Charting the future of axis II

What is a psychopathology dimension?

Coherence in the science and practice of mental health assessment depends upon a tight connection between psychopathology concepts that are used and the way those concepts are operationalized and defined. In contrast, the use of the same word to mean more than one thing contributes to incoherence, inefficiency, and confusion. In this paper, we review three possible meanings of the word "dimension" as it relates to the assessment of psychopathology and describe how the indiscriminate use of this word has caused confusion in the general context of the transition to a more evidence-based approach to mental health diagnosis. We attempt to disambiguate the term "dimension" by demarcating three concepts that can be distinguished based on different empirical standards: continuous variables, unidimensional dimensions, and distinct dimensions.

The DSM's Reconnection to Psychoanalytic Theory through the Alternative Model for Personality Disorders

Often believed to have Kraepelinian origins, the Diagnostic and Statistical Manual of Mental Disorders-5th Edition (DSM-5) defines personality disorders using a categorical, hierarchical taxonomic system. This system possesses many long-standing problems for clinical practice, including a large assortment of symptom combinations that contribute to problematic heterogeneity and likely impair diagnostic validity. The DSM diagnostic system was at one time heavily influenced by psychoanalytic theory (Shorter 2005). A desire for greater theoretical neutrality then encouraged a shift away from psychoanalytic theory, resulting in the problematic atheoretical model of personality pathology introduced in DSM-III (1980) and still used today. The Alternative Model for Personality Disorders (AMPD), introduced in DSM-5 (2013), is an attempt to reconcile many of the categorical model's issues and directly parallels primary themes that characterize psychoanalytic models of personality. After a review of the historical development of DSM, three current systems for diagnosing personality pathology-the DSM-5's categorical model (2013), its AMPD (2013), and the Psychodynamic Diagnostic Manual (2nd ed.; Alliance of Psychoanalytic Organizations 2017) are compared. The comparison illustrates how the AMPD brings psychoanalytic theory back into the DSM system and acknowledges the implications of a more psychoanalytic DSM.

Borderline personality disorder and violence in the UK population: categorical and dimensional trait assessment

BACKGROUND

Borderline personality disorder (BPD) is characterised by difficulties with impulse control and affective dysregulation. It is unclear whether BPD contributes to the perpetration of violence or whether this is explained by comorbidity. We explored independent associations between categorical and dimensional representations of BPD and violence in the general population, and differential associations from individual BPD criteria.

METHODS

We used a representative combined sample of 14,753 men and women from two British national surveys of adults (≥16 years). BPD was assessed using the Structured Clinical Interview II- Questionnaire. We measured self-reported violent behaviour in the past 5 years, including severity, victims and locations of incidents. Associations for binary, dimensional and trait-level exposures were performed using weighted logistic regression, adjusted for demography and comorbid psychopathology.

RESULTS

Categorical diagnosis of BPD was associated only with intimate partner violence (IPV). Associations with serious violence leading to injuries and repetitive violence were better explained by comorbid substance misuse, anxiety and antisocial personality disorder (ASPD). However, anger and impulsivity BPD items were independently associated with most violent outcomes including severity, repetition and injury; suicidal behaviours and affective instability were not associated with violence. Both trait-level and severity-dimensional analyses showed that BPD symptoms might impact males and females differently in terms of violence.

CONCLUSIONS

For individuals diagnosed BPD, violence is better explained by comorbidity. However, BPD individual traits show different pathways to violence at the population level. Gender differences in BPD traits and their severity indicate distinct, underlying mechanisms towards violence. BPD and traits should be evaluated in perpetrators of IPV.

The Importance of Considering Clinical Utility in the Construction of a Diagnostic Manual

The development of major diagnostic manuals primarily has been guided by construct validity rather than clinical utility. The purpose of this article is to summarize recent research and theory examining the importance of clinical utility when constructing and evaluating a diagnostic manual. We suggest that construct validity is a necessary but not sufficient criterion for diagnostic constructs. This article discusses components of clinical utility and how these have applied to the current and forthcoming diagnostic manuals. Implications and suggestions for future research are provided.

A longitudinal twin study of cluster A personality disorders

BACKGROUND

While cluster A personality disorders (PDs) have been shown to be moderately heritable, we know little about the temporal stability of these genetic risk factors.

METHOD

Paranoid PD (PPD) and schizotypal PD (STPD) were assessed using the Structured Interview for DSM-IV Personality in 2793 young adult twins from the Norwegian Institute of Public Health Twin Panel at wave 1 and 2282 twins on average 10 years later at wave 2. Using the program Mx, we fitted a longitudinal latent factor model using the number of endorsed criteria for PPD and STPD.

RESULTS

The stability over time of the criteria counts for PPD and STPD, estimated as polychoric correlations, were +0.34 and +0.40, respectively. The best-fit longitudinal model included only additive genetic and individual-specific environmental factors with parameter estimates constrained to equality across the two waves. The cross-wave genetic and individual-specific environmental correlations for a latent cluster A factor were estimated to equal +1.00 and +0.13, respectively. The cross-time correlations for genetic and environmental effects specific to the individual PDs were estimated at +1.00 and +0.16-0.20, respectively. We found that 68% and 71% of the temporal stability of PPD and STPD derived, respectively, from the effect of genetic factors.

CONCLUSION

Shared genetic risk factors for two of the cluster A PDs are highly stable in adults over a 10-year period while environmental risk factors are relatively transient. Over two-thirds of the long-term stability of the common cluster A PD liability can be attributed to genetic influences.

Transitioning to a dimensional model of personality disorder in DSM 5.1 and beyond

PURPOSE OF REVIEW

To propose options for gradually transitioning to a thoroughgoing dimensional model of personality disorder.

RECENT FINDINGS

The American Psychiatric Association was less willing to implement a dimensional approach to the diagnosis of personality disorder than the leadership of the DSM-5 anticipated. The next opportunity to implement such an approach will be in the ICD-11 and the DSM 5.1.

SUMMARY

Instead of seeking a revolutionary change, attempting a more gradual transition that leads to something significantly better in the long run is likely to be more successful. For the long run, in addition to clinical utility and scientific validity, new diagnostic models must possess user acceptability. Professionals will be more likely to accept a new model if they believe it will allow them to do good work. Competent use of a dimensional model is not only a matter of increased familiarity with personality trait profiles, it requires a different kind of clinical expertise.

Personality disorders are important risk factors for disability pensioning

PURPOSE

To determine whether personality disorders (PDs) are associated with increased risk of disability pensioning in young adults, independent of other common mental disorders.

METHODS

2,770 young adults from the general population were assessed for PDs by the Structured Interview for DSM-IV Personality, and for common mental disorders by the Composite of International Diagnostic Interview. These data were linked to the Norwegian National Insurance Administration's recordings of disability benefits for a 10-year period. Logistic regression analyses were applied to investigate the association between PDs and disability pensioning. The analyses were conducted for three types of PD measures: categorical diagnoses (any PD), dimensional scores of individual PDs and higher order components retrieved by principal component analyses.

RESULTS

Having any PD was strongly associated with disability pensioning, regardless of disability diagnosis. The estimated odds ratio (OR) was substantially higher for PDs [OR 4.69 (95% confidence interval (CI) 2.6-8.5)] than for mood disorders [OR 1.3 (CI 0.7-2.3)] and anxiety disorders [OR 2.3 (CI 1.3-4.3)]. Measured dimensionally, all PD traits except antisocial traits were significantly associated with disability pensioning. After adjusting for co-occurring traits of other PDs, only schizoid, dependent and borderline PD traits showed a significant positive association with disability pension, while antisocial traits showed a significant negative association. The principal component analyses showed that negative affectivity, psychoticism, and detachment was associated with an increased risk of disability pensioning, while antagonism/disinhibition and obsessivity were not.

CONCLUSIONS

PDs are strongly associated with disability pensioning in young adults, and might be more important predictors of work disability than anxiety and depressive disorders. Certain aspects of pathologic personalities are particularly important predictors of disability.

Dimensions of personality and personality pathology: factor structure of the Shedler-Westen assessment procedure-II (SWAP-II)

Researchers have proposed replacing the current system for diagnosing personality disorders with a dimensional trait model. Proposed trait models have been derived primarily from data provided by untrained lay informants (often via self-report questionnaires) using item sets derived from lay conceptions of personality. An alternative is to derive personality trait dimensions from data provided by clinically expert informants using an instrument that includes personality features salient to clinicians who treat personality dysfunction. The authors report the factor structure of the latest edition of the Shedler-Westen Assessment Procedure (SWAP-II) using a normative clinical sample of 1,201 North American patients assessed by experienced psychologists and psychiatrists. Factor analysis identified 14 clinically and empirically coherent factors. The findings highlight dimensions of personality and personality pathology that have not emerged in personality item sets designed for lay personality description.

On the convergence between PSY-5 domains and PID-5 domains and facets: implications for assessment of DSM-5 personality traits

The DSM-5 Personality and Personality Disorders workgroup and their consultants have developed the 220-item, self-report Personality Inventory for the DSM-5 (PID-5) for direct assessment of the proposed personality trait system for DSM-5; however, most practicing clinical psychologists will likely continue to rely on separate omnibus measures to index symptoms and traits associated with psychopathology. The Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) is one such measure and assesses the Personality Psychopathology Five (PSY-5) domains, which are conceptual cognates of the DSM-5 trait domains. The current study examined the associations between the MMPI-2-RF PSY-5 scales and the DSM-5 trait domains and facets indexed by the PID-5. A clear pattern of convergence was found indicating that each of the PSY-5 scales was most highly correlated with its conceptually expected PID-5 counterpart (rs = .44-.67; Mdn r = .53) and facet correlations generally showed the same pattern. Similarly, when each of the PSY-5 scales was regressed onto the PID-5 domains, the conceptually expected pattern of associations emerged even more clearly. Finally, a joint exploratory factor analysis with the PSY-5 and PID-5 trait facet scales indicated a five-factor solution that clearly resembled both of the PSY-5/DSM-5 trait domains. These results show clear evidence that the MMPI-2-RF has utility in the assessment of dimensional personality traits proposed for the upcoming DSM-5.

The heritability of avoidant and dependent personality disorder assessed by personal interview and questionnaire

OBJECTIVE

Personality disorders (PDs) have been shown to be modestly heritable. Accurate heritability estimates are, however, dependent on reliable measurement methods, as measurement error deflates heritability. The aim of this study was to estimate the heritability of DSM-IV avoidant and dependent personality disorder, by including two measures of the PDs at two time points.

METHOD

Data were obtained from a population-based cohort of young adult Norwegian twins, of whom 8045 had completed a self-report questionnaire assessing PD traits. 2794 of these twins subsequently underwent a structured diagnostic interview for DSM-IV PDs. Questionnaire items predicting interview results were selected by multiple regression, and measurement models of the PDs were fitted in Mx.

RESULTS

The heritabilities of the PD factors were 0.64 for avoidant PD and 0.66 for dependent PD. No evidence of common environment, that is, environmental factors that are shared between twins and make them similar, was found. Genetic and environmental contributions to avoidant and dependent PD seemed to be the same across sexes.

CONCLUSION

The combination of both a questionnaire- and an interview assessment of avoidant and dependent PD results in substantially higher heritabilities than previously found using single-occasion interviews only.

[Personality and personality disorders in the elderly: diagnostic, course and management]

OBJECTIVE

Little is known about personality and personality disorders in the elderly. This paper summarizes the literature in these fields.

METHODS

Articles were selected using a Medline and Google Scholar search. The keywords were personality, personality disorder, aging and elderly.

RESULTS

Personality is not fixed and can change across the life-time including in the elderly. Personality disorders are frequent with a prevalence estimated between 10 and 20%. These rates are essentially equivalent to that of younger groups. Clinical presentation of these disorders may change over time. Longitudinal observations generally support that the "immature" personality disorders (cluster B), show improvement over time, while the more "mature" (clusters A and C) are characterized by a more chronic course. Many patients with late onset schizophrenia or delusional disorder have a premorbid cluster A personality. Patients with cluster C personality are also stable, and exposed, like all other personality disorders, to depression. Studies suggest that personality disorders may attenuate, re-emerge or appear de novo according to the cluster and the social context. Diagnosing personality disorders in the elderly is a complex undertaking, largely because of the difficulty encountered in distinguishing functional impairments related to personality from those related to physiological and environmental aspects of aging. Tools for assessing personality disorders exist, but there is no ideal assessment instrument for geriatric personality disorders. Psychiatric history and biographical elements have to be collected accurately. Personality disorders may seriously complicate mental and physical health and quality of life. Indeed, a greater risk of depression, suicide, dementia and social isolation is shown in this population. Different types of caring and treatment exist including psychotherapy and pharmacotherapy. Pharmacological strategies should consider augmentation with psychotherapeutic strategies. Interventions should target the predominant presenting problems. Indeed, personality disordered elderly people are a heterogeneous group with frequent axis I comorbidities. Care should be taken on how to administer pharmacological treatment (risk of noncompliance or abuse), pharmacokinetics, pharmacodynamics and finally interaction with age-specific comorbidities. Psychotherapy has shown its effectiveness notably in the management of depression. In institutions, clinical identification of a personality disorder would inform and advise staff regarding the approach to be adopted, and also avoid negative countertransference, emphasizing the pathological aspect of the subject's personality and his/her suffering.

CONCLUSION

Future research should develop adapted and specific diagnosis tools (dimensional and categorical mixed approach), prevention and caring in the elder population. Those studies would be able to determine the link between normal and pathological personality, mortality, depression and dementia.

Personality disorders in DSM-5

A substantive revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM) last occurred in 1994; therefore, the mental health field should anticipate significant changes to the classification of mental disorders in the fifth edition. Since DSM-5 Work Groups have recently proposed revisions for the major diagnostic classes of mental disorders, an article on the current status of the personality disorders (PDs) is timely. This article reviews scientific principles that have influenced the development of proposed changes for the assessment and diagnosis of personality psychopathology in DSM-5, presents the proposed model as of the summer of 2011, summarizes rationales for the changes, and discusses critiques of the model. Scientific principles were articulated for DSM-5 more than a decade ago; their application to the process has not been straightforward, however. Work Group members have labored to improve the DSM-5 approach to personality and PDs to make the classification more valid and more clinically useful. The current model continues to be a work in progress.

Distinguishing general and specific personality disorder features and implications for substance dependence comorbidity

Clinical and population-based samples show high comorbidity between Substance Use Disorders (SUDs) and Axis II Personality Disorders (PDs). However, Axis II disorders are frequently comorbid with each other, and existing research has generally failed to distinguish the extent to which SUD/PD comorbidity is general or specific with respect to both specific types of PDs and specific types of SUDs. We sought to determine whether ostensibly specific comorbid substance dependence-Axis II diagnoses (e.g., alcohol use dependence and borderline personality disorder) are reflective of more pervasive or general personality pathology or whether the comorbidity is specific to individual PDs. Face-to-face interview data from Wave 1 and Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions were analyzed. Participants included 34,653 adults living in households in the United States. We used hierarchical factor models to statistically partition general and specific personality disorder dimensions while simultaneously testing for specific PD-substance dependence relations. Results indicated that substance dependence-Axis II comorbidity is characterized by general (pervasive) pathology and by Cluster B PD pathology over and above the relationship to the general PD factor. Further, these relations between PD factors and substance dependence diagnoses appeared to largely account for the comorbidity among substance dependence diagnoses in the younger but not older participants. Our findings suggest that a failure to consider the general PD factor, which we interpret as reflecting interpersonal dysfunction, can lead to potential mischaracterizations of the nature of certain PD and SUD comorbidities.

Computerized adaptive assessment of personality disorder: introducing the CAT-PD project

Assessment of personality disorders (PD) has been hindered by reliance on the problematic categorical model embodied in the most recent Diagnostic and Statistical Model of Mental Disorders (DSM), lack of consensus among alternative dimensional models, and inefficient measurement methods. This article describes the rationale for and early results from a multiyear study funded by the National Institute of Mental Health that was designed to develop an integrative and comprehensive model and efficient measure of PD trait dimensions. To accomplish these goals, we are in the midst of a 5-phase project to develop and validate the model and measure. The results of Phase 1 of the project--which was focused on developing the PD traits to be assessed and the initial item pool--resulted in a candidate list of 59 PD traits and an initial item pool of 2,589 items. Data collection and structural analyses in community and patient samples will inform the ultimate structure of the measure, and computerized adaptive testing will permit efficient measurement of the resultant traits. The resultant Computerized Adaptive Test of Personality Disorder (CAT-PD) will be well positioned as a measure of the proposed DSM-5 PD traits. Implications for both applied and basic personality research are discussed.

Personality disorder diagnostic thresholds correspond to different levels of latent pathology

To meet a diagnosis for a particular personality disorder (PD), among other requirements, a person must exhibit a specified minimum number of the features outlined for that PD, otherwise referred to as the diagnostic threshold. Despite many years of research on the DSM PDs, there is little empirical basis for the chosen thresholds. The present study used mechanisms of item response theory (IRT) to link the diagnostic thresholds of six PDs to their corresponding level of latent PD pathology. Consistent with our hypothesis, analyses of the data from 41,227 participants revealed that PD diagnostic thresholds corresponded to a wide range of latent pathology. For example, the diagnostic threshold for schizoid PD corresponded to 1.54 SDs of pathology whereas the threshold for dependent PD corresponded to 2.72 SDs of pathology. The current analyses have demonstrated for the first time that the latent pathology associated with each PD threshold varies widely, and thus has quantified what others accurately have speculated. Implications and considerations for the future directions of PD classification are discussed.

The structure of genetic and environmental risk factors for syndromal and subsyndromal common DSM-IV axis I and all axis II disorders

OBJECTIVE

The authors sought to clarify the structure of the genetic and environmental risk factors for 22 DSM-IV disorders: 12 common axis I disorders and all 10 axis II disorders.

METHOD

The authors examined syndromal and subsyndromal axis I diagnoses and five categories reflecting number of endorsed criteria for axis II disorders in 2,111 personally interviewed young adult members of the Norwegian Institute of Public Health Twin Panel.

RESULTS

Four correlated genetic factors were identified: axis I internalizing, axis II internalizing, axis I externalizing, and axis II externalizing. Factors 1 and 2 and factors 3 and 4 were moderately correlated, supporting the importance of the internalizing-externalizing distinction. Five disorders had substantial loadings on two factors: borderline personality disorder (factors 3 and 4), somatoform disorder (factors 1 and 2), paranoid and dependent personality disorders (factors 2 and 4), and eating disorders (factors 1 and 4). Three correlated environmental factors were identified: axis II disorders, axis I internalizing disorders, and externalizing disorders versus anxiety disorders.

CONCLUSIONS

Common axis I and II psychiatric disorders have a coherent underlying genetic structure that reflects two major dimensions: internalizing versus externalizing, and axis I versus axis II. The underlying structure of environmental influences is quite different. The organization of common psychiatric disorders into coherent groups results largely from genetic, not environmental, factors. These results should be interpreted in the context of unavoidable limitations of current statistical methods applied to this number of diagnostic categories.

The genetic epidemiology of personality disorders

Genetic epidemiologic studies indicate that all ten personality disorders (PDs) classified on the DSM-IV axis II are modestly to moderately heritable. Shared environmental and nonadditive genetic factors are of minor or no importance. No sex differences have been identified. Multivariate studies suggest that the extensive comorbidity between the PDs can be explained by three common genetic and environmental risk factors. The genetic factors do not reflect the DSM-IV cluster structure, but rather: i) broad vulnerability to PD pathology or negative emotionality; ii) high impulsivity/low agreeableness; and iii) introversion. Common genetic and environmental liability factors contribute to comorbidity between pairs or clusters of axis I and axis II disorders. Molecular genetic studies of PDs, mostly candidate gene association studies, indicate that genes linked to neurotransmitter pathways, especially in the serotonergic and dopaminergic systems, are involved. Future studies, using newer methods like genome-wide association, might take advantage of the use of endophenotypes.

Five-year prospective study of personality disorders in adults with longstanding eating disorders

OBJECTIVE

To (1) report the occurrence of personality disorders (PDs) in adults with eating disorders (EDs) during inpatient treatment, and at 1-, 2-, and 5-year follow-up, (2) compare the changes of PDs in anorexia nervosa (AN), bulimia nervosa (BN), and eating disorder not otherwise specified (EDNOS), and (3) investigate if recovered patients had lower frequency of PDs.

METHOD

Seventy-four patients with EDs were assessed with Structured Clinical Interview for DSM-IV Axis II disorders during inpatient treatment, and at 1-, 2-, and 5-year follow-up.

RESULTS

During inpatient treatment, 58 patients (78%) had one or more PDs and this was reduced to 32 (43%) at 5-year follow-up. Dimensional PD scores changed significantly over time in both AN, BN, and EDNOS, but no significant differences emerged among the ED groups. Recovered patients had lower frequency of PDs (p < 0.01).

DISCUSSION

The substantial 5-year follow-up reductions in the frequency of PDs in patients with EDs present an optimistic clinical scenario for treating patients with comorbid ED and PD.

Depressive Personality Disorder: A Comparison of Three Self-Report Measures

Depressive personality disorder (DPD) was included in the appendix of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition ( DSM-IV) for further study. Questions abound regarding this disorder in terms of its distinctiveness from extant diagnostic constructs and clinical significance.This study examines the interrelations between three assessments of DPD and their relations to pathological personality traits and disorders in a sample of undergraduates ( N = 182). The DPD indices evinced adequate convergence with each other (mean r = .60) and similar pathological personality profiles. The authors also tested the incremental validity of the DPD scores in relation to psychological functioning, after controlling for depressive symptoms and the DSM-IV personality disorders (PDs). The DPD scores manifested limited incremental validity, mainly in the form of predicting lower levels of positive affectivity. Our results suggest that this is not specific to DPD, however, as the official PDs also manifested limited incremental validity.

Five-factor model of personality disorder: a proposal for DSM-V

The predominant dimensional model of general personality structure within psychology is the five-factor model (FFM). Research indicates that the personality disorders of the American Psychiatric Association's diagnostic manual can be understood as maladaptive variants of the domains and facets of the FFM. The current review provides a proposal for the classification of personality disorder from the perspective of the FFM. Discussed as well are implications and issues associated with an FFM of personality disorder, including the integration of a psychiatric nomenclature with general personality structure, the inclusion of a domain of openness to experience, the identification of problems in living associated with maladaptive personality traits, the setting of a diagnostic threshold, prototypal matching, feasibility, and clinical utility.

Evolução do DSM quanto ao critério categorial de diagnóstico para o distúrbio da personalidade antissocial

OBJETIVO: Realizar um breve percurso sobre o desenvolvimento conceitual de um dos construtos psicológicos de maior evidência nos dias atuais, a saber: o transtorno de personalidade antissocial (TPAS). Especificamente, esse percurso se realiza no sistema categórico proposto pela Associação Americana de Psiquiatria (APA), o Manual Diagnóstico e Estatístico de Distúrbios Mentais (DSM). MÉTODO: Utilizou-se a revisão literária sobre a evolução e a avaliação do construto associada a pesquisas empíricas consultadas nos principais livros e periódicos de reconhecimento internacional na área, tais como: Personality and Individual Differences, Psychological Medicine, Annual Review of Clinical Psychology, Psychological Bulletin, Journal of Abnormal Psychology, Journal of Personality Assessment, International Journal of Offender Therapy and Comparative Criminology, Aggression and Violent Behavior, Handbook of Psychopathy, entre outros. RESULTADO: Observa-se que o diagnóstico do TPAS é baseado nos critérios categóricos e não dimensionais. Isso significa que o sistema não consegue predizer a priori a variabilidade (intensidade) dos traços desse transtorno por ser o DSM desenvolvido no reconhecimento de sintomas e síndromes. CONCLUSÃO: Apesar de o TPAS ter passado por diversas revisões e de apresentar insuficiência taxonômica, ele ainda é amplamente utilizado no diagnóstico e no prognóstico clínico de condições relacionadas ao comportamento social desviante.

The co-morbidity of personality disorder and clinical syndromes in prisoners

OBJECTIVES

Our aim was to examine patterns of Axis II co-morbidity using data from the national survey of psychiatric morbidity among prisoners in England and Wales.

METHODS

A one-in-five sub-sample of participants in a survey of psychiatric morbidity among prisoners in England and Wales was interviewed using the Schedule for Clinical Assessment in Neuropsychiatry and the Structured Clinical Interview for the fourth edition of the Diagnostic and Statistical Manual of Mental Health Disorders Axis II personality disorders (PD). Logistic regression analysis was conducted adjusting for confounders of associations with co-morbid psychopathology disorders, age and gender.

RESULTS

The most prevalent Axis II disorders in the sample were anti-social, paranoid and borderline PD. Following logistic regression, anti-social and borderline PD demonstrated high levels of co-morbidity with both Axis I and other Axis II disorders, narcissistic PD with other Axis II, and paranoid and avoidant PD with Axis I disorders.

CONCLUSIONS

Certain Axis II disorders may increase the risk for lifetime Axis I disorders. Although appropriate statistical procedures reduce the level of Axis II co-morbidity, some patterns may be artefacts of a diagnostic system encouraging multiple diagnostic categories.

The structure of genetic and environmental risk factors for DSM-IV personality disorders: a multivariate twin study

CONTEXT

Although both genetic and environmental factors affect risk of individual personality disorders (PDs), we know little of how they contribute to the pattern of comorbidity between the PDs in the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV).

OBJECTIVE

To clarify the structure of the genetic and environmental risk factors for the 10 DSM-IV PDs.

DESIGN

Assessment of PDs at personal interview and multivariate twin modeling with the Mx program.

SETTING

General community.

PARTICIPANTS

A total of 2794 young adult members of the Norwegian Institute of Public Health Twin Panel. Main Outcome Measure Number of endorsed criteria for the 10 DSM-IV PDs.

RESULTS

The best-fit multivariate twin model required 3 genetic and 3 individual-specific environmental factors and genetic and individual-specific factors unique to each PD. The first genetic factor had high loadings on PDs from all 3 clusters including paranoid, histrionic, borderline, narcissistic, dependent, and obsessive-compulsive. The second genetic factor had substantial loadings only on borderline and antisocial PD. The third genetic factor had high loadings only on schizoid and avoidant PD. Several PDs had substantial disorder-specific genetic risk factors. The first, second, and third individual-specific environmental factors had high loadings on the cluster B, A, and C PDs, respectively, with 1 exception: obsessive-compulsive PD loaded with cluster B and not cluster C PDs.

CONCLUSIONS

Genetic risk factors for DSM-IV PDs do not reflect the cluster A, B, and C typology. Rather, 1 genetic factor reflects a broad vulnerability to PD pathology and/or negative emotionality. The 2 other genetic factors are more specific and reflect high impulsivity/low agreeableness and introversion. Unexpectedly, the cluster A, B, and C typology is well reflected in the structure of environmental risk factors, suggesting that environmental experiences may be responsible for the tendency of cluster A, B, and C PDs to co-occur.

A dimensional model of personality disorder: proposal for DSM-V

A proposal made for DSM-IV was to include a means with which to provide a dimensional profile of a patient in terms of the diagnostic categories. However, a suggestion of the DSM-V Research Planning Conference on personality disorders was to develop a more fundamental revision through an integration of alternative dimensional models of personality disorder and general personality structure. A purpose of the current article is to provide this proposal. Also discussed is a primary concern with respect to the implementation of any such dimensional model: clinical utility. Discussed in particular are concerns regarding feasibility and treatment implications.

Genetics of personality disorders

This review of the literature on genetic contributions to the etiology of personality disorders broadly follows the DSM classification, and begins by evaluating the current evidence for genetic influences on the DSM axis II disorders. One of the most exciting directions in psychiatric genetics is the rapidly developing field of molecular genetic studies aiming to identify specific genes correlated with psychiatric phenotypes. Personality disorders, like most other psychiatric diagnostic categories, are etiologically complex, which implies that they are influenced by several genes and several environmental factors. The interplay between genes and the environment is a field that is receiving increasing attention and is addressed both in relation to quantitative and molecular methods.

Clinical utility of five dimensional systems for personality diagnosis: a "consumer preference" study

This study compares the clinical relevance and utility of five dimensional diagnostic systems for personality disorders that have been proposed for the forthcoming edition of DSM (DSM-V): (1) a criteria counting model based on current DSM-IV diagnostic criteria; (2) a prototype matching model based on current DSM-IV diagnostic criteria; (3) a prototype matching model based on the Shedler-Westen Assessment Procedure (SWAP); (4) the Five Factor Model; and (5) Cloninger's Psychobiological Model. A random national sample of psychiatrists and psychologists applied all 5 diagnostic systems to a patient in their care and rated the clinical utility of each system. The SWAP Prototype Matching and DSM-IV Prototype Matching models were judged most clinically useful and relevant. The Five Factor Model and Cloninger's Psychobiological Model were judged least useful. The prototype matching systems most faithfully capture the personality syndromes seen in clinical practice, and permit rich descriptions of diagnostic constructs without a proportionate increase in user effort. A prototype matching approach to personality diagnosis deserves consideration for DSM-V.

Dimensional models of personality disorder: Diagnostic and Statistical Manual of Mental Disorders Fifth Edition and beyond

PURPOSE OF REVIEW

We describe several dimensional models of personality disorders and highlight future directions for the integration of dimensional approaches in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V). This review is timely and relevant, given the upcoming revision of DSM (DSM-V).

RECENT FINDINGS

Research has identified four common higher order factors that could be used to characterize personality pathology. Evidence supports the inclusion of this dimensional representation of personality disorders in DSM-V, possibly as an adjunct to the traditional categorical classification scheme. A dimensional approach would ameliorate many of the problems associated with the categorical approach. Issues that still need to be addressed are on how to integrate these dimensions into the current classification system in a way that they will be accepted by clinicians and psychopathologists. The clinical utility of the dimensional models must be demonstrated, and the development of a method that combines trait elevations and impairment associated with personality pathology is needed in order to define personality disorder from a dimensional perspective.

SUMMARY

Although there may be some initial resistance to the incorporation of the dimensional models in the future diagnostic manuals, researchers and clinicians are expected to benefit from the more reliable and valid portrayal of personality pathology.

Synthesizing dimensional and categorical approaches to personality disorders: refining the research agenda for DSM-V Axis II

Personality disorder researchers have long considered the utility of dimensional approaches to diagnosis, signaling the need to consider a dimensional approach for personality disorders in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V). Nevertheless, a dimensional approach to personality disorders in DSM-V is more likely to succeed if it represents an orderly and logical progression from the categorical system in DSM-IV. With these considerations and opportunities in mind, the authors sought to delineate ways of synthesizing categorical and dimensional approaches to personality disorders that could inform the construction of DSM-V. This discussion resulted in (1) the idea of having a set of core descriptive elements of personality for DSM-V, (2) an approach to rating those elements for specific patients, (3) a way of combining those elements into personality disorder prototypes, and (4) a revised conception of personality disorder as a construct separate from personality traits.

Clinical utility: a prerequisite for the adoption of a dimensional approach in DSM

A potential obstacle to implementing dimensional representations in the Diagnostic and Statistical Manual of Mental Disorders (DSM) is lack of data about clinical utility and user acceptability. Adopting a dimensional approach would likely complicate medical record keeping, create administrative and clinical barriers between mental disorders and medical conditions, require a massive retreating effort, disrupt research efforts (e.g., meta-analyses), and complicate clinicians' efforts to integrate prior clinical research using DSM categories into clinical practice. Efforts to empirically demonstrate the clinical utility of dimensional alternatives should be a prerequisite for their future implementation in order to establish that their advantages outweigh the disadvantages. Approaches to promote user acceptability and the development of an empirical database include dimensionalizing existing DSM categories and including research dimensions in the DSM appendix.

A structure-based expert model of the ICD-10 mental disorders

BACKGROUND

Many authors have highlighted that a classificatory system such as the ICD-10 or the DSM-IV should attempt to integrate categorical as well as dimensional aspects rather than relying only on a categorical distinction.

METHODS

In the current study, a method is presented that allows both perspectives to be considered. Based on their clinical experience, 20 therapists were asked to rate a selection of ICD-10 mental disorders in terms of their similarity. The resulting data were processed by nonmetric multidimensional scaling on individual basis as well as mean basis and a cluster analysis.

RESULTS

From a categorical point of view, the resulting mean cognitive map and the cluster analytic groups showed a good concordance with the ICD-10 F groups. Additionally, analogies to the critical observations with regard to the classification systems could be observed. From the dimensional point of view, there were two dimensions found (cognition and psychosis) which showed high correlations in the mean map.

CONCLUSIONS

The method presented in this study offers an opportunity to account for dimensional as well as categorical aspects of classification by exploring the structure of the ICD-10 mental disorders directly from the point of view of therapists and thus creating the basis for an expert model.

The Collaborative Longitudinal Personality Disorders Study (CLPS): overview and implications

The Collaborative Longitudinal Personality Disorders Study (CLPS; Gunderson et al., 2000) was developed to fill gaps in our understanding of the nature, course, and impact of personality disorders (PDs). Here, we review published findings to date, discuss their implications for current conceptualizations of PDs, and raise questions that warrant future consideration. We have found that PDs are more stable than major depressive disorder, but that meaningful improvements are possible and not uncommon. We have confirmed also that PDs constitute a significant public health problem, with respect to associated functional impairment, extensive treatment utilization, negative prognostic impact on major depressive disorder, and suicide risk. At the same time, we have demonstrated that dimensional models of PDs have clinical validity that categories do not, especially greater temporal stability. Furthermore, dimensional personality traits appear to be the foundation of behaviors described by many PD criteria. Taken together, our results lead us to hypothesize that PDs may be reconceptualized as hybrids of stable personality traits and intermittently expressed symptomatic behaviors.

The problem of severity in the classification of personality disorder

The articles in this series are very valuable but have one omission that is very important in clinical practice; they do not address the question of severity. In this article I argue that the measure of severity, using what are described as hybrid models, is a critical component of practice and can be recorded easily using standard systems, both existing and planned. In arguing this case I will use an exemplar, the Personality Assessment Schedule (PAS), mainly because we have so much data from this instrument, but emphasize that other assessment procedures can be easily adapted to produce similar severity assessments.

Clinical utility of dimensional models for personality pathology

Clinical utility is defined as the extent to which the DSM assists clinical decision makers in fulfilling the various clinical functions of a psychiatric classification system. Distinction is made between elements of diagnostic validity that are more or less conditional to utility (i.e., coverage, and consistency with etiology and prognosis) and components of clinical utility in the narrow sense of the term (i.e., user acceptability and accuracy, communication, reliability, subtlety, and clinical decision making). Clinical utility is often considered the driving force behind the respective revisions of the DSM system, yet it has been difficult if not impossible to obtain reasonable levels of clinical utility within categorical classifications of personality disorders. This paper presents evidence that a dimensional diagnostic system will substantially improve clinical utility, especially with respect to coverage, reliability, subtlety, and clinical decision making. In addition, some evidence suggests that the purely dimensional models outperform the so-called hybrid models (i.e., dimensional profiling of categories) with respect to coverage, consistency with etiology, subtlety, and clinical decision making. Several research options that might inform future revisions, including the choice or development of a dimensional classification, are suggested.

Categorical and Dimensional Models of Personality Disorder

We review major categorical and dimensional models of personality pathology, highlighting advantages and disadvantages of these approaches. Several analytic and methodological approaches to the question of the categorical versus dimensional status of constructs are discussed, including taxometric analyses, latent class analyses, and multivariate genetic analyses. Based on our review, we advocate a dimensional approach to classifying personality pathology. There is converging evidence that four major domains of personality are relevant to personality pathology: neuroticism/negative affectivity/emotional dysregulation; extraversion/positive emotionality; dissocial/antagonistic behavior; and constraint/compulsivity/conscientiousness. Finally, we discuss how dimensional approaches might be integrated into the diagnostic system, as well as some of the major issues that must be addressed in order for dimensional approaches to gain wide acceptance.

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.

Difficulties in the assessment of personality traits and disorders in eating-disordered individuals

There are compelling reasons to examine personality variables in the eating disorder (ED) field but many impediments to the collection of useful data. In addition to the conceptual and methodological difficulties associated with personality assessment in the general case, the EDs present a number of special problems. These include patients' young age at onset and evaluation, the "state" effects of semi-starvation and chaotic eating, denial and distortion in self-report, the instability of ED subtypes, and the intrusion of eating and weight concerns into a wide range of apparently unrelated domains. Although there is substantial support for the clinical view that personality variables are linked to anorexia nervosa (AN) and bulimia nervosa (BN), the identification of stable traits and Axis II disorders in individual patients should be deferred until after the initial phase of treatment.

Two-year stability and change of schizotypal, borderline, avoidant, and obsessive-compulsive personality disorders

The authors examined the stability of schizotypal (STPD), borderline (BPD), avoidant (AVPD) and obsessive-compulsive (OCPD) personality disorders (PDs) over 2 years of prospective multiwave follow-up. Six hundred thirty-three participants recruited at 4 collaborating sites who met criteria for 1 or more of the 4 PDs or for major depressive disorder (MOD) without PD were assessed with semistructured interviews at baseline, 6, 12, and 24 months. Lifetable survival analyses revealed that the PD groups had slower time to remission than the MDD group. Categorically, PD remission rates range from 50% (AVPD) to 61% (STPD) for dropping below diagnostic threshold on a blind 24-month reassessment but range from 23% (STPD) to 38% (OCPD) for a more stringent definition of improvement. Dimensionally, these findings suggest that PDs may be characterized by maladaptive trait constellations that are stable in their structure (individual differences) but can change in severity or expression over time.