Dimensional models for research and diagnosis: a current dilemma

This commentary focuses on the current dilemma regarding the application of dimensional models for research and diagnosis. Four articles are used to review the positive contributions of dimensional approaches. Although categorical approaches are integral in deciding the characteristics of the group to be studied (i.e., development of inclusion/exclusion criteria), the generation of cutpoints for categorical classification is, in reality, working with dimensional data. Ultimately, new methodological strategies need to be incorporated that address both categorical and dimensional aspects of the overall diagnostic framework. These refinements will be vital in determining the extent and reality of co-occurrence of disorder and the determination of boundaries across specific disorders.