The trait-type dialectic: Construct validity, clinical utility, and the diagnostic process

Abstract

The current debate regarding how best to conceptualize, operationalize, and assess personality pathology is often framed as a choice between categorical ("type") and dimensional ("trait") models, but when viewed from the perspective of the diagnostician, these two approaches actually have much in common. It is not possible to assign symptom ratings in any categorical personality disorder framework without first evaluating the severity of each symptom on a continuum, nor to implement dimensional personality disorder assessments in clinical settings without using thresholds that demarcate the presence of personality pathology, or severity of personality dysfunction. Although recent discussions of these two frameworks have focused primarily on issues regarding construct validity (and to a lesser extent, clinical utility), it is important to consider the impact of the diagnostic process as well. When considered within this broader context, the advantages and limitations of each perspective are illuminated, and it becomes clear that the categorical and dimensional frameworks represent an evolving dialectic that will continue into the future, as new and better models alter the focus of these debates.