E14. Robert Krueger – Empirically-based Diagnosis and Categorisation

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Today we speak with Professor Robert Krueger, Distinguished McKnight University Professor, Hathaway Distinguished Professor, and the Director of Clinical Training in the Department of Psychology at the University of Minnesota. Professor Krueger’s work spans the fields of personality and personality disorders, psychometrics, and genetics, and is centred on developing an empirically-based system of grouping and delineating psychopathology.

This is a topic that I think is important to the way we think about mental health and conduct research into it. And I couldn’t hope to have to have a more qualified guest to discuss the topic with. Professor Krueger was a member of the DSM-5 Personality and Personality Disorders Work group, and is an architect of the Hierarchical Taxonomy of Psychopathology a new, dimensional classification system of psychiatric problems.

Show Notes

1:20 – On Robert’s background

2:55 – On the problems associated with the DSM diagnostic procedure

5:05 – How did we end up with the DSM given how readily the associated problems are observed, and given the transdiagnostic approach of early psychotherapists?

8:20 – On the pendulum swinging back the other way now.

11:50 – An outline of the HiTOP (Hierarchical Taxonomy Of Psychopathology) approach to diagnosis and categorisation.

17:20 – On why traditional categorical diagnoses appear in the HiTOP?

22:25 – On the similarities and differences of Research Domain Criteria (RDoC)

26:40 – On other approaches to deriving an empirically derived nosology, apart from HiTOP and RDoC.

28:55 – Will the shift to an empirically derived nosology be a big change for clinicians?

33:20 – Thinking about an example involving multiple diagnoses, from a HiTOP perspective.

37:15 – Does the move toward an empirically derived nosology have any implications for debates around the over-pathologising of normal human experience?

41:00 – What advice does he have for students?

2:00 – On Robert’s background

Robert was trained as a clinical psychologist, obtaining a PhD in clinical psychology. His interest in diagnosis and categorisation goes back to early experiences struggling to apply the standard diagnoses to his clients.

2:55 – On the problems associated with the DSM diagnostic procedure

Under the DSM, diagnoses are made when someone meets a certain threshold of diagnostic criteria from a list of diagnostic criteria. Under this system there can be considerable heterogeneity within categories (people with different symptoms receiving the same diagnosis). Similarly, people tend to meet the criteria for more than just a single diagnoses. This is known as the co-morbidity problem, and limits the usefulness of a diagnosis for planning appropriate treatments.

5:05 – How did we end up with the DSM given how readily the associated problems are observed, and given the transdiagnostic approach of early psychotherapists?

DSM-3, published in 1980, was a significant turning point. Earlier editions of the DSM had only descriptive paragraphs instead of well delineated criteria sets (which was also problematic). It is only by doing research with such criteria sets that their problems clearly emerge.

8:20 – On the pendulum swinging back the other way now.

Robert identifies the main reasons why people in the research community are supportive of a move  to a more empirical diagnostic system as due to the disappointing search for biomarkers of psychiatric conditions. For clinicians, it is the lack of informativeness of a diagnosis for planning appropriate treatments.

11:50 – An outline of the HiTOP (Hierarchical Taxonomy Of Psychopathology) approach to diagnosis and categorisation.

HiTOP is an effort to follow the evidence of how the symptoms associated with psychiatric conditions are organised. The resulting view is one where people’s experience is seen to fall along different dimensions, rather than in clearly different categories. The dimensions are considered to be organised hierarchies from signs and symptoms at the lowest level to a general psychopathology factor at the highest level.

17:20 – On why traditional categorical diagnoses appear in the HiTOP?

The presence of traditional categorical diagnoses in HiTOP, such as Major Depressive Disorder and Bipolar Disorder, partially reflects that fact that most research has been done along the line of such categories. However they are also intended to help with the transition from the current approach to an empirical approach.

In time, the use of such diagnoses may fall away if such a change was supported by the evidence.

22:25 – On the similarities and differences of Research Domain Criteria (RDoC)

The RDoC project is an initiative being developed by US National Institute of Mental Health. It was initiated in response to the same dissatisfactions with the DSM criteria that motivated HiTOP. However, in comparison with HiTOP, RDoC is more focused on biological mechanisms and makes less concessions to ensure continuity and an easy transition from the current approach.

RDoC and HiTOP should be seen less as competing approaches, and more as complementary approaches that will dialogue and converge on a consensus conception of psychopathology.

26:40 – On other approaches to deriving an empirically derived nosology, apart from HiTOP and RDoC.

There are a variety of approaches currently being explored with the hope of deriving an empirically derived nosology. Network approaches focus on the relationship between different symptoms. A key difference between network approaches and HiTOP is that network approaches don’t give much focus to higher levels of the hierarchy proposed by HiTOP.

28:55 – Will the shift to an empirically derived nosology be a big change for clinicians?

In some ways, especially around record-keeping and insurance, the move to a HiTOP-type system may require significant changed. But in terms of how they think about and approach treatment, clinicians may already operate in a way that is consistent with a HiTOP-type system. For example, they may often forego a formal diagnostic assessment as they consider it to have little clinical utility. Instead, they may think about their client’s difficulties in broader terms than DSM-5 labels, something like the HiTOP spectra (internalising, externalising and thought disorders).

33:20 – Thinking about an example involving multiple diagnoses, from a HiTOP perspective.

The example involved a case where a person presents with symptoms of anxiety, depression and substance-use disorder. There is little difference in the way one would approach treatment (again, testament to the fact that most clinicians don’t use DSM-5 diagnoses to guide treatment).  However, a notable opportunity that comes from thinking in a HiTOP-consistent way, is to identify processes that are relevant to a number of diagnostic categories.

37:15 – Does the move toward an empirically derived nosology have any implications for debates around the over-pathologising of normal human experience?

For one thing, efforts to derive an empirically derived nosology have highlighted that there is no bright line between psychopathology and normal variation. This spectrum-based thinking, instead of categorical thinking, highlights that it is convention that dictates when to intervene, rather than a simple case a disease is present and therefore an intervention is warranted/necessary.

41:00 – What advice does he have for students?

Pursue your passion. This might seem cliche, but for Robert, doing something meaningful and interesting makes it easier to persist through the difficult times.

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Announcements

There is currently an opportunity to volunteer as a research assistant with the Black Dog Institute. They are particularly after volunteers who can visit Walcha and/or Glen Innes (travel costs reimbursed), though opportunities exist in other areas of New South Wales too. The positions will support The Future Proofing Study, which is the largest mental health prevention study ever undertaken in Australia. I spoke with the Chief Investigator of The Future Proofing Study in Episode 10 (https://www.mindstewpodcast.com/e010/). Details of the position can be found here.