A University of Kansas researcher led a large-scale study of undergraduate students to better understand how psychological conditions such as depression, anxiety, post-traumatic stress disorder and eating disorders are linked.
The research, published in the Journal of Psychopathology and Clinical Science, was based on the Hierarchical Taxonomy of Psychopathology (HiTOP), an emerging alternative to the Diagnostic and Statistical Manual of Mental Disorders (DSM), the traditional guide to diagnosing and treating patients.
Findings suggest that the use of symptom dimensions from the HiTOP may better support more accurate, personalized mental health care.
There are problems with the way we diagnose people with mental health problems. The current system is categorical, so you either have the mental health condition or you don’t. This can be really problematic for a number of reasons, and it’s especially true for eating disorders.”
Kelsie Forbush, lead author, professor of clinical child psychology at KU
Forbush also pointed to concerns about the DSM, currently proposed by the American Psychological Association, including the tendency for disorders to be highly heterogeneous.
“There are many ways a person could qualify for a category,” Forbush said. “I think there are 126 different ways that a person can meet the criteria for anorexia nervosa. So, in many cases, that yes or no label doesn’t really tell the clinician or the therapist what’s really going on with a person. It’s also possible that someone with anorexia nervosa and bulimia nervosa may be the same weight, except for shared body symptoms.”
Forbush said two clients can have completely different diagnostic labels but almost identical symptoms. According to the DSM, he added, two people can also be given the same label with little overlap in symptoms.
“We’re also seeing an issue of diagnostic migration over time because of some of these issues,” Forbush said. “For example, we did a study several years ago where we found among people who were diagnosed with anorexia nervosa at first, a year later none of them had the same diagnosis of anorexia nervosa, but they all had an eating disorder.”
Under the DSM’s diagnostic system, Forbush said, small changes in symptom presentation can lead to a different diagnosis. Because of these issues, HiTOP has gained traction.
“People want a system that will be more clinically useful and also convey more information about prognosis,” he said. “That’s another problem we have with the current diagnostic system. When I get the label, I don’t know: Is someone at high risk or low risk? It’s just not very informative that way.”
Alternatively, HiTOP uses dimensional systems instead of diagnostic categories. More specific subdimensions—such as fear, anxiety, and eating pathology—are grouped into broader dimensions.
“These are dimensions instead of categories,” Forbush said. “One way I think about it is if you measure your blood pressure or your weight, it’s a number anywhere in a range. And you can also say, ‘Oh, that’s high blood pressure,’ or ‘that’s a weight that the CDC would say is obesity,’ right?”
Using HiTOP, Forbush and her colleagues develop a hierarchy of symptoms and relationships between symptoms to better understand what a person is experiencing.
“In our previous research, we found that this dimensional system was much more predictive of things like whether someone recovered, their psychiatric disability, and how severe their mental health condition was even a year later,” Forbush said. “Whereas the current system, the DSM, didn’t predict much, even when we looked at multiple disorders together.”
The study used data from a nationally representative sample of veterans collected at KU. All participants were veterans who had separated from their branch of service within the previous six months.
The team analyzed how symptoms clustered and identified “internalizing” as a broad, higher-order dimension that reflects a tendency toward internally directed distress. This hierarchical internalization structure supports HiTOP in DSM-type diagnostic categories.
“I would say that the core of internalizing is a high tendency toward negative emotionality,” Forbush said. “Such high levels of neuroticism—more likely to feel sad, down, anxious, just wired that way. Even negative temperament: some babies come out with more negative temperament than others. That doesn’t mean they’re going to develop disorders, but it makes it more likely. So it’s really about treating that underlying negative emotionality.”
