Comparing Methods for Scoring Personality Disorder Types Using Maladaptive Traits in DSM-5

The DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th ed.) Section III will include an alternative hybrid system for the diagnosis of personality disorder (PD). This alternative system defines PD types partly through specific combinations of maladaptive traits, rather than by using a set of polythetic diagnostic criteria. The current report utilizes a large sample of undergraduates (n = 1,159) to examine three dimensional methods for comparing an individual's trait profile to each PD type. We found that the sum of an individual's scores on the assigned traits obtained large convergent correlations (Mdn r =.61) and best reproduced the patterns of PD discriminant correlations observed within the DSM-IV measure. We also tested the DSM-5 Section III model algorithms and compared them with different thresholds for assigning categorical diagnoses. Frequency rates using the algorithms were greatly reduced, whereas requiring half of the assigned traits produced rates that more closely approximated current prevalence estimates. Our research suggests that DSM-5 Section III trait model can reproduce the DSM-IV-TR PD constructs and identifies effective methods of doing so.