Understanding the association between normal and maladaptive personality traits: Replication and extension of Morey et al. (2020)

Background/Objective: The Alternative Model for Personality Disorders (AMPD) within the DSM-5 includes separable components representing general personality dysfunction (Criterion A) and maladaptive personality traits (Criterion B). Some critique Criterion A for accounting for little incremental variance in PD beyond Criterion B. However, Morey et al. (2020) hypothesized that personality dysfunction is a key mechanism through which normal-range traits account for the maladaptive component of personality traits, justifying its inclusion. We sought to replicate and extend this work in a psychiatric sample with mixed methods. Method: In total, 152 participants recruited from mental health clinics completed multiple measures of personality dysfunction and normal-range and maladaptive traits. Results: Replication was only partially achieved. The degree of incremental prediction of maladaptive traits and the extent to which personality dysfunction explained the relations between normal-range and maladaptive traits varied significantly across traits, and those effects that reached significance were small in magnitude. Removing variance due to personality dysfunction reduced intercorrelations among maladaptive traits by only a small amount. Conclusion: Counter to Morey et al. (2020), our results failed to support maladaptive traits as composites of normal-range traits and personality dysfunction, suggesting that other methods of distinguishing personality pathology severity and style are needed.