Categorical versus dimensional classification of personality disorders: Are dimensional models the future?

The classification of personality disorders (PD) according to ICD-10 and DSM-IV has been critisized for several reasons. For example, those who have attempted to validate the presence of a nonarbitrary distinction between normal and abnormal personality functioning have suggested that no such distinction exists. Furthermore, PDs frequently co-occur with a number of Axis-I conditions and other Axis-II disorders leading to multiple diagnoses. Therefore, many have suggested classifying PDs dimensionally, rather than categorically. However, there are only a few studies that have investigated the applicability of these models with respect to PDs, and most of these studies used the Big Five. In this study we investigated the applicability of the Seven-Factor model of temperament and character for the classification of PDs. Our results show that the Seven-Factor model discriminates well between PDs and healthy controls, as well as between PDs and Axis-I disorders. We discuss our findings and present a modified scheme to diagnose PDs.