If the potential gains of DSM-V are extremely modest, the potential risks are great and largely unrecognized. Making changes in the diagnostic system is never cheap. Just as with an individual patient, the first consideration in revising the diagnostic classification must always be to “do no harm”—and the harm inflicted by changes in the DSM diagnostic system can come in many, and usually unexpected, forms.
The most obvious cost is the significant burden to the field of having to learn and adapt to any changes included in DSM-V. This will be borne by all clinicians, educators, administrators, and especially mental health researchers.19 Changes that frivolously require new diagnostic instruments (or result in findings that are not comparable over studies and over time) waste money, slow progress, and make it far more difficult to translate research findings into clinical practice. Any “innovations” made in DSM-V should be clear and proven winners or they will not be worth the high overhead cost inherent in any change.
There is also the serious, subtle, and ubiquitous problem of unintended consequences. As a rule of thumb, it is wise to assume that unintended consequences will come often and in very varied and surprising flavors. For instance, a seemingly small change can sometimes result in a different definition of caseness that may have a dramatic and totally unexpected impact on the reported rates of a disorder.20 Thus are false “epidemics” created. For example, although many other factors were certainly involved, the sudden increase in the diagnosis of autistic, attention-deficit/hyperactivity, and bipolar disorders may in part reflect changes made in the DSM-IV definitions. Note this.
This serious unintended consequence occurred despite the fact that careful field testing of the DSM-IV versions of 2 of these disorders had predicted no substantial differences in their rates as measured by DSM-III, DSM-IV, and International Classification of Diseases (ICD)-10 criteria.21,22 The crucial lesson here is that even careful field testing is never completely accurate in predicting what will happen when the system is eventually used in the actual field.
This issue becomes particularly relevant when one considers the skillful pressure likely to be applied by the pharmaceutical industry after the publication of DSM-V. It has to be assumed that they will attempt to identify every change that could conceivably lead to a marketing advantage—often in ways that will not have occurred to the DSM-V Task Force. To promote sales, the companies may sponsor “education” campaigns focusing on the diagnostic changes that most enhance the rate of diagnosis for those disorders that will lead to the increased writing of prescriptions. As I will discuss, there is a great risk of many new “epidemics” based on changes suggested for DSM-V.
This risk is accentuated further by the fact that the field testing for DSM-V will receive no support from the NIMH. The necessary resources will not be available to measure the impact of suggested changes on the reliability and reported rates of diagnoses in the widely varied settings in which DSM-V will be used. In addition, because no DSM-V Options Book or first draft is being produced, the “DSM-V field trials” are not really field trials at all—they are no more than primary data collections that will have little to say about how the final draft of DSM-V will perform in the field. DSM-V decision making regarding changes will therefore be flying fairly blind.
A further problem is that almost everyone responsible for revising the DSM-V has spent a career working in the atypical setting of university psychiatry. This type of clinical experience is restricted to highly select patients who are often treated in a research context. It is a basic tenet of clinical epidemiology that research results and clinical experience derived from tertiary-care settings often do not generalize well when the diagnostic system has to be applied routinely in a more population-based manner.23,24
Unintended consequences are most unpredictable and consequential in forensic settings. Years after the DSM-IV was completed, we learned about the enormous unintended impact of a seemingly slight wording change we made only for technical reasons in the section on paraphilias. A misreading of our intentions in making the change had led to great confusion25—with forensic evaluators using the diagnosis of paraphilia not otherwise specified to justify the sometimes inappropriate lifetime psychiatric commitment of rapists who had no real mental disorder.