March 23, 2017

Purdue researchers support new criteria for mental illness categories, diagnosis

WEST LAFAYETTE, Ind. — Three Purdue University psychological sciences professors collaborated with 50 experts in psychology and psychiatry to improve the understanding and diagnosis of mental illness.

The HiTOP, Hierarchical Taxonomy of Psychopathology, was published on Thursday (March 23). “The Hierarchical Taxonomy of Psychopathology (HiTOP): A Dimensional Alternative to Traditional Nosologies” is published online at the Journal of Abnormal Psychology.

“The current categorization of mental illness is not optimal, so this consortium collaborated on a new diagnostic model based on the most current scientific evidence,” says Douglas Samuel, an assistant professor in clinical psychology. “The goal is to help improve diagnosis and treatment, by creating a hierarchy that breaks away from traditional categories, such as major depression, and focuses instead of the common elements and symptoms across a range of mental disorders.”

This ultimate goal of this approach to diagnosis is to help improve the treatment options. Mental illness diagnosis is complex as patients may have somewhat different symptoms, but share the same diagnosis. The HiTOP model aims to improve upon this by more clearly articulating the dimensions of psychopathology.

This initiative was led by Roman Kotov, an associate professor of psychiatry from Stony Brook University. The Purdue team that collaborated on this project also includes Purdue’s Donald Lynam, distinguished professor clinical psychology, and Susan South, an associate professor of clinical psychology.

Professionals use the Diagnostic and Statistical Manual of Mental Disorders as the guideline for diagnosis, and the consortium hopes these new guidelines will be included in the manual’s next update. 

Writer: Amy Patterson Neubert, 765-494-9723,

Source: Douglas Samuel, 

Related website:

College of Health and Human Sciences

The Hierarchical Taxonomy of Psychopathology (HiTOP): A Dimensional Alternative to Traditional Nosologies

The reliability and validity of traditional taxonomies are limited by arbitrary boundaries between psychopathology and normality, often unclear boundaries between disorders, frequent disorder co-occurrence, heterogeneity within disorders, and diagnostic instability. These taxonomies went beyond evidence available on the structure of psychopathology and were shaped by a variety of other considerations, which may explain the aforementioned shortcomings. The Hierarchical Taxonomy of Psychopathology (HiTOP) model has emerged as a research effort to address these problems. It constructs psychopathological syndromes and their components/subtypes based on the observed covariation of symptoms, grouping related symptoms together and thus reducing heterogeneity. It also combines co-occurring syndromes into spectra, thereby mapping out comorbidity. Moreover, it characterizes these phenomena dimensionally, which addresses boundary problems and diagnostic instability. Here, we review the development of the HiTOP and the relevant evidence. The new classification already covers most forms of psychopathology. Dimensional measures have been developed to assess many of the identified components, syndromes and spectra. Several domains of this model are ready for clinical and research applications. The HiTOP promises to improve research and clinical practice by addressing the aforementioned shortcomings of traditional nosologies. It also provides an effective way to summarize and convey information on risk factors, etiology, pathophysiology, phenomenology, illness course, and treatment response. This can greatly improve the utility of the diagnosis of mental disorders. The new classification remains a work in progress. However, it is developing rapidly and is poised to advance mental health research and care significantly as the relevant science matters. 

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