Where’s the Psychology in the Medical Curriculum – and Why does it Matter?

That's rather an extreme blog post title, but was inspired by the APA's (American Psychiatric Association) recent comment that  "Many of the revisions in DSM-5 will help psychiatry better resemble the rest of medicine". This alone would be enough to send shivers down the spine of most psychology-minded mental health practitioners, but it led me to thinking about where that might leave psychology as a rather different knowledge-based approach to understanding and treating mental health problems.

Specifically, if the APA want to impose a medical model on mental health then what will our doctors and physicians be learning about how to deal with their patients with mental health problems? The incremental implications are immense. It is not just that mental health is being aligned with medicine on such an explicit basis in this way, this issue is compounded by the fact that medical training still plays lip service to training doctors in psychological knowledge and, in particular, to a psychological approach to mental health. So has medicine taken the decision to align mental health diagnosis and treatment to fit the constraints of current medical training (rather than vice versa)?

I returned to a President's column I wrote in 2002 about the state of psychology teaching in the UK medical curriculum. The same points I made then seem to apply now. The medical curriculum is not constructed in a way that provides an explicit slot for psychology or psychological knowledge. Even though a recent manifesto for the UK medical curriculum (Tomorrow’s Doctors, 2009) makes it clear that medical students should be able to “apply psychological principles, method and knowledge to medical practice” (p15), there is probably no practical pressure for this to happen. Given that the ‘Tomorrow’s Doctors’ document does advocate more behavioural and social science teaching in the medical curriculum, I suspect that what happens in practice is that a constrained slot for ‘non-core medical teaching’ gets split up between psychology, social science and disciplines such as health economics. If a medical programme decides to take more sociology (because there are sociologists available on campus to teach it) – then there will be less psychology.

The second point I made then was related to the expectations of medical students. This was illustrated by a QAA report for a well-respected medical school. This made the point that:

“...there was a student perception that, in Phase I, the theoretical content relating to the social and behavioural sciences was too large. Particular concern was expressed about aspects of the Health Psychology Module....a number of students suggested that the emphasis placed upon theoretical aspects of these sciences in Phase I was onerous”

Well – death to psychology! My own experience of teaching medical students is that they often have a very skewed perception of science, and in particular, biological science. Interestingly, the ‘Tomorrow’s Doctors’ document advises that medical students should be able to ‘apply scientific method and approaches to medical research’ (p18). But in my experience medical students find it very difficult to conceptualize scientific method unless it is subject matter relevant – i.e. biology relevant. I have spent many hours trying to explain to medical students that scientific method can be applied to psychological phenomena that are not biology based – as long as certain principles of measurement and replicability can be maintained.

But there has been a more recent attempt to define a core curriculum for psychology in undergraduate medical education. This was the report from the Behavioural & Social Sciences Teaching in Medicine (BeSST) Psychology Steering Group (2010) (which I believe to be an HEA Psychology Network group). I am sure this report was conducted with the best of intentions, but I must admit I think it’s core curriculum recommendations are bizarre, and entirely miss the point of what psychology has to offer medicine! It is like someone has gone through a first year Introduction to Psychology textbook and picked out interesting things that might catch the eye of a medical student – piecemeal! For example, the report claims that learning theory is important because it might be relevant to “the acquisition and maintenance of a needle phobia in patients who need to administer insulin” (p30). That is both pandering to the medical curriculum and massively underselling psychology as a paradigmatic way of understanding and changing behaviour!

Medical students need to understand that psychology is an entirely different, and legitimate, method of knowledge acquisition and understanding in biological science. Not all mental health problems are reducible to biological diagnoses, biological explanations or medical interventions, and attempts by the APA to shift our thinking in that direction are either delusional or self-promoting. What is most disappointing from the point of view of the development of mental health services is the impact that entrenched medically-based views such as those of the APA will have on the already introverted medical curriculum. Doctors do need to learn about medicine, but they also need to learn that mental health needs to be understood in many ways – very many of which are not traditionally biological in their aetiology or their cure.

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Criticisms of the DSM Development Process

Another short piece written as a Focus Point for the second edition of my Psychopathology textbook (due to be published late 2013).

DSM regularly undergoes an intensive revision process to take account of new research on mental health problems and to refine the diagnostic categories from earlier versions of the system. One would assume that this would be a deliberate and objective process that could only further our understanding of psychopathology, and that is certainly the intention of the majority of those involved. However, at least some people argue that the process of developing a classification system such as DSM can never be entirely objective, free from bias, or free from corporate or political interests. Allen Frances and Thomas Widiger were two individuals who were prominent in the development of the fourth edition of the DSM, and they have written a fascinating account of the lessons they believe should be learned from previous attempts to revised and develop mental health classification systems (Frances & Widiger, 2012). They make the following points:

1.         Just as the number of mental health clinicians grows, so too will the number of life conditions that work their way into becoming disorders. This is because the proliferation of diagnostic categories tends to follow practice rather than guide it.

2.         Because we know very little about the true causes of mental health problems, it is easier and simpler to proliferate multiple categories of disorder based on relatively small differences in descriptions of symptoms.

3.         Most experts involved in developing DSM are primarily worried about false negatives (i.e. the missed diagnosis or patient who doesn’t fit neatly into the existing categorizations), and this leads to either more inclusive diagnostic criteria or even more diagnostic categories. Unfortunately, experts are relatively indifferent to false positives – patients who receive unnecessary diagnosis, treatment, and stigma – and so are less likely to be concerned about over-diagnosis.

4.         Political and economic factors have also shaped the ‘medical model’ view of psychopathology on which DSM is based, and also contributed to the establishment and proliferation of diagnostic categories. For example, the pharmaceutical industry benefits significantly from the sale of medications for mental health problems, and its profits will be dependent on both (1) conceptions of mental health based on a medical model that implies a medical solution, and (2) a diagnostic system that will err towards over-diagnosis rather than under-diagnosis (see Pilecki, Clegg & McKay, 2011).

Changes in DSM-5

As promised, it's my intention to post some new pieces written for the second edition of my Psychopathology textbook (due to be published late 2013). This post begins that process with a new section written to introduce and evaluate DSM-5 from the Chapter on Classification & Assessment in Clinical Psychology.

"Published in 2013, DSM-5 arguably represents the most comprehensive revision of the DSM so far, and it has involved many years of deliberation and field trials to determine what changes to mental health classification and diagnosis are essential and empirically justifiable (Main chapter headings for DSM-5 are provided in Table 1).

The main changes between DSM-5 and its predecessor (DSM-IV-TR) are listed in Table 2. 

First, previous versions of DSM placed mental health problems on a number of different axes representing clinical disorders (Axis I), developmental and personality disorders (Axis II), or general medical conditions (Axes III). This multiaxial system has been scrapped – largely because there was not enough evidence to justify the differences between them. Instead, in DSM-5 clinicians will be encouraged to rate severity of symptoms along continuums developed for each disorder. Secondly, the importance of some disorder categories has been recognised either by allocating them to their own chapter or by recognising them as new individual diagnostic categories. For example, Obsessive-Compulsive Disorder (OCD) is recognized as a significant mental health problem by being allocated it’s own chapter in DSM-5, and new diagnostic categories within this chapter include Hoarding Disorder (see Chapter 6) and Excoriation Disorder (skin-picking disorder). Similarly, DSM-5 has a new chapter on Trauma & Stress-Related Disorders that now includes Post-Traumatic Stress Disorder (PTSD). DSM-5 focuses more on the behavioural symptoms that accompany PTSD and proposes four distinct diagnostic clusters instead of the previous three. Thirdly, major changes have been made to the criteria for diagnosing Autism Spectrum Disorder (ASD), Personality Disorders, Specific Learning Disorders, and Substance Use Disorders. Autistic Spectrum Disorder has become a diagnostic label that will incorporate many previous separate labels (e.g. Asperger’s disorder, childhood disintegrative disorder, pervasive developmental disorder) in an attempt to provide more consistent and accurate diagnosis for children with autism (see Chapter 16). DSM-5 will retain the categorical model for Personality Disorders outlined in DSM-IV-TR, but rating scales are provided to assess how well an individual’s symptoms fit within these different types (Chapter 12). The new Specific Learning Disorder category is broadened to represent distinct disorders which interfere with the acquisition and use of one or more of a number of academic skills, including oral language, reading, written language or mathematics (Chapter 15), and the new Substance Use Disorder category will combine the previous DSM-IV-TR categories of substance abuse and substance dependence into one overarching disorder. Some other important changes include (1) the elevation of Binge Eating Disorder from an appendix to a recognized diagnostic category, (2) Disruptive Mood Regulation Disorder as a new category for diagnosing children who exhibit persistent irritability and behavioural outbursts, and (3) the removal of the “bereavement exclusion” from the diagnosis of Major Depression; this means that depressive symptoms lasting less than two months following the death of a loved one can be included amongst the criteria for diagnosing Major Depression, and reflects the recognition that bereavement is a severe psychological stressor that can precipitate major depression.

Criticisms of Changes in DSM-5:  While these most recent changes to the DSM have been extensively discussed and researched, many of the revisions have been received critically, and it is worth discussing some of these criticisms because they provide an insight into the difficulties of developing a mental disorders classification system that is fair and objective.

First, many of the diagnostic changes will reduce the number of criteria necessary to establish a diagnosis. This is the case with Attenuated Psychosis Syndrome, Major Depression, and Generalized Anxiety Disorder, and this runs the risk of increasing the number of people that are likely to be diagnosed with common mental health problems such as anxiety and depression. It is a debatable point whether increases in the number of diagnosed cases is a good or a bad thing, but it is likely to have the effects of “medicalizing” many everyday emotional experiences (such as ‘grief’ following a bereavement, or worry following a stress life event), and creating “false-positive” epidemics (Frances, 2010).

Secondly, DSM-5 has introduced disorder categories that are designed to identify populations that are at risk for future mental health problems, and these include Mild Neurocognitive Disorder (which would diagnose cognitive decline in the elderly) and Attenuated Psychosis Syndrome (seen as a potential precursor to psychotic episodes). Once again, these initiatives run the risk of medicalizing states that are not yet full-blown disorders, and could facilitate the diagnosis of normal developmental processes as psychological disorders.

Thirdly, there are concerns that changes in diagnostic criteria will result in lowered rates of diagnosis for some particularly vulnerable populations. For example, applying the DSM-5 criteria for Autism Spectrum Disorder to samples of children with DSM-IV-TR diagnoses that would no longer be available in DSM-5 suggested that 9% of this latter group would lose their autism diagnosis with the introduction of the new DSM-5 criteria (Huerta, Bishop, Duncan, Hus & Lord, 2012). Similar concerns have been voiced about changes to Specific Learning Disorder diagnostic criteria in DSM-5, and the possibility that deletion of the term dyslexia as a diagnostic label will disadvantage individual with specific phonologically-based, developmental reading disabilities (http://www.disabilityrightsohio.org/news/dsm5-dyslexia-june-2012).

Finally, two enduring criticisms of DSM generally that have continued to be fired specifically at DSM-5 have been that (1) DSM-5 has continued the process of attempting to align it’s diagnostic criteria with developments and knowledge from neuroscience (Regier, Narrow, Kuhl & Kupfer, 2011), when there is in fact very little new evidence from neuroscience that helps define specific mental health problems, and (2) most mental health problems (and psychological distress generally) are now viewed as dimensional, so any criteria defining a diagnostic cut-off point will be entirely arbitrary. DSM-5 has attempted to recognise the importance of the dimensionality of symptoms by introducing dimensional severity rating scales for individual disorders. But as we have seen from the discussion above, each iteration change in DSM diagnostic criteria changes the number and range of people who will receive a diagnosis, and this makes it increasingly hard to accept diagnostic categories as valid constructs (e.g. Kendler, Kupfer, Narrow, Phillips & Fawcett, 2009).

Despite its conceptual difficulties and its many critics, DSM is still the most widely adopted classification and diagnostic system for mental health problems. Such a system is needed for a number of reasons, including determining the allocation of resources and support for mental health problems, for circumstances that require a legal definition of mental health problems, and to provide a common language that allows the world to share and compare data on mental health problems. Having said this, there are still many significant problems associated with DSM, and diagnosing and labelling people with specific psychological disorders raises other issues to do with stigma and discrimination. Indeed, we should be clear that diagnostic systems are not a necessary requirement for helping people with mental health problems to recover, and many clinical psychologists prefer not to use diagnostic systems such as DSM-5, but instead prefer to treat each client as someone with a unique mental health problem that can best be described and treated using other means such as case formulation (see Section 2.3 for a fuller description and examples of case formulation)."

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