What harm can DSM-V do?
Elsewhere, I have outlined the 3 harmful unintended consequences that emerged unexpectedly from DSM-I ; namely, a contribution to the false epidemics of autism and attention deficit disorder, and a forensic disaster that has led to the inappropriate psychiatric commitment of sexually violent offenders.4-6 These unpleasant surprises occurred despite the fact that DSM-IV was stubbornly unambitious, discouraged all changes, required extensive empirical documentation, and was widely reviewed by the field at large and by numerous advisors. The risks of unintended consequences from an ambitious, secretive, and poorly organized DSM-V are numerous and significant. My focus here will be only on the ways in which DSM-V may be costly and risky to the research enterprise.
The criteria sets for the most widely studied disorders have been quite stable since the publication of DSM-III in 1980, and indeed since the publication of the Research Diagnostic Criteria in 1978. These DSM criteria sets served as the foundation of the structured and semi-structured interview instruments widely used in all clinical and epidemiologic research. Whenever DSM-V makes a change in a criteria set, this will necessitate that changes be made in the instruments used to assess that diagnosis. Aside from the considerable cost and inconvenience occasioned by such changes, they have the potential to break the highly desirable continuity between the past and ongoing research and all future research findings. The new diagnostic criteria will have untested psychometric performance characteristics and may result in a very different definition of “caseness.” This would make it extremely difficult to interpret differences in findings across time, because the studies will have been done with the different criteria. For example, this apples and oranges problem will greatly complicate the already difficult interpretation of the often radically different rates of mental disorder determined by different epidemiological studies.7-10
A prime example of how far the ambitions of the DSM-V Task Force has exceeded its grasp is its goal to develop and market a set of new interviewing instruments to be used in conjunction with DSM-V.3 While the commercial motivation is understandable, the disruption of methods continuity would be unfortunate, and the costs of switching to a new system of instruments would be prohibitive and wasteful. Moreover, nothing in the work to date by the DSM-V Task Force inspires confidence in its ability to produce and test useful new interviewing instruments, and it would seem to have its hands more than full producing DSM-V itself without needing other distractions.
As I have argued elsewhere, there are serious risks of including a number of prodromal and subthreshold conditions as official diagnostic categories in DSM-V.11-13 The most appealing subthreshold conditions (minor depression, mixed anxiety depression, minor cognitive disorder, and prepsychotic disorder) are all characterized by nonspecific symptoms that are present at extremely high frequencies in the general population. These proposed “disorders” might well become among the most common diagnoses in the general population—particularly once they are helped along by drug company marketing—resulting in excessive use of medications that often have serious long-term complications associated with weight gain. Early case finding is a wonderful goal, but it requires a happy combination of a specific diagnostic test and a safe intervention. Instead, we would now have the peculiarly unhappy combination of a wildly false positive set of criteria with potentially dangerous interventions.
Prospective epidemiological research suggests that DSM-IV is already quite overinclusive.14 Further widening the net would go even further in both medicalizing normality and trivializing psychiatric diagnosis. Altogether, in my view, the costs and risks of the subthreshold diagnoses far outweigh any possible current gains.