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Sunday, 24.09.2017

Antonio E. Nardi’s comment on RDoC in Historical Perspective

I read with great enthusiasm your essay on RdoC in Historical Perspective, posted in Perspective on INHN’s website on the 15th of February, 2015. Some of my colleagues and I published in 2013 (Nardi et al., 2013) discussing the difficulties of psychiatric diagnosis and the different points of view nowadays concerning RDoC and DSM-5.
I would like to highlight some ideas presented in that Editorial. For instance, we pointed out that diagnosis in psychiatry has never been an easy task. Every psychiatrist or researcher struggles with diagnostic limitations on a daily basis. The mixture of symptoms, behavior, culture, prejudice and science has always been the subject of the most enthusiastic debate, but with very few results. The release of the Research Diagnostic Criteria (RDC, Feighner et al., 1972), soon followed by the DSM-III, and their diagnostic criteria, brought greater reliability to psychiatric diagnosis, but yielded almost no gains in validity. Many changes for better and for worse were implemented in the subsequent editions of the DSMs. In 2013, the latest edition – DSM-5 - was published. Even though we may criticize some of its aspects and support others, the great development observed in clinical research after the third and fourth editions of the DSM cannot be denied. The main principle of all versions of the DSM is that they are important tools for research and legal work. For clinicians, they serve as guidelines only, and should be no more than that. Clinical practice is an art in which we have to mix science and different levels of philosophy.
Thomas Insel (2013), director of the National Institute for Mental Health (NIMH), published an editorial stating that the greatest provider of funds for mental health research will not accept the DSM-5 as a valid tool for research. This statement creates an uncomfortable situation for the American Psychiatric Association, when the DSM-5 is being presented to the world as the basis for the most modern and reliable diagnoses.
We have the firm point of view that the DSM-5 categories are not supposed to be a perpetual “gold standard.” First, they represent a set of contemporary criteria for an accurate diagnosis that can and will change in the next edition of the manual. Second, the use of DSM-5 does not weaken the Research Domain Criteria (RDoC) project. In fact, the two publications could work together and mutually support each other. Any diagnostic system should be based on emerging research data, but symptom-based categories are what we currently have. We certainly agree with Insel in that research needs to gather genetic, imaging, physiologic, and cognitive evidence in order to improve our understanding of how all biological data - rather than symptoms alone - cluster and how these clusters relate to treatment response. We can already identify some of these issues in the DSM-5. Some new categories may not be sufficiently sound from the scientific point of view. For example, mild neurocognitive disorder, binge eating disorder, and disruptive mood dysregulation disorder are all very close to normal behavior, and we still lack clear cut-off points to improve diagnostic reliability. Some other categories had their formerly strict criteria changed to more open possibilities, and that should be taken very carefully by clinical and research colleagues. No diagnostic classification will address all human needs in this regard, and it must be borne in mind that not all problems in life are caused by mental disorders.
NIMH might orient its research away from DSM categories. According to Insel, patients with mental disorders deserve better. But what could be better than DSM-5 at present? Insel's editorial informs that the NIMH has released the RDoC “to transform diagnosis by incorporating genetics, imaging, cognitive science, and other levels of information to lay the foundation for a new classification system.” The NIMH tried to create a new nosology based on five major systems: 1) negative valence systems; 2) positive valence systems; 3) cognitive systems; 4) systems for social processes; and 5) arousal/modulatory systems. Even though Insel declared that at present we cannot design a system that is based on biomarkers or cognitive performance because we lack the data, symptoms and long-term follow-up is what physicians have available in practice today to support diagnosis. The data required for a precise diagnosis - one that we can really trust - will come in the future, but the patient is suffering now.
The RDoC project is a research framework, not a clinical tool. It is a decade-long project leading perhaps to a better psychiatry, with better diagnosis validity. Working with psychiatric diagnosis means dealing with and searching for all the possibilities to improve future classifications. The RDoC and the DSM are not opposing each each other; they are different pathways by which psychiatry can move to improve diagnosis. Research should be our priority in obtaining data, as research data ultimately, will be the basis to helping people with mental disorders. Physicians should be aware of the limitations of our classifications, but also that they are the best we have at the moment. As for the future, we need robust research data and less fear of challenging psychiatric diagnosis.
References:
1. Nardi AE, Kapczinski F, Quevedo J, Hallak JE, Freire R, Romano-Silva MA. The quest for better diagnosis: DSM-5 or RDoC? Rev Bras Psiquiatr. 2013;35: 109-10.

2. Feighner JP, Robins E, Guze SB, Woodruff RA, Winokur G, Munoz R. Diagnostic criteria for use in psychiatric research. Arch Gen Psychiatry1972; 26: 57-63.
3. Insel T. National Institute of Mental Health: Director's Blog [Internet]. Transforming diagnosis. 2013 Apr 29

Antonio E. Nardi
March 26, 2015