The Validity and Clinical Utility of the Personality Inventory for DSM-5 Response Inconsistency Scale

The Personality Inventory for DSM-5 (PID-5; Krueger, Derringer, Markon, Watson, & Skodol, 2012) is a self-report instrument designed to assess the personality traits of the alternative model of personality disorders (AMPD) in Section III of the DSM-5. Despite its relatively recent introduction to the field, the instrument is frequently and widely used. One criticism of this instrument is that it does not include validity scales to detect potentially invalidating response style, including noncredible over- and underreporting and inconsistent (random) responding. Keeley, Webb, Peterson, Roussin, and Flanagan (2016) constructed an inconsistency scale (the PID-5-INC) to assess random responding on PID-5 and proposed a number of potential cut scores that could be applied. In this study, we attempted to cross-validate the PID-5-INC, including whether the scale could detect randomly generated protocols and distinguish them from nonrandom protocols produced by two student and two clinical samples. The PID-5-INC successfully distinguished random from nonrandom protocols and the best cut scores were similar to those reported by Keeley et al. (2016). We also found that a relatively low amount of random responding compromised the psychometric validity of the PID-5 trait scales, which extended previous work on this instrument.