Cross post from Neuroskeptic: DSM-5 R.I.P?

From the always excellent Neuroskeptic blog



Yesterday, the proposed new DSM-5 revision of the American Psychiatric Associations “Bible of Psychiatry” came under yet more criticism.

Aaron T. Beck, the father of currently-mega-popular cognitive behavioural therapy, started it off with an attack on the upcoming changes to one diagnosis, Generalized Anxiety Disorder; but many of the points also apply to the other DSM-5 proposals:

The lack of specific features, which is the primary issue for GAD, will not be addressed in DSM-5. The hallmark of the condition will remain pathological worry, although it also characterizes other disorders. Likewise, the proposed behavioral diagnostic criteria lack specificity for GAD, and it is not clear how these will be assessed. The proposed changes will lower the diagnostic threshold for GAD in DSM-5… many currently subthreshold cases will qualify for this diagnosis. The likely inclusion of many such “false-positives” will result in an artificial increase in the prevalence of GAD and will have further negative consequences.

Then from across the Atlantic, and also across the psychotherapy-vs-medication divide, came another piece of criticism. The authors are all associated with the European Medicines Agency (EMA, Europe’s equivalent of the FDA), or with national drug regulators. Although they’re writing in a personal capacity, this is still big news if you ask me.

These authors start out by saying that the EMA is broadly in favour of DSM reform, but they then attack one of the key DSM-5 innovations – the move towards ‘dimensional measures‘ of symptoms in addition to diagnoses:

One of our main concerns is related to potential future [drug] indications based on an effect on a dimension that is independent of diagnostic categories (although we acknowledge that non-specific claims are common in other areas, such as analgesics for pain). As an example, cognitive impairments are common in psychiatric disorders, but they do not have a unique clinical pattern or a unitary cause.

We therefore believe that, at present, such a cross-cutting approach may increase heterogeneity in patient populations and make the assessment of the benefit–risk balance more difficult. Similarly, the use of dimensions as key secondary end points in many different diagnostic categories may lead to pseudospecific indications and polypharmacy. As a general rule, a therapeutic indication should be a well-recognized clinical entity that is clearly distinguishable from other conditions…

They also echo Beck in warning of over-diagnosis and over-medicalization:

Current proposals to reclassify some conditions that were subthreshold or prodromal as distinct syndromes or disorders could have implications for clinical trials. The inclusion of milder or very early cases of psychiatric disorders may lead to an increase in the number of non-disordered (false-positive) patients in clinical trials, and to an increase in the placebo effect, as less severe cases are more likely to respond to placebo. It may therefore be difficult to show a statistically significant difference [of drug over placebo]…

This raises another highly controversial issue: the risk of medicalization of the normal population. In this respect, a strong concern comes from the proposal to remove bereavement exclusion from the criteria for major depressive disorder, implying that all individuals with ‘normal grief’ might be considered as patients in the future.

Regular readers will remember that I’ve covered both overdiagnosis screwing up clinical trials, and the bereavement debate.

Two and a half years ago, shortly after the first draft of the DSM-5 was made public, I predictedthat the eventual release of DSM-5 would be a non-eventbecause, by then, it would have been widely debated and criticized, destroying the illusion of expert consensus that any such document must have in order to succeed.

I think events have borne this out. An awful lot of professionals, patients, and their relatives, will reject the changes in favour of sticking with the DSM-IV or other criteria. Without swift and general acceptance, a document like the DSM is just paper. It seems increasingly likely that the DSM-5 is going to be dead on arrival.

ResearchBlogging.orgStarcevic V, Portman ME, & Beck AT (2012). Generalized anxiety disorder: between neglect and an epidemic. The Journal of nervous and mental disease, 200 (8), 664-7 PMID: 22850300

Florence Butlen-Ducuing et al (2012). DSM‑5 and clinical trials in psychiatry: challenges to come? Nature Reviews: Drug Discovery DOI: 10.1038/nrd3811

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