behavior is nothing more than shorted circuits in the physical system. Finding the bad circuits will fix the problem. The explicit emphasis of RDoC is to “yield new and better targets for treatment.” [1] While demoting the importance of understanding the disease, it elevates the search for a cure. There are emerging criticism of this new nosology [2] [3] [4], but what remains untold, is how RDoC is gaining legitimacy.
RDoC’s biological determinism was promoted by the success of how easy it was for the public and scientists to believe that Alzheimer’s disease was determined by biomarkers. The history of Alzheimer’s disease laid the foundation for a new way of biological determinism that has not been seen since the height of the eugenics movement in 1923 when the American Eugenics Society was founded. But this emphasis on biology is unfounded. There is no evidence that biology exclusively determines Alzheimer’s disease or many other mental disorders. But the illusion was made possible by the acceptance of such an association—that Alzheimer’s disease is purely a neurological disease.
Historically only tenuous evidence separated Alzheimer’s disease from senile (old age)dementia. Alois Alzheimer’s observation—shared by many of his contemporary researchers—was that the biomarkers were not unique either for Alzheimer’s disease or among younger people. But the plaques and tangles were elevated as a unique disease classification by Emil Kraepelin—Alzheimer’s supervisor at the Munich clinic. From its inception, Alzheimer’s disease was promoted as a unique disease because of a context that; 1) promoted biological psychiatry, 2) encouraged competition between Munich and Prague laboratories, 3) the belief that genes and biology determine behavior—eugenics, and 4) ageism, the idea that old age invariably results in diminished capacity but that a similar disease among young people is more noteworthy. These socio-political factors supported the legitimacy of accepting that the plaques and tangles were indicators of Alzheimer’s disease—an association that remains unsupported to this day. RDoC’s new way of biological determinism follows from this illusionary success in defining Alzheimer’s disease as biological. Let’s follow the story further.
The story of Alzheimer’s disease took a new turn in the US with the inception of the National Institute on Aging. The first director of the NIA, Robert Butler—when reflecting on NIA's strategy of emphasizing neurobiological research—confessed that such political machinations reflect the “health politics of anguish.” Politics have been germane to the context of Alzheimer’s disease from the beginning. Although the NIA adopted Alzheimer’s disease as its war banner—a war to get enhanced funding from Congress—for this war to be won, the NIA needed to create a push and a pull. The pull came from creating an epidemic, while the push came from massive public pressure on Congress.
To achieve this "push" the NIA co-opted the mandate of the Alzheimer’s Association—originally the Alzheimer’s Disorder and Associated Dementias—in order to focus on research. In turn the "pull" was created by "creating" an epidemic which pure Alzheimer’s disease could not generate because it was exclusively diagnosed only among a small group of younger adults. So in 1975—in contradiction to Alzheimer, Fischer, Perusini, Bonfiglio, Kraepelin and Pick, who all believed in a dementing disease that afflicted younger adults—the classification of Alzheimer’s disease was singlehandedly, and without consultation, modified to included senile dementia. "We should like to make the suggestion, simplistic as it may be, that we should drop the term 'senile dementia' and include these cases under the diagnosis of Alzheimer's disease" [5] Overnight Alzheimer’s disease subsumed the much larger group diagnosed with senile dementia.[6] Older adults became co-opted in a war for the "pull" of research dollars . The following year this new approach was accompanied by a more detailed study on prevalence [7].
Overnight Alzheimer’s disease became the sixth highest cause of death in the United States, becoming an instant epidemic. With its name—Alzheimer’s disease—came all the attributes of a real neurological disease, while abandoning senile dementia meant dumping the muffled reference to old age. Although this was a shrewd political move it increasingly meant that the meaning of Alzheimer’s disease expanded and broadened, resulting in an increasingly muddled and confused meaning. Such lack of clarity was intentional.
By broadening the meaning, Alzheimer’s disease instantaneously became the king of all dementias. That year, in 1976, Alzheimer’s disease became the most common form of dementia, being diagnosed in over 60% of all dementia cases—followed by Vascular dementia, Dementia with Lewy bodies, Fronto-temporal dementia, Korsakoff syndrome, Creutzfeldt-Jakob disease, and HIV-related cognitive impairment. The rare forms which occur in 5% of cases relate to corticobasal degeneration: Huntington's disease, multiple sclerosis, Niemann-Pick disease type C, normal pressure hydrocephalus, Parkinson's disease, posterior cortical atrophy and progressive supranuclear palsy. Different types of dementias might have different and very specific causes. Arnold Pick saw dementia as “. . . a mosaic of localized partial dementias. . .” [8] Disregarding specificity of dementias, Alzheimer’s disease became the focus for the fight to cure all dementias. It attracted billions of research dollars and captivated an entourage of highly talented researchers, dedicated to advancing biochemical and neurological science.
The ongoing story of how RDoC could have gained momentum came in 2011 when the NIA and Alzheimer’s Association (AA) published the Alzheimer’s disease guidelines. These guidelines created separate stages of the disease from pre-clinical to Mild Cognitive Impairment (MCI), to early and advanced stages of dementia. Although promoted as research guidelines, no suggestions were offered to improve research methodology, identify anomalies, formalize and standardize instrumentation, define MCI, establish causality, develop hypotheses, generate theoretical predictions, discuss and assimilate alternative interpretations, summarize research updates or propose a road map for future research—all recommendations that normally would be expected in research guidelines.
Nevertheless, the guidelines promoted a powerful agenda—but it was a political rather than a research agenda. Despite the lack of evidence for this approach—inherent in the Amyloid Cascade hypothesis [9]—the NIA/AA guidelines effectively allowed the pharmaceutical industry to experiment on a clinical disease before it becomes clinical. To define a behavioral disease by ignoring behavior. To develop guidelines without providing any guidance. This has proved to be a surreal policy experiment. Despite the mounting evidence that the Amyloid Cascade hypothesis is incapable of explaining even the most rudimentary of anomalies, there continues to be a willful promotion to maintain the status quo. The handing of the baton to RDoC will continue this status quo, ignoring accumulating anomalies that contradict biological determinism. But the simplicity of a cure inspires a solitary yearning for a panacea, something which RDoC has explicitly embraced with vigor.
Many opportunities exist to address anomalies in research by broadening the study of Alzheimer’s disease to public health. A public health approach to dementias argues that this disease is not only a neurological or chemical disease but that it is also promoted, mediated and/or moderated by other biological, social and psychological conditions and factors. It is time to confront the encroachment of biological determinism in psychology and aim to navigate a way out of this RDoC diagnostic dead-end.
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[1] Insel T. (2013) Director’s Blog: Transforming Diagnosis April 29, 2013. Accessed on 12/8/2015: http://www.nimh.nih.gov/about/director/2013/transforming-diagnosis.shtml
[2] Nemeroff, C.B., Weinberger, D., Rutter, M., et al. (2013). DSM-5: a collection of psychiatrist views on the changes, controversies, and future directions. BMC Med. 2013;11:202.
[3] Peterson, B.S. (2015) Editorial: Research Domain Criteria (RDoC): a new psychiatricnosology whose time has not yet come. J Child Psychol Psychiatry. 2015;56(7):719-722.
[4] Weinberger, D.R., Glick, I.D., & Klein, D.F. (2015). Whither Research Domain Criteria (RDoC)?: The Good, the Bad, and the Ugly. JAMA psychiatry, 1161-1162.
[5] Katzman, R., & T. Karasu. 1975. Differential Diagnosis of Dementia. In Neurological and Sensory Disorders in the Elderly, edited by W. Fields, 103- 34. New York: Grune and Stratton.
[6] Katzman, R. (1976). The prevalence and malignancy of Alzheimer disease: a major killer. Archives of Neurology, 33(4), 217-218.
[7] Lijtmaer, H., Fuld, P.A., & Katzman, R. (1976). Prevalence and malignancy of Alzheimer disease. Archives of neurology, 33(4), 304-304.
[8] Tilney, F. (Ed.). (1919). Neurological Bulletin: Clinical Studies of Nervous and Mental Diseases in the Neurological Department of Columbia University (Vol. 2). Paul B. Hoeber.
[9] Hardy, J.A., & Higgins, G.A. (1992). Alzheimer's disease: the amyloid cascade hypothesis. Science. 256(5054):184-5.
© USA Copyrighted 2015 Mario D. Garrett
Excerpt from Garrett M. (2015) Politics of Anguish. Createspace.
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