Confirmatory factor analysis of the personality disorder subscales from the Inventory of Interpersonal Problems.

The purpose of this study was to identify the best fitting hierarchical factor structure of the subscales for personality disorders developed from the Inventory of Interpersonal Problems (IIP). In earlier work, 5 subscales associated with a diagnosis of personality disorder (PD) had been developed. With data collected from 5 additional samples at 4 sites (N = 1004), relations among the IIP-PD subscales were investigated using confirmatory factor analysis. Several competing models were tested, and a second-order model with 1 second-order factor and 5 first-order factors provided the best fit to the data. The results support the hypothesis of a single latent construct reflecting general personality dysfunction. Measures of this construct may be useful for screening patients into yes versus no PD groups.