The modern DSMs have been fundamentally helpful in psychopathology research. They have provided explicit definitions of categories of psychopathology. The research we reviewed would not have been possible without the foundation provided by these definitions. Nevertheless, the research reviewed here also underlines the value of some evolutionary steps in the field’s conceptualization of psychopathology to further psychological research on the subject.
One evolutionary focus is the DSM
itself. Psychological scientists have important roles to play in pushing for changes to the DSM
. The processes that will eventuate in the publication of the next edition of the DSM
) are just getting underway (see http://www.dsm5.org/
), and there are reasons for optimism regarding the scientific bases for DSM-V
. For example, a number of conferences have been organized to discuss research agendas to help place DSM-V
on solid scientific footing (see, e.g., Widiger, Simonsen, Krueger, Livesley, & Verheul, 2005
, for discussion of a research agenda for personality disorders articulated at one of these conferences).
Yet the DSM is a complex document, shaped in understandable and legitimate ways by considerations that extend beyond psychopathology research per se. To pick a single illustrative example, categories of psychopathology provide labels that are used routinely in facilitating third-party payment for professional services. This record-keeping function of the DSM is conceptually separate from the utility of the DSM as a framework for psychopathology research, but it is no less legitimate. As a result of this understandable multiplicity of influences and purposes, the DSM represents a compromise among diverse considerations.
Such compromises may not optimally serve the needs of the psychopathology research community. As a result, an empirically based model of psychopathology may develop separately from the DSM, to help frame and propel novel research. Some specific steps in developing this kind of model can be gleaned from the current review, and constitute expansions of the conceptual framework represented in . Specifically, it is necessary to better understand the substructure of psychopathology-spectrum concepts such as internalizing and externalizing, and it is also necessary to expand the model beyond these two spectra. This will require developing detailed databases at the symptom level, unconstrained by the a priori assumption that these symptoms are optimally sorted into current DSM categories or sorted by current DSM conventions. For example, close links between personality and psychopathology mean that both sorts of constructs should be covered in such databases. With such data in hand, distinct statistical models corresponding to distinct classification paradigms (e.g., categorical vs. continuous paradigms) can be fit, providing an empirical means of sorting symptoms into syndrome-level constructs and sorting syndromes into broader psychopathology spectra.
In developing such databases, it is also necessary to greatly expand the scope of the model in . The model developed out of attempts to understand the comorbidity (co-occurrence) of the limited subset of DSM disorders that have been the primary focus of epidemiological inquiry; many psychopathology constructs were not included simply because the relevant data do not exist. Expanding the scope of the model requires coverage of a greater diversity of psychopathological symptoms and personality constructs, most likely using samples in which the prevalence of diverse forms of maladaptive behavior is higher than in the community-dwelling population (e.g., treatment-seeking samples).
Such an expanded and more detailed model would logically lead to novel questions in both treatment-oriented and etiologically oriented psychopathology research. With regard to studies of treatment, one could ask if interventions are impacting specific symptoms, specific syndromes, or broad spectra. Parallel questions would emerge in attempting to understand the etiology of psychopathology. For example, do specific genetic polymorphisms (distinct forms of genes) influence details of symptom presentation or overall risk for a broad spectrum of psychopathologies?
The development of this kind of empirically based model of psychopathology—separate from the DSM—might be viewed as unfortunate, in the sense that it might further separate science and practice. Yet it may also be a necessary step in realizing the promise of psychological science as a foundation for developing effective means to alleviate human suffering.