New approach to diagnosing mental health disorders
An international consortium of psychologists and psychiatrists, including scientists from King’s College London, has developed a new model to help clinicians provide more accurate and useful diagnoses of mental health disorders.
The Hierarchical Taxonomy of Psychopathology (HiTOP) is a classification system of a wide range of psychiatric problems which the researchers hope will be a paradigm shift in how mental illness is diagnosed.
The consortium, comprising Professors Avshalom Caspi, Terrie Moffitt and David Goldberg from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, has published a new research paper on HiTOP, out today in the Journal of Abnormal Psychology.
The HiTOP system has been articulated to address the limitations of DSM-5 (Diagnostic and Statistical Manual), which was published in 2013 and is the standard classification of mental disorders used by mental health professionals across the world.
Diagnosis is important because it defines groups of patients who will receive treatment and public assistance. It is used by drug companies for development of new medications, as well as guiding research efforts overall.
The HiTOP system
First, HiTOP proposes to view mental health as a spectrum. Mental health problems are difficult to put into categories, as they lie on the continuum between pathology and normality, much like weight and blood pressure. Applying an artificial boundary to distinguish what is a healthy behaviour versus mental illness results in unstable diagnoses, as one symptom can change the diagnosis from present to absent. It also leaves a large group of people with symptoms that do not reach the threshold untreated, although they suffer significant impairment.
Second, the HiTOP system simplifies the classification. Currently, there are many overlaps between different DSM-5 diagnoses, with most patients labelled with more than one mental health disorder at the same time. Furthermore, each diagnostic category is so complex that often two patients with the same diagnosis do not share a single symptom in common. The HiTOP solution to these fundamental problems is to classify psychopathology dimensions at multiple levels of hierarchy. This allows doctors and researchers to focus on finer symptom in detail, or assess broader problems, as necessary.
Finally, the HiTOP project adheres to the most up-to-date scientific evidence about the biology underlying mental health, rather than relying on consensus expert opinion. HiTOP effectively summarises information on shared genetic vulnerabilities, environmental risk factors, and neurobiological abnormalities, such as differences in brain activity between patients and healthy individuals.
Find out more about the HiTOP system by reading the full research paper online: Kotov, R et al (2017) The Hierarchical Taxonomy of Psychopathology (HiTOP): A Dimensional Alternative to Traditional Nosologies Journal of Abnormal Psychology.