Examining the alternative model for personality disorder in daily life: Evidence for incremental validity

The alternative model for personality disorders includes a single dimension of personality dysfunction severity (Criterion A) and five dimensions of personality dysfunction styles (Criterion B). Some consider Criteria A and B distinctions redundant, and this appears mostly true in cross-sectional designs. The present research demonstrated that incremental validity can be found when examining personality dysfunction longitudinally. Participants (n = 175) completed a 14-day electronic diary, capturing daily levels of Criteria A and B, along with daily outcomes of personality dysfunction across several domains. Criteria A and B incremented each other across these domains. Moreover, Criterion B trait scores were associated with expected domains of functioning, evidencing convergent and discriminant validity. We discuss the implications for the alternative model for personality disorders, and the usefulness of longitudinal methods to uncover temporal dynamics in personality dysfunction.