A framework for integrating dimensional and categorical classifications of personality disorder

Although empirical evidence strongly supports a dimensional representation of personality disorder, there is strong resistance to dimensional classification due in part to concerns about clinical utility. Acceptance of an evidence-based dimensional classification would be facilitated by information on how such a system would map onto existing diagnoses. With this objective in mind, an integrated framework is proposed that combines categorical and dimensional diagnoses. A two-component classification is adopted that distinguishes between the diagnosis of general personality disorder and the assessment of individual differences in the form the disorder takes. Then, the DSM definition of personality disorders is extended by defining individual disorders as categories of trait dimensions. This makes it possible to develop an integrated classification organized around a set of empirically derived primary traits. Assessments of these traits may then be combined to generate categorical and dimensional diagnoses. It is argued that this approach would introduce an etiological perspective into the classification of personality disorder and improve categorical classification by providing an explicit definition of each diagnosis. The clinical utility of incorporating a dimensional classification is discussed in terms of convenience and acceptability, value in predicting outcomes and treatment planning, and usefulness in organizing and selecting interventions.     

Alternative dimensional models of personality disorder: finding a common ground

The recognition of the many limitations of the categorical model of personality disorder classification has led to the development of quite a number of alternative proposals for a dimensional classification. The purpose of this article is to suggest that future research work toward the integration of these alternative proposals within a common hierarchical structure. An illustration of a potential integration is provided using the constructs assessed within existing dimensional models. Suggestions for future research that will help lead toward a common, integrative dimensional model of personality disorder are provided.     

Personality disorder research agenda for the DSM-V

The American Psychiatric Association is sponsoring a series of international conferences to set a research agenda for the development of the next edition of the diagnostic manual. The first conference in this series, "Dimensional Models of Personality Disorder: Etiology, Pathology, Phenomenology, and Treatment," was devoted to reviewing the existing research and setting a future research agenda that would be most effective in leading the field toward a dimensional classification of personality disorder. The purpose of this article, authored by the Steering Committee of this conference, was to provide a summary of the conference papers and their recommendations for research. Covered herein are the reviews and recommendations concerning alternative dimensional models of personality disorder, behavioral genetics and gene mapping, neurobiological mechanisms, childhood antecedents, cross-cultural issues, Axes I and II continuity, coverage and cutoff points for diagnosis, and clinical utility.     

An empirically-based classification of personality disorder

An empirically-based classification is proposed based on studies of the phenotypic structure and genetic architecture of personality disorder. The proposed system has two parts: (1) a definition of general personality disorder, and (2) a system for diagnosing different forms of disorder. General personality disorder is conceptualized as a pervasive disturbance in the overall structure and organization of the personality system that is manifested as the failure to establish a coherent self-system and the capacity for adaptive interpersonal and social behavior. Different forms of disorder are represented by a dimensional system consisting of 30 primary traits organized into four higher-order domains. The system is intended to offer a systematic and comprehensive diagnosis of personality disorder for clinical and research purposes. It is also intended to be used in a flexible but prescribed way to provide a diagnostic assessment tailored to different assessment needs.     

The DSM-III-R Categorical Personality Disorder Diagnoses: A Critique and an Alternative

Thepurpose of this article is to review the Diagnostic andStatistica1 Manual ofMental Disorders (DSM-III-R; American Psychiatric Association, 1987) categorical diagnosis of personality disorders and to provide an alternative. The results from a variety of studies indicate that the categorical distinctions provided in DSM-ZII-R lack empirical support and that a dimensional model of classification would provide more reliable and valid assessments of personality disorder. The arguments favoring the categorical model--familiarity, tradition, simplicity, ease, and consistency with clinical decisions-are also addressed An alternative approach based on the five-factor model of personality is presented. Two concerns regarding this model are the relevance of the openness-to-experience dimension and the differentiation of abnormality from normality, but neither concern is problematic when personality disorders are understood to be maladaptive variants of normal personality traits.     

Important questions remain to be addressed before adopting a dimensional classification of mental disorders

Comments on the original article "Plate tectonics in the classification of personality disorder: Shifting to a dimensional model," by T. A. Widiger and T. J. Trull. Widiger and Trull raised important nosological issues that warrant serious consideration not only for the personality disorders but for all mental disorders as the Diagnostic and Statistical Manual of Mental Disorders (DSM) is revised during the next few years. As argued compellingly by these authors, dimensional classification may indeed offer substantial improvement over the present categorical system. Several questions remain to be addressed in evaluating whether this is the case and, if so, how dimensional classification can be implemented to best serve the disparate users of the DSM.     

人格行为遗传学研究的两类取向

随着行为主义衰落和生物学技术发展,长期遭受“冷遇”的人格行为遗传学研究近些年成为颇受关注的领域,并由数量遗传学取向发展到分子遗传学取向.数量遗传学取向主张运用双生子研究、收养研究等设计来估计群体中遗传因素对人格表现型方差的贡献率,在人格特质、人格障碍、态度与偏好等人格方面做了大量研究.分子遗传学取向主张在DNA水平上用基因测定方法研究特定基因对人格表现型的影响效应,着重从多巴胺、5-羟色胺和去甲肾上腺素三种神经递质路径考察了基因与人格的关系.未来研究要强调在数量遗传设计中加入对特定基因型的直接测量,注重多学科和多范式的有效整合,扩大对健康人群积极人格品质的研究,加强基因对人格的深层作用机制研究和分子医学层面的人格干预研究.     

Changing Ideas About the Treatment of Borderline Personality Disorder

Systematic treatment outcome studies and research on the structure and origins of the disorder are challenging many traditional ideas about the nature and treatment of borderline personality disorder. On the basis of this research, it is argued that a comprehensive treatment requires an eclectic approach that uses an array of interventions drawn from different therapeutic models that are delivered in an integrated and coordinated way. Such an approach conceptualizes treatment in terms of generic strategies designed to build an effective alliance and treat core self and interpersonal pathology and specific interventions to treat the various components of the disorder. It is also argued that there may be limits to the extent to which some aspects of borderline pathology can be changed. Borderline personality disorder is often a chronic condition that is best managed using a rehabilitation model.     

Commentary on reconceptualizing personality disorder categories using trait dimensions

The ability of trait models of personality to account for categories of personality disorder is examined with particular reference to the five-factor approach. Although dimensional models are consistent with the evidence, and trait models can accommodate personality disorder categories, it is not clear that such models are directly applicable to clinical use. The lower-order or facet structure, in particular, needs further development to capture clinical concepts. It is also suggested that trait models do not account for all aspects of personality disorder-attention also needs to be paid to the organizing and integrative functions of personality.     

Judgment research and the dimensional model of personality

Comments on the original article "Plate tectonics in the classification of personality disorder: Shifting to a dimensional model," by T. A. Widiger and T. J. Trull. The purpose of this comment is to address (a) whether psychologists know how personality traits are currently assessed by clinicians and (b) the reliability and validity of those evaluations. Although Widiger and Trull argued that the shift to a dimensional model will improve the diagnosis of personality disorders, we can also expect that it will lead to improvements in evaluating personality traits.     

Geology 102: More Thoughts on a Shift to a Dimensional Model of Personality Disorders

The classification of personality disorders is at a critical stage. The categorical model presented in the official diagnostic manual of mental disorders has serious limitations, and it is time for a shift to a dimensional model of personality disorder. Although the evidence in favor of switching to a dimensional model of personality disorder is compelling, the fields of clinical psychology and psychiatry have been reluctant to make the shift. We think some of this reluctance is due to a misunderstanding of the current state of dimensional models of personality and personality disorders. We address three major myths about dimensional models and provide responses to each.     

The DSM-5 dimensional model of personality disorder: rationale and empirical support

Ideally, a dimensional model of normal and abnormal personality functioning within the forthcoming DSM-5 would represent a common ground among the existing alternative models and would be consistent with the substantial body of empirical research that has accumulated on such models. The DSM-5 Work Group had the opportunity to make an historic step toward the integration of the normal personality traits researched within psychology with the personality disorders of psychiatry. They chose instead to construct a cumbersome six-dimensional model of personality disorder that excludes normal personality traits, is inconsistent with the preponderance of the research, and is distinguished explicitly from the predominant dimensional model of general personality structure.     

An Overview of Issues Related to Categorical and Dimensional Models of Personality Disorder Assessment

Despite long-standing efforts to improve the current diagnostic system for Axis II, problems remain with the categorical conceptualization of personality disorders (PDs). Due in part to these problems, interest has developed in dimensional models of PD classification. In this article, we discuss four issues relevant to categorical vs. dimensional assessment of PDs: (a) problems with self-reports in PD patients, (b) methodological issues in behavioral and clinician assessment of PDs, (c) challenges that arise when dimensional models are applied to patient and nonpatient samples, and (d) clinical implications of categorical and dimensional PD models. We suggest that researchers and clinicians address these concerns to avoid implementing a new PD assessment model that—although different from the current system—would otherwise remain fraught with difficulties.     

Dimensional versus categorical classification of mental disorders in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders and beyond: comment on the special section

The value of including dimensional elements in the Diagnostic and Statistical Manual of Mental Disorders (DSM) has been recognized for decades. Nevertheless, no proposals have been made for introducing dimensional classification in the diagnostic system in a valid and feasible manner. As an initial step in this endeavor, the authors suggest introducing dimensional severity ratings to the extant diagnostic categories and criteria sets. Although not without difficulties, this would begin to determine the feasibility of dimensional classification and would address some limitations of the purely categorical approach (e.g., failure to capture individual differences in disorder severity, and clinically significant features subsumed by other disorders or falling below conventional DSM thresholds). The utility of incorporating broader dimensions of temperament and personality in diagnostic systems beyond the fifth edition of the DSM is also discussed.     

The person as co-investigator in personality research

In this paper, arguments are presented for considering the subject as co-investigator in personality research. A review of current research methods suggests that personality psychology is well on its way to recognizing the individual as an expert on his or her own self and situation. This means that the subject should also be allowed to take a much more active role in psychological research. It is argued that the ideal methodology for accomplishing this integration of the individual into psychological research is to establish a dialogue between psychologist and subject, allowing each to contribute to the scientific process from his or her own perspective and on the basis of his or her own expertise. The present approach calls for greater emphasis on the organization and coherence of personality as a system, greater openness and sensitivity to the particular world of the individual, and an even more dynamic conception of individuality than is currently found in our field. An important implication of the open system approach advocated in this article, the reduced role of prediction in personality research, is discussed and, finally, a preliminary list of expected gains and losses is presented.     

Plate tectonics in the classification of personality disorder: shifting to a dimensional model

The diagnostic categories of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders were developed in the spirit of a traditional medical model that considers mental disorders to be qualitatively distinct conditions (see, e.g., American Psychiatric Association, 2000). Work is now beginning on the fifth edition of this influential diagnostic manual. It is perhaps time to consider a fundamental shift in how psychopathology is conceptualized and diagnosed. More specifically, it may be time to consider a shift to a dimensional classification of personality disorder that would help address the failures of the existing diagnostic categories as well as contribute to an integration of the psychiatric diagnostic manual with psychology's research on general personality structure.     

Personality disorders in offenders: categorical versus dimensional approaches.

The present study focused on the consequences of cut-off scores in personality disorder diagnoses for their association with criminal behavior. Using ICD-10 personality disorder criteria eliminating offence-related symptoms, we studied the distributions of categorically diagnosed personality disorders and of dimensional personality disorder scores in a group of offenders and a noncriminal control group. Whereas the dimensional scores of the offender group differed significantly from those of the control group for all personality disorders under study, the frequency of categorical diagnoses differed significantly for two personality for two personality disorders only. Moreover, prediction of group membership (offenders vs. nonoffenders) from personality disorder scores was substantially more precise than prediction from categorical diagnoses. It is concluded that a dimensional approach to personality disorder diagnosis is not only superior theoretically but also yields more precise information about the specific associations with criminal behavior.     

An Evaluation of Behavioral Approach in Adults with ADHD

Motivational models emphasizing altered reinforcement sensitivity have been increasingly implicated in etiological accounts of attention-deficit/hyperactivity disorder (ADHD). Overactive behavioral approach tendencies are identified among these motivational models and are addressed within reinforcement sensitivity theory (RST). RST proposes that overactive behavioral approach is associated with over responsiveness to immediately reinforcing stimuli and results from an overactive appetitive motivational subsystem of the brain—the behavioral approach system. The current study tested the hypothesis that behavioral approach would be higher in a clinical sample of adults diagnosed with ADHD relative to a control group. Experimental and self-report measures of behavioral approach were administered. Behavioral approach was higher in the ADHD group across both methods of assessment. Effect size estimates fell within the medium to large range. Implications for how these findings might be incorporated into future ADHD models are discussed.