Personality disorder assessment: the challenge of construct validity.

We begin with a review of the data that challenge the current categorical system for classifying personality disorder, focusing on the central assessment issues of convergent and discriminant validity. These data indicate that while there is room for improvement in assessment, even greater change is needed in conceptualization than in instrumentation. Accordingly, we then refocus the categorical-dimensional debate in assessment terms, and place it in the broader context of such issues as the hierarchical structure of personality, overlap and distinctions between normal and abnormal personality, sources of information in personality disorder assessment, and overlap and discrimination of trait and state assessment. We conclude that more complex conceptual models that can incorporate both biological and environmental influences on the development of adaptive and maladaptive personality are needed.