Factor Structure of the Brief Inventory of Personality Organization and Its Convergence with DSM-5 Personality Disorders

Abstract

The present study aimed to examine the factorial structure of the Brief Inventory of Personality Organization (IPO-30) in an Iranian nonclinical population and to investigate its convergence with DSM-5 maladaptive personality traits and structural personality functioning. This descriptive-correlational study was conducted on 162 participants from the general population, including 47 men and 115 women aged 17 to 66 years. Participants were recruited through convenience sampling and assessed using the Structured Interview of Personality Organization (STIPO), the 30-item Brief Inventory of Personality Organization (IPO-30), and the Personality Inventory for DSM-5 (PID-5). Data were analyzed using descriptive statistics, Pearson correlation coefficients, exploratory factor analysis with oblique rotation, and confirmatory factor analysis using SPSS version 23 and AMOS version 24. Confirmatory factor analysis demonstrated that the original two-factor model of the IPO-30 did not fit the data adequately (χ²/df = 3.28, CFI = 0.549, GFI = 0.563, AGFI = 0.497, RMSEA = 0.119). Exploratory factor analysis yielded a revised 26-item, four-factor structure consisting of Reality Testing, Moral Values, Aggression, and Defense & Identity. These four factors explained a substantial proportion of the total variance and demonstrated satisfactory internal consistency, with Cronbach’s alpha coefficients exceeding 0.70. Furthermore, all extracted personality organization dimensions showed significant positive correlations with all five maladaptive personality trait domains of the PID-5, including Negative Affectivity, Detachment, Antagonism, Disinhibition, and Psychoticism (p < .01), supporting convergent validity. In contrast, correlations between the IPO-derived factors and most STIPO dimensions were not statistically significant, except for a small negative association between the Moral Values factor and the STIPO Moral Values domain (p < .05). The findings indicate that the original two-factor structure of the Brief Inventory of Personality Organization is not fully supported in the Iranian population. Instead, a culturally adapted four-factor, 26-item model demonstrated superior psychometric properties, acceptable reliability, and meaningful associations with DSM-5 maladaptive personality traits.