How can the DSM-5 alternative model of personality disorders advance understanding of depression?

The DSM-5 introduced an alternative model of personality disorder (AMPD) that includes personality dysfunction plus maladaptive-range traits. This study clarifies relations of depression diagnoses and symptoms with AMPD personality pathology. Two samples (Ns 402 and 601) of outpatients and community-dwelling adults completed four depression (criteria met for major depressive disorder and dysthymia; dysphoria and low well-being scales), ten trait (two scales for each of five domains—negative affectivity, detachment, disinhibition, antagonism, psychoticism), and eight dysfunction (four scales for each of two domains—self- and interpersonal pathology) measures. Diagnoses were made using a semi-structured interview; other measures were self-reports. We quantified cross-sectional relations between depression and personality pathology with correlation and multiple regression analyses. Collectively (median R2; ps < 0.0001), the trait (0.46) and dysfunction (0.50) scales predicted the depression measures strongly, with most predictive power shared (0.41) between traits and dysfunction. However, trait and dysfunction scales altogether predicted depression (median R2 = 0.54) more strongly than either domain alone, ps < 0.0001. Participants with depression diagnoses showed elevations on all nonadaptive trait and personality dysfunction measures, particularly negative temperament/affectivity and self-pathology measures. Generalization of findings to other populations (e.g., adolescents), settings (e.g., primary care), and measures (e.g., traditional personality disorder diagnoses) is uncertain. Cross-sectional analyses did not test changes over time or establish causality. The AMPD is highly relevant to depression. Assessment of personality pathology, including both personality dysfunction and maladaptive-range traits, stands to advance understanding of depression in adults.