Clinical Psychology Review, Vol. 20, No. 7, pp. 823–851, 2000 Copyright © 2000 Elsevier Science Ltd Printed in the USA. All rights reserved 0272-7358/00/$–see front matter PII S0272-7358(99)00014-8 823 ISSUES IN THE ASSESSMENT AND CONCEPTUALIZATION OF PERSONALITY DISORDERS Richard F. Farmer Idaho State University ABSTRACT. This article reviews several current issues associated with the definition and as- sessment of personality disorders (PDs) as defined in the third and fourth editions of the Diagnos- tic and Statistical Manual of Mental Disorders (DSM). Specifically reviewed are issues associ- ated with classification, PD conceptualizations, and the assessment of these disorders. DSM PD categories are also reviewed in terms of their psychometric properties. A review of the PD assess- ment literature suggests that DSM conceptualizations and definitions of PDs are problematic at both conceptual and quantitative levels. This article concludes with suggestions for possible alter- native approaches to and modifications of DSM PD assessment. © 2000 Elsevier Science Ltd KEY WORDS. Personality, Personality Disorders, Assessment, DSM. THE FORMAL RECOGNITION of the clinical relevance of personality disorders (PDs) in the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III; American Psychiatric Association, 1980) two decades ago stimulated consid- erable scholarly interest in these conditions. Emerging research on the assessment and conceptual aspects of DSM PD categories, however, is beginning to suggest that these concepts are problematic on several levels. This article reviews the empirical status of DSM-based PD assessment. In the context of this review, pertinent issues related to classification and theory, PD definitions and description, and the reliability and validity of PD assessment are discussed. The DSM classification approach is also contrasted with alternative approaches, most notably quantitative and theory-based approaches. Discussion of these areas culminates in sug- gestions for possible modifications in the definitions and conceptualization of PDs as a means of improving the quality of PD assessment. Correspondence should be addressed to Richard Farmer, Department of Psychology, Idaho State University, Pocatello, Idaho, 83209-8112; E-mail: farmrich@isu.edu