Abstract
Recent controversies have illuminated the strengths and limitations of different frameworks for conceptualizing personality pathology (e.g., trait perspectives, categorical models), and stimulated debate regarding how best to diagnose personality disorders (PDs) in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.), and in other diagnostic systems (i.e., the International Classification of Diseases, the Psychodynamic Diagnostic Manual). In this article I argue that regardless of how PDs are conceptualized and which diagnostic system is employed, multimethod assessment must play a central role in PD diagnosis. By complementing self-reports with evidence from other domains (e.g., performance-based tests), a broader range of psychological processes are engaged in the patient, and the impact of self-perception and self-presentation biases can be better understood. By providing the assessor with evidence drawn from multiple modalities, some of which provide converging patterns and some of which yield divergent results, a multimethod assessment compels the assessor to engage this evidence more deeply. The mindful processing that ensues can help minimize the deleterious impact of naturally occurring information processing bias and distortion on the part of the clinician (e.g., heuristics, attribution errors), bringing greater clarity to the synthesis and integration of assessment data.