An alternative model for the diagnosis of personality disorders (PD) was proposed before the publication of the Diagnostic and Statistical Manual of Mental Disorders–Fifth Edition (1). However, the proposed alternative model for personality disorders (AMPD) was rejected as the primary model for diagnosing PDs, and DSM-5 placed this model in its section III– emerging models and measures (2). According to the AMPD, impairments in personality functioning and pathological personality traits characterize PDs. Criterion A refers to disturbances in personality functioning expressed in the domains of self (identity or self-direction) and interpersonal functioning (empathy or intimacy). Criterion B requires an individual to have one or more pathological personality traits based on five-dimensional personality domains, including Negative Affectivity, Detachment, Antagonism, Disinhibition, and Psychoticism (1).
Along with the proposed trait model, Krueger et al. (3) developed a self-report measure for assessing maladaptive personality traits, namely, the Personality Inventory for the DSM-5 (PID-5). The PID-5 is a 220-item self-report measure with a 4-point response scale. It yields 25 primary scales, the combination of which results in five higher-order scales (Negative Affectivity, Detachment, Antagonism, Disinhibition, and Psychoticism). The preliminary psychometric study through exploratory factor analysis showed that the PID-5 factored into five separate trait domains (3). A burgeoning amount of studies have replicated the five-factor model of PID-5 and proposed its appropriate psychometrics properties as well (4–9). A systematic review by Al-Dajani et al. (10) showed that PID-5 enjoys a generally adequate internal consistency and reliability. Also, the acceptable validity of the PID-5 has been reported by examining its association with related external measures (10, 11).
While a majority of studies have investigated the PID-5, there are other alternative forms of the PID-5, including an informant report form (PID-5-IRF), a 100-item Short form (PID-5-SF, 12), and a Brief form (PID-5-BF, 1). PID-5-IRF was introduced to support the self-report measure of PID-5, wherein response bias was a concern. PID-5-SF is the shortened version of PID-5 and includes 100 items. Its factor structure is very similar to the PID-5 (12).
However, the psychometric properties of PID-5-BF that is the main subject of the current study, have been studied less than other alternatives of PID-5. Fossati et al.'s (13) study was among the first few studies to examine the psychometric of the PID-5-BF. While their results replicated the proposed five-factor model for the structure of the measure, one item (Item 11) did not load significantly on the related factor, and several items did not show their largest positive loading on their corresponding expected factors. Notwithstanding, since this study was conducted on adolescents, the results cannot be generalized to the adult population. In another study, Bach et al. (14) examined the psychometric properties of all three PID-5 forms simultaneously in large Danish clinical and community-dwelling samples. The authors found that the three PID-5 forms provided a highly consistent factor structure. Anderson et al. (2) examined the U.S. version of PID-5. Their results yielded an adequate model fit for the five-factor model of the PID-5-BF in the community and combined undergraduate samples. Also, all items loaded to an acceptable degree on their corresponding factors in both samples. The authors suggested PID-5-BF as a screening measure of dimensional maladaptive personality traits.
Overall, the internal consistency of the PID-5-BF and the factors was most often in the acceptable to good range in both community and clinical samples (2, 13, 14). Also, significant associations have been found between PID-5-BF dimensions and related external criterion measures, which support the measure's validity. Negative Affectivity and Detachment domains have been positively associated with indices of internalizing psychopathology (e.g., depression, anxiety, and emotional dysregulation), anger, sensation seeking, and recent experiences of dissociation and negatively with Extraversion and Conscientiousness. Positive small to moderate associations were found between Disinhibition and Antagonism with aggression and alcohol and drug use. Additionally, the Psychoticism dimension of the PID-5-BF showed a strong positive association with depression and emotion dysregulation (15).
Finally, Bach et al. (14) found that PID-5-BF can effectively differentiate psychiatric from community participants and indicated that the PID-5-BF was beneficial in assessing DSM-5's Section II categorical PDs. Similarly, Porcerelli et al. (16) investigated the psychometrics of PID-5-BF in a Primary Care Sample and supported the convergent and discriminant validity of the measure. Accordingly, PID-5-BF can be used as a useful psychiatric screening tool in the primary care setting. Notwithstanding, these studies have been conducted in Western countries, and their results cannot be generalized to the Iranian population.
We found only two studies investigating the factor structure and psychometrics of PID-5-BF in Eastern cultures (17, 18). Untalan (18) studied the psychometrics of PID-5-BF with a Filipino college student sample, and the results did not yield adequate fitness for the five-factor model of the PID-5-BF. Similarly, Zhang et al. (17) found a six-factor model for the structure of the PID-5-BF, which was more applicable than the five-factor model. In the new six-factor model, the Negative Affect domain was divided into two factors with the new factor, namely "Interpersonal Relationships," which was in line with the Big-Six Personality model in China, reflecting the humanistic ethic spirit of Chinese culture (19–21). Since the five-factor model of the PID-5-BF was developed from studies with Western samples, maybe cultural variations underlie different factor structure findings in the Western and Eastern cultures. This reveals discrepancies in how people in Western and Eastern cultures grasp personality constructs and appraise items of the PID-5-BF (17). For instance, the Big-Five Model did not yield a well-fit model in some Asian countries (22–24). Likewise, the Openness dimension of the NEO Personality Inventory was replicated poorly in a study with 24 different Asian cultures, including Iran (25). Eastern cultures (e.g., China and Iran) have a collectivistic culture where group harmony is valued over personal desires and ambitions, and people tend to conform to social expectations (For more information, see 26, 27). Given the role of cultural differences in differing factor structure findings in the literature (e.g., PID-5-BF and NEO), the results from studies on the psychometrics of PID-5-BF in Western countries cannot be generalized to the Iranian population, and a separate study is needed to examine the factor structure, reliability, and validities of the PID-5-BF with Iranian sample.
In the present study, we aimed to examine the psychometric properties of the PID-5-BF with student and clinical samples. More specifically, we examined the internal consistency, factor structure, and discriminant validity of the PID-5-BF. Concerning the factor structure of the PID-5-BF, based on few previous studies (e.g., 2, 13, 14), we expect to replicate the five-factor model solution. Next, to examine the reliability of the Persian PID-5-BF scores, reliability indices, including Chronbach's α and mean inter-item correlation values, will be calculated. Also, to test the validity of the PID-5-BF, we administered NEO-FFI along with the PID-5-BF that have been considered in prior psychometric studies of PID-5 (e.g., 28, 29). Specifically, it is hypothesized that Negative Affectivity and Detachment would be positively related to Neuroticism; and Antagonism, Disinhibition, and Detachment negatively associated with Agreeableness and Conscientiousness (e.g., 28, 29). Finally, discriminant validity is investigated through Student's t-test to examine the ability of the PID-5-BF to score differently in the clinical and student samples.