Integrating Structure and Function in Conceptualizing and Assessing Pathological Traits

The Diagnostic and Statistical Manual of Mental Disorders' (5th Edition) Alternative Model of Personality Disorders includes a dimensional trait model to describe individual differences in the manifestation of personality pathology. Empirically derived quantitative trait models of psychopathology address many of the structural problems of classical diagnostic schemes (e.g., nonbinary distributions, excessive comorbidity, and diagnostic heterogeneity). However, they are largely based on the structure of individual differences in the manifestation of psychopathology. In contrast, clinical theories of personality disorder, which are the foundation of intervention efforts, are based on the function of maladaptive behavior. This distinction is akin to the difference between morphology and physiology in the broader biological sciences. A structure-function divide in the focus of empirical and clinical work contributes to a lack of integration and difficulties with translation. Here we discuss this tension and argue for the need to bridge this divide and adopt research efforts that integrate structure and function of personality traits. Specifically, we suggest that between-person structure identifies the principal domains of functioning, but to understand dysfunction personality must be conceptualized and studied as an ensemble of contextualized dynamic processes.