Suggestions for a Framework for an Empirically Based Classification of Personality Disorder

BACKGROUND: The classification of personality disorder is one of the least satisfactory sections of contemporary psychiatric classification. Fundamental problems with current classifications include extensive diagnostic overlap, limited evidence of validity, and poor empirical support. METHODS: Conceptual analysis and the results of empirical studies are used to propose a framework for organizing an empirically based classification. RESULTS: First, personality disorder is a form of mental disorder and, therefore, should be classified as a single diagnostic entity on Axis I along with other mental disorders. A preliminary definition of personality disorder as a tripartite failure involving the self system, kinship relationships, and societal relationships is proposed. The evidence suggests that this definition can be translated into a reliable set of items. Second, the diagnosis of personality disorder should be separated from the assessment of clinically relevant personality traits. Given the consistent evidential support for a dimensional model of personality disorder, it is suggested that personality be coded on a set of trait dimensions selected to provide a systematic representation of the domain of behaviours represented by current diagnostic concepts. Third, given that personality traits are hierarchically organized, it is suggested that an axis for coding personality include basic or lower-order dimensions as the primary level of assessment and a few higher-order patterns to summarize information for some purposes. CONCLUSION: A preliminary list of 16 basic dispositional traits is proposed to describe the more specific components of personality disorder based, in part, on the convergence of evidence across studies: anxiousness, affective lability, callousness, cognitive dysregulation, compulsivity, conduct problems, insecure attachment, intimacy avoidance, narcissism, oppositionality, rejection, restricted expression, social avoidance, stimulus seeking, submissiveness, and suspiciousness. Three higher-order patterns were proposed: emotional dysregulation, dissocial behaviour, and inhibitedness, which may occur independently or in combination.