Content validity of the DSM-IV borderline and narcissistic personality disorder criteria sets.

This study sought to empirically evaluate the content validity of the newly revised DSM-IV narcissistic personality disorder (NPD) and borderline personality disorder (BPD) criteria sets. Using the essential features of each disorder as construct definitions, factor analysis was used to determine how adequately the criteria sets covered the constructs. In addition, this empirical investigation sought to: 1) help define the dimensions underlying these polythetic disorders; 2) identify core features of each diagnosis; and 3) highlight the characteristics that may be most useful in diagnosing these two disorders. Ninety-one outpatients meeting DSM-IV criteria for a personality disorder (PD) were identified through a retrospective analysis of chart information. Records of these 91 patients were independently rated on all of the BPD and NPD symptom criteria for the DSM-IV. Acceptable interrater reliability (kappa estimates) was obtained for both presence or absence of a PD and symptom criteria for BPD and NPD. The factor analysis, performed separately for each disorder, identified a three-factor solution for both the DSM-IV BPD and NPD criteria sets. The results of this study provide strong support for the content validity of the NPD criteria set and moderate support for the content validly of the BPD criteria set. Three domains were found to comprise the BPD criteria set, with the essential features of interpersonal and identity instability forming one domain, and impulsivity and affective instability each identified as separate domains. Factor analysis of the NPD criteria set found three factors basically corresponding to the essential features of grandiosity, lack of empathy, and need for admiration. Therefore, the NPD criteria set adequately covers the essential or defining features of the disorder.