Comparing criterion- and trait-based personality disorder diagnoses in DSM-5

In the recent Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the official personality disorder (PD) classification system remains unchanged. However, DSM-5 also includes an alternative hybrid categorical-dimensional PD system in Section III to spur additional research. One defining feature of the alternative system is the incorporation of a trait model with PD-specific trait configurations, but relatively little work has evaluated how these traits map onto official PD diagnoses or their implications for diagnosis rates. To that end, we compared official PD criteria to Section III PD traits in a sample of current or recent psychiatric patients. We (a) evaluated the extent to which PD traits predicted traditional PD criterion counts, and (b) computed trait-based diagnosis rates and compared them to those reported in several published outpatient and epidemiological samples. Overall, PD traits generally predicted PD criterion counts, but with less than ideal specificity. In addition, we identified differences in diagnosis rates across approaches. These results provide some support for the Section III approach, but they also identify important areas in need of refinement and future study before the field could reasonably switch to a hybrid PD classification approach like that in Section III.