truths to be self evident…

Posted on Tuesday 24 May 2011

After the DSM-III was introduced, people facile with its contents began to "talk funny" [I can’t think of another way to say that]. First, there was a high premium on being able to talk in DSM-ese – using diagnostic terms wherever possible. So instead of "he’s very depressed" they would say "my diagnosis is Major Depression without Psychotic Features." That wasn’t so bad, but there was more. "He has a Major Depressive Disorder and comorbid Generalized Anxiety Disorder" [some would actually say, "MDD with comorbid GAD"]. What that meant was that the depressed person was really anxious. I learned to listen to people talk that way without flinching, because I realized that they were being taught to speak as if these diagnostic categories were nouns, rather than … [I don’t know how to finish that sentence – adjectives or adverbs, maybe]. But comorbid still gets to me, particularly when it’s said with earnestness and emphasis – implying some special meaning. One place it’s tricky is when KOLs use it to suggest reasons to prescribe more medicines – like when they talk about Major Depression being comorbid with medical illness, often implying that depression causes or worsens physical illnesses. Not much science there, particularly since there’s no solid evidence that antidepressants are much help in those situations.  But beside that, there’s something wrong with Major Depression being comorbid with medical illness anyway. It pathologizes being human. It’s depressing to be sick, particularly to be real sick.

I found an interesting article that took a look at this widespread use of the notion of comorbidity in psychiatry:
‘Psychiatric comorbidity’: an artefact of current diagnostic systems?
by Mario Maj

The term ‘comorbidity’ was introduced in medicine by Feinstein (1970) to denote those cases in which a ‘distinct additional clinical entity’ occurred during the clinical course of a patient having an index disease. This term has recently become very fashionable in psychiatry to indicate not only those cases in which a patient receives both a psychiatric and a general medical diagnosis, but also those cases in which a patient receives two or more psychiatric diagnoses. This co-occurrence of two or more psychiatric diagnoses has been reported to be very frequent. For instance, in the US National Comorbidity Survey, 51% of patients with a DSM–III–R/DSM–IV diagnosis of major depression had at least one concomitant anxiety disorder and only 26% of them had no concomitant mental disorder, whereas in the Early Developmental Stages of Psychopathology Study the corresponding figures were 48.6% and 34.8%. In a study based on data from the Australian National Survey of Mental Health and Well-Being , 21% of people fulfilling DSM–IV criteria for any mental disorder met the criteria for three or more concomitant disorders.

This use of the term ‘comorbidity’ to indicate the concomitance of two or more psychiatric diagnoses appears incorrect because in most cases it is unclear whether the concomitant diagnoses actually reflect the presence of distinct clinical entities or refer to multiple manifestations of a single clinical entity. Because ‘the use of imprecise language may lead to correspondingly imprecise thinking’, this usage of the term ‘comorbidity’ should probably be avoided…
I certainly agree with that. The term’s rarely useful, and most often part of a trick. But Dr. Maj went on to say more about it:
A powerful, usually unrecognised, factor contributing to the emergence of the phenomenon of ‘psychiatric comorbidity’ has been ‘the rule laid down in the construction of DSM–III that the same symptom could not appear in more than one disorder’ (Robins, 1994). This rule (never made explicit, to my knowledge, in DSM-related publications), probably explains why the symptom ‘anxiety’ does not appear in the DSM–IV criteria for major depression, although the text of the manual acknowledges that patients with major depression frequently present with anxiety. Lee Robins, the only author who, as far as I know, has mentioned the above rule in the literature, stated: ‘I thought then, as I still do, that the rule was not a good one’. Actually, DSM–IV does not allow the presence of anxiety in a patient with major depression to be recorded either as a symptom or, as allowed for delusions, a specifier for the diagnosis…
Now he’s getting to the point. There’s something fundamentally wrong with the classification that’s being subverted by the term comorbid.
A second, obvious, determinant of the emergence of the phenomenon of ‘psychiatric comorbidity’ has been the proliferation of diagnostic categories in recent classifications. If demarcations are made where they do not exist in nature, the probability that several diagnoses have to be made in an individual case will obviously increase…
"demarcations are made where they do not exist in nature" is quite an indictment. Maj mentions the absence of hierarchies in the new system, but then adds:
…the old clinical descriptions provided a gestalt of each diagnostic entity, which is often not provided by current operational definitions. This was probably due in part to the different emphasis laid on the various clinical aspects (whereas in current operational definitions the various clinical features are usually given the same weight), as well as to the inclusion of some aspects regarded as essential (e.g. autism in the case of schizophrenia) that do not appear in current diagnostic systems because they are regarded as not sufficiently reliable. Traditional clinical descriptions encouraged differential diagnosis, whereas current operational definitions encourage multiple diagnoses, probably in part because they are less able to convey the ‘essence’ of each diagnostic entity. Is this an intrinsic limitation of any operational definition, or a remediable flaw of our current operational definitions? Was the above-mentioned gestalt (for instance, in the case of schizophrenia) a fact or an illusion?…
Dr. Maj’s discussion of the term comorbidity took a turn here that I found very helpful in my own thinking about the DSM-III [etc]. I just don’t like it, not just the individual categories, but the whole "it." I said it was like collecting butterflies in my last post, but it’s more than that, it’s like a color-blind person collecting butterflies.
It feels like it misses a mark in a very fundamental way that I’m not savvy enough to figure out a way to say. Dr. Maj is on a roll here, so I’m just going to include the entirety of his ending:

Most of the recent debate about psychiatric comorbidity has been remarkably atheoretical, focusing on the practical usefulness of one or the other approach in terms of treatment selection and prediction of outcome and service utilisation. However, the emergence of the phenomenon of ‘psychiatric comorbidity’ has obvious theoretical implications. The frequent co-occurrence of the mental disorders included in current diagnostic systems has recently been regarded as evidence against the idea that these disorders represent discrete disease entities. The point has been made that the nature of psychopathology is intrinsically composite and changeable, and that what is currently conceptualised as the co-occurrence of multiple disorders could be better reformulated as the complexity of many psychiatric conditions (with increasing complexity being an obvious predictor of greater severity, disability and service utilisation). From the psychodynamic viewpoint, the idea seems to be reinforced that the interaction of congenital predisposition, individual experiences and the type and success of defence mechanisms employed may generate an infinite variety of combinations of symptoms and signs. From the psychobiological viewpoint, the hypothesis seems to be supported that ‘noxious stimuli . . . perturb a variety of neuronal circuits . . .The extent to which the various neuronal circuits will be involved varies individually, and consequently psychiatric conditions will lack symptomatic consistency and predictability’. From the evolutionary viewpoint, the concept seems to be corroborated that mental disorders are the expression of preformed response patterns shared by all humans, which may be activated simultaneously or successively in the same individual by noxae of various nature – a view endorsed by Kraepelin himself in one of his later works, in which he dismissed the model of discrete disease entities even for dementia praecox and manic–depressive insanity.

However, the emergence of the phenomenon of ‘psychiatric comorbidity’ does not necessarily contradict the idea that psychopathology consists of discrete disease entities. An alternative possibility is that psychopathology does consist of discrete entities, but these entities are not appropriately reflected by current diagnostic categories. If this is the case, then current clinical research on ‘psychiatric comorbidity’ may be helpful in the search for ‘true’ disease entities, contributing in the long term to a rearrangement of present classifications, which may involve a simplification (i.e. a single disease entity may underlie the apparent ‘comorbidity’ of several disorders), a further complication (i.e. different disease entities may correspond to different ‘comorbidity’ patterns) or possibly a simplification in some areas of classification and a further complication in other areas.

There is, however, a third possibility: that the nature of psychopathology is intrinsically heterogeneous, consisting partly of true disease entities and partly of maladaptive response patterns. This is what Jaspers (1913) actually suggested when he distinguished between ‘true diseases’ (such as general paresis), which have clear boundaries among themselves and with normality; ‘circles’ (such as manic–depressive insanity and schizophrenia), which have clear boundaries with normality but not among themselves; and ‘types’ (such as neuroses and abnormal personalities), which do not have clear boundaries either among themselves or with normality. Recently, it has been pointed out that throughout medicine there are diseases arising from a defect in the body’s machinery and diseases arising from a dysregulation of defences. If this is true also for mental disorders – for example, if a condition such as bipolar disorder is a disease arising from a defect in the brain machinery, whereas conditions such as anxiety disorders, or part of them, arise from a dysregulation of defences – then different classification strategies may be needed for the various areas of psychopathology.
Dr. Maj is an internationally renown psychiatrist from Naples Italy who is on the Mood Disorders workgroup for the DSM-V. He is President of the World Psychiatric Association. He has been President of the European Psychiatric Association (2003-2004) and of the Italian Psychiatric Association (2000-2002). He is member of the Italian High Council of Medicine. He’s the author of many books, one entitled Psychiatry as a Neuroscience. But no matter his orientation, he’s a clear thinker, and put his finger on the problems of our diagnostic classification for me – insoluable problems in its current form. It misses the "gestalt" of the conditions we think of as diseases, and it omits the possibility that I think is actually a simple truth at the level of "we hold these truths to be self evident:" "…the nature of psychopathology is intrinsically heterogeneous, consisting partly of true disease entities and partly of maladaptive response patterns."
    May 25, 2011 | 12:53 PM

    As always, excellent work.

    Regarding “DSM-ese” (e.g., “MDD with comorbid GAD”). I agree it’s awkward, but we’ve created a culture in which it’s even more awkward to talk about people as human beings, with genuine symptoms and complaints that don’t fit into any particular “bin.”

    Try walking into a clinical setting and saying something like “he’s quite depressed, and also a little anxious, has some back pain, but has also recently felt more spacey than usual” and you’ll be laughed out of the room. (You also won’t be reimbursed by insurance.) Never mind that this describes the patient far better than “MDD with partial response to SSRI+SNRI, with comorbid GAD features, pain disorder NOS, and r/o psychosis vs cognitive disorder.”

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