{"id":28451,"date":"2012-10-06T12:00:18","date_gmt":"2012-10-06T16:00:18","guid":{"rendered":"http:\/\/1boringoldman.com\/?p=28451"},"modified":"2012-10-06T12:00:18","modified_gmt":"2012-10-06T16:00:18","slug":"googlizing-neuroscience","status":"publish","type":"post","link":"https:\/\/1boringoldman.com\/index.php\/2012\/10\/06\/googlizing-neuroscience\/","title":{"rendered":"googlizing neuroscience…"},"content":{"rendered":"
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Words Matter<\/font><\/strong><\/u><\/a>
NIMH Director’s Blog<\/font><\/strong>
By Thomas Insel
October 02, 2012<\/div>\n

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Those who constructed the DSM were looking for a common language to describe symptoms, not a common biology or a common treatment. As someone who entered psychiatry pre-DSM-3, I can attest to the value of a common language. But there have been costs as well. In DSM-4, for instance, the diagnostic criteria for depression require 5 of 9 features, so it would be possible for two people with 1 of 9 criteria in common to have this same diagnosis. Not exactly “precision medicine,” but this approach has delivered diagnostic reliability. What is missing is validity. DSM never presumed to confer validity or explanatory value, but the field has imbued these symptom clusters with biological meaning, perhaps understandable in the absence of biomarkers or diagnostic tests. Ironically, this linguistic oversight has precluded the development of biomarkers that might confer validity. One reason we do not have biomarkers for mental disorders is our presumption that the biomarker is only valid if it maps on to a “fictive category,” rather than developing diagnostic categories based on the experimental data, as proposed by RDoC<\/font><\/u><\/a>, our version of “precision medicine”…<\/strong><\/sup><\/div>\n<\/blockquote>\n
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Research Domain Criteria<\/font><\/u><\/a><\/strong> [RDoC]<\/div>\n

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Strategy 1.4 of the NIMH Strategic Plan calls for the development, for research purposes, of new ways of classifying psychopathology based on dimensions of observable behavior and neurobiological measures. The Research Domain Criteria project [RDoC] has been launched by NIMH to implement this strategy. In brief, the effort is to define basic dimensions of functioning [such as fear circuitry or working memory] to be studied across multiple units of analysis, from genes to neural circuits to behaviors, cutting across disorders as traditionally defined. The intent is to translate rapid progress in basic neurobiological and behavioral research to an improved integrative understanding of psychopathology and the development of new and\/or optimally matched treatments for mental disorders…<\/strong><\/sup><\/div>\n<\/blockquote>\n
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Why has it taken so long for biological psychiatry to develop clinical tests and what to do about it?<\/font><\/strong><\/u>
by Kapur S, Phillips AG, and Insel TR.<\/sup>
Molecular Psychiatry<\/font><\/strong>. 2012 Aug 7. doi: 10.1038\/mp.2012.105. [Epub]<\/div>\n

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Patients with mental disorders show many biological abnormalities which distinguish them from normal volunteers; however, few of these have led to tests with clinical utility. Several reasons contribute to this delay: lack of a biological ‘gold standard’ definition of psychiatric illnesses; a profusion of statistically significant, but minimally differentiating, biological findings; ‘approximate replications’ of these findings in a way that neither confirms nor refutes them; and a focus on comparing prototypical patients to healthy controls which generates differentiations with limited clinical applicability. Overcoming these hurdles will require a new approach. Rather than seek biomedical tests that can ‘diagnose’ DSM-defined disorders, the field should focus on identifying biologically homogenous subtypes that cut across phenotypic diagnosis-thereby sidestepping the issue of a gold standard. To ensure clinical relevance and applicability, the field needs to focus on clinically meaningful differences between relevant clinical populations, rather than hypothesis-rejection versus normal controls. Validating these new biomarker-defined subtypes will require longitudinal studies with standardized measures which can be shared and compared across studies-thereby overcoming the problem of significance chasing and approximate replications. Such biological tests, and the subtypes they define, will provide a natural basis for a ‘stratified psychiatry’ that will improve clinical outcomes across conventional diagnostic boundaries…<\/sup><\/strong><\/div>\n