Issue 10 / 19 March 2012

PSYCHIATRY shares objectives with other medical disciplines, but what should it seek from a diagnostic system?

I’d argue for reliable definition and delineation of a limited set of meaningful clinical disorders well differentiated from “normal” states of psychological distress, and with consideration of probable and evidence-based treatments.

In the 1970s, American psychiatry had lost its way, dominated by psychoanalysis and marginalised within medicine. Its major diagnostic system (Diagnostic and statistical manual of mental disordersDSM-II) provided a “thick descriptive” template (weighting distinctions between high-level domain diagnoses such as schizophrenia, depression and anxiety).

To redress psychiatry’s status and credibility, the “revolutionary” 1980 DSM-III  system sought to reboot psychiatry into medicine by applying “scientific methods” (ie, generating criteria-based diagnoses weighting diagnostic reliability).

Claims by the DSM-III architects (such as it changing the shape of American psychiatry) certainly helped to make the manual successful. Few questioned the methodology (weighting reliability above validity, dimensionalising many diagnostic domains and risking boundary violations with “normal” psychological states), while field trials testing reliability produced some desultory results. For several diagnostic domains, DSM-II was probably better at syndrome definition and distinction than DSM-III.

By dimensionalising clinical depression into major and minor conditions, defined by severity, persistence and recurrence, DSM-III matrices actually allowed more than 200 depressive diagnoses; this alone challenging its utility.

Its most substantive disorder, “major depression”, remains, despite its majesty and gravitas, a pseudo-entity embracing heterogeneous depressive conditions, with the diagnostic bar set low as DSM-III encouraged rating of symptoms “at the lowest order of inference”. Thus, a diagnosis of major depression provides no meaningful information about disorder category, cause or treatment, while it risks capturing grief, sadness and normal depression.

It is salutary to note DSM-III’s architect Robert Spitzer’s 2007 comments that the subsequent “semiofficial prevalence rates that many find unbelievable” reflected DSM’s criteria being derived for research as against community samples.

The latest version — DSM-5 — extends many of these problems, with diagnostic imperialism evident across many domains.  For example, clinical depression is extended further to include diagnostic categories such as “Disruptive Mood Dysregulation Disorder” (temper outbursts) and “Mixed Anxiety/Depression” (when individuals have some depressive symptoms and “trouble relaxing”).

Their underlying dimensional models impose predictable problems in defining cut-offs for “caseness”, while their low severity levels position again the risk of capturing normative states. The boundaries of some gravid psychiatric conditions (eg, schizophrenia) are also stretched to include sub-threshold and pre-clinical states (eg, “Attenuated Psychosis Syndrome”, where a single symptom such as disorganised speech will get many over the diagnostic line and possibly encourage prescription of antipsychotic medication).

All medical practitioners should share current concerns about the DSM-5 hegemony articulated by many senior psychiatrists and community commentators.

As a consequence of its political rather than scientific weighting, it may broaden and help destigmatise the world of psychiatry and encourage the psychologically distressed to seek help. It may (especially in the US) also advance reimbursement of hospital and medical costs, or be used as explanatory or expiative arguments in medicolegal cases.

These are shallow gains, while “costs” risk being substantive. It returns psychiatry to the pathologising world view of the psychoanalysts (ie, everyone has a psychiatric disorder), its derived pseudo-entity categories advance pseudo-profundity, and it informs us little about cause and treatment.

Psychiatry has not been sufficiently destigmatised to withstand some consequences of receiving a formal DSM psychiatric diagnosis. If in doubt, try applying for employment protection or travel insurance and recording that you meet (or ever met) DSM diagnostic criteria for a psychiatric disorder.

Australians have a reputation for sardonic scepticism. This may be a healthy strategy for considering DSM-5.

Professor Gordon Parker is Scientia professor of psychiatry, University of NSW.

Posted 19 March 2012

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2 thoughts on “Gordon Parker: DSM — everyone’s welcome

  1. Duncan Howard says:

    I agree with Gordon Parker’s approach to diagnostic categories, particularly around depression, and the need for more meaningful categories. In general practice we see large numbers of people who could be labelled as suffering from depression experiencing an enormous variety of symptoms, most of which are understandable if one spends a bit of time listening to that person’s experience and life narrative. That they are suffering is not at question, but to lump them all into one category is not helpful, or accurate. Labels can be very helpful, but can also be unhelpful and misleading

  2. Edmond Chiu says:

    Touche! Thanks Gordon for this excellent critique.The DSM (aka Damn Stupid Manual) has its origin in reimbursement with underlying (although unspoken) financial underpinning, having over the years became a document of US psychiatric imperialsm, of less and less relevance to real world clinicians. The increasing pathologising of normal behaviour will bring our discipline into ill repute and create medico-legal minefields to the benefit of the litigious. That lawyers are the rumoured second largest group of purchasers in the US of this document is revealing!

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