Clinical utility of dimensional models for personality pathology

Clinical utility is defined as the extent to which the DSM assists clinical decision makers in fulfilling the various clinical functions of a psychiatric classification system. Distinction is made between elements of diagnostic validity that are more or less conditional to utility (i.e., coverage, and consistency with etiology and prognosis) and components of clinical utility in the narrow sense of the term (i.e., user acceptability and accuracy, communication, reliability, subtlety, and clinical decision making). Clinical utility is often considered the driving force behind the respective revisions of the DSM system, yet it has been difficult if not impossible to obtain reasonable levels of clinical utility within categorical classifications of personality disorders. This paper presents evidence that a dimensional diagnostic system will substantially improve clinical utility, especially with respect to coverage, reliability, subtlety, and clinical decision making. In addition, some evidence suggests that the purely dimensional models outperform the so-called hybrid models (i.e., dimensional profiling of categories) with respect to coverage, consistency with etiology, subtlety, and clinical decision making. Several research options that might inform future revisions, including the choice or development of a dimensional classification, are suggested.