I think we need to pinpoint your fears. If we can find out what you’re afraid of, we can label it. – Charles Schulz, “A Charlie Brown Christmas”
Lucy, playing psychiatrist to Charlie Brown, reminds us of how the public notes our profession’s focus on description. Her comment was made in 1965, 15 years before the DSM III would turn psychiatric diagnosis on its head by changing from presumed etiology to nosological description of disease. As we require diagnoses for communication, prediction and treatment planning, we still struggle to find the most useful paradigms to achieve these goals.
Though the DSM evolved further to describe syndromes in the DSM V (a shift from the disease concept of DSM III and IV), the limitations of its entirely categorical approach are nevertheless evident. Newer dimensional strategies, though, require validation. Welcome, then, was “A Roundtable Discussion with the Experts on the Future of the DSM — Striving to Remain Relevant to the Field of Psychiatry” on the third afternoon of the 2022 Annual Meeting of the APA in New Orleans. The session explored the integration and harmonization of these two systems as a possible future for psychiatric diagnosis.
Chaired by Nitin Gogtay, MD, and Altha Jeanne Stewart, MD, the panel included Bruce Cuthbert, PhD, Diana Clark, PhD, and Roberto Lewis Fernandez, MD, who all made introductory remarks. Attendees were then divided into focus groups to gather opinions and advice as to how to consider function, currently excluded in DSM, as a dimensional feature in diagnosis. The groups then reconvened to report the results.
Structural features, such as race, ethnicity, economic status and opportunity, affect human development, psychiatric symptoms, categorization and treatment selection will be taken into account in future diagnostic systems. Our current categorical diagnostic system remains — unfortunately — heterogeneous, but dimensional assessment of function divides patients into groupings that are quite novel compared to our usual clinical assessments. As our current clinical language is that of the DSM, dimensionally defined categories often appear unsuitable for clinical understanding, utility and communication. Participants questioned whether dimensional models will be able to identify reliable and clinically useful subgroups within DSM for more targeted treatment than our current, broad categories can point to.
Research Domain Criteria (RDoC), the largest effort to proceed with dimensional research, has its own problem with granularity — how fine you set the criteria for a functional dimension. For example, if we seek to identify and integrate a biomarker into our system, we must define just what it is marking: is it a symptom or a feature of a symptom, as with a marker consistent with a broad term, cognition, or its subcategory, executive function? The more specific, the more granular, and the more difficult to integrate into our current heterogeneous categorical system. Less granularity, however, may limit the utility of this newer approach.
Both presenters and participants identified recent lessons from evolutionary biology as possible solutions to some of these dilemmas. Researchers in this field have recently realized that there is as much variation in “normal” non-problematic behavior as there is in pathological, dysfunctional behavior. They, therefore, now accept a broad range of normality rather than continuing to search for an optimal state. For example, height is measured along a continuum, but in most cases, no particular height is identified as “selected.” A wide variety may exist in the population without consequence. As we consider our labels, can we accommodate more behavioral variations as nonclinical and of no interest for helpful intervention? This might allow us to better identify functions that can be improved through treatment.
As this group considered proceeding with this Herculean task of integrating categorical and dimensional approaches to diagnosis, more than a few participants observed that while RDoC is unknown to many in the profession, even past progressive changes in the DSM may not be adequately adopted throughout our field. One example given was that the age requirement for a diagnosis of Borderline Personality Disorder (18 years of age or older) was removed in DSM-IV in 1994. Yet, it is still frequently used as a criterion by clinicians. No matter what direction psychiatry takes with diagnostic criteria, dissemination, and adoption of any changes would therefore be an additional task to accomplish.
Dr. Putman has no conflicts of interest to declare.
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