About and Beyond Comorbidity: Does the Crisis of the DSM Bring on a Radical Rethinking of Descriptive Psychopathology?

The problem of psychiatric comorbidity is part of a series of difficulties of the current diagnostic system which at once were considered as a consequence of the way the system itself is organized (Aragona 2006). It was then believed that a Kuhnian reformulation of the contemporary debate on the problems of the psychiatric diagnosis was very useful because it allowed clarification in a comprehensive picture of the many rivulets of conceptual research in that field.

In their comments Zachar (2009) and Banzato (2009) seem to agree with my analysis of psychiatric comorbidity (Aragona 2009a) when it stresses that abnormally high frequencies of co-occurrence are to be explained, in important respects, as a consequence of the way mental disorders are operationalized in the Diagnostic and Statistical Manual of Mental Disorders (DSM; also showing the importance of conceptual clarification to deal with this sort of only apparently pure factual problems). On the contrary, they are both unconvinced of the appropriateness and/or fruitfulness of the use of the Kuhnian technical terms and theory in this context.

It could be said that the major aim of the paper was to let clinicians understand the effect of conceptual decisions on what would otherwise seem as a simple empirical finding (in this case, high levels of comorbidity), and that this result seems to be achieved in any case, thus minimizing the importance of a disagreement about the philosophical terms as a pure terminological dispute. Nevertheless, in my work the Kuhnian model had a significant role in the clarification of this matter and it also suggests to the reader a range of possible consequences that are not trivial (Zachar, for example, says to be skeptical about the possibility of a crisis and also about the possibility that a new paradigm could eliminate what I call the comorbidity anomaly). As a consequence, some of the Kuhnian concepts that seemed to be at odds in this context have to be considered in detail to justify my analysis and its consequences. For reasons of space, I avoid a point-by-point reply to all the comments and I concentrate my discussion on three main points. First, I discuss the background of Kuhn's definition of terms such as anomaly and paradigm, as well as my own reasons for using them. In doing so the details of the psychiatric items under study that I wanted to highlight through the use of these philosophical concepts should emerge more clearly. Second, I discuss the problem of having distinguished between artifactual and real comorbidity. Third, I reconsider some of these problems, looking for their implications for future psychopathological research.

Anomalies and Paradigms

Banzato (2009) stresses that comorbidity cannot be a truly Kuhnian anomaly because it is an anticipated side effect of the initial setup of the DSM, and not some unexpected discovery that violates the paradigm-induced expectation. This is a basically correct account of the most known version of Kuhnian anomalies; that is, the tale of some evident nature's failure to conform to clear paradigm expectations, which immediately forces researchers to recognize its importance as a possible source of crisis. However, as is the case for many other Kuhnian terms, he discussed anomalies in several scripts and there are other possible versions of its meaning. In particular, Kuhn (1977, XVII) highlighted that only in very rare cases are anomalies completely unexpected and come out of blue to announce an imminent crisis that leads to a large revolution. More frequently, scientific revolutions are much more smaller, like the discovery of oxygen, and in these cases the process is so gradual that historians find it difficult to say exactly when a discovery was made and who did it. Even in these much smaller cases the usual prelude to changes of this sort is the awareness of anomaly, but here anomalies are not extraordinary events; rather, they are "countless discrepancies between theory and experiment [that] during the course of his career, every natural scientist again and again notices and passes by" (Kuhn...