2020 Volume 62 Issue 1 Pages 4-28
The validity of the Five-Factor Model (FFM) of personality for diagnosing personality disorder (PD) was examined in two equivalent PD groups, one with dimensional criteria (N = 246) and the other with categorical criteria (N = 165), selected from 1,088 university students. Both equivalent PD groups did not exhibit specific profiles for each PD on FFM scales of the NEO Personality Inventory-Revised (NEO-PI-R), and multiple regression analyses showed that FFM scores only partly predicted PD, although it was improved by the prototype-matching method. The comorbidity was not different in dimensional and categorical measures of PD. The results suggest that the FFM of personality is useful for providing information about the personality in each individual, but is not very helpful for diagnosing PDs, because each PD does not necessarily exhibit a specific homogeneous trait constellation on FFM based on the NEO-PI-R. Personality trait description and diagnosis of PD are not the same issues. It is necessary to integrate dimensional and categorical approaches to PDs for a more precise classification and diagnosis.
