W. John Livesley

The borderline diagnosis I: psychopathology, comorbidity, and personaltity structure

Borderline personality disorder (BPD) is a complex and serious mental disorder associated with severe functional impairment, substantial treatment utilization, and a high rate of mortality by suicide. Recently, BPD has become a focus of intensifying study. In Part I of this three-part article meant to provide a foundation to researchers on the current status of the borderline diagnosis and prospects for its future development, we examine the psychopathology, comorbidity, and personality structure of BPD. Although the descriptive characteristics of BPD are well-represented by DSM-IV diagnostic criteria, other important aspects of BPD psychopathology are not included. The descriptive criteria in conjunction with semistructured interviews have, however, increased the ability of investigators to diagnose BPD as reliably as many Axis I disorders. Frequent comorbidity of BPD with Axis I disorders necessitates a broad assessment of psychopathology to help account for clinical heterogeneity. Because of the absence of evidence of the validity of the diagnostic threshold for a categorical diagnosis of BPD, and because of the heterogeneity within the diagnosis, investigators should also supplement their DSM-IV diagnoses with assessments of underlying personality trait structures. Although there are a number of competing models of personality structure, they have remarkable convergence on a set of three to five basic personality dimensions.

The borderline diagnosis II: biology, genetics, and clinical course

In Part I of this three-part article, consideration of the core features of BPD psychopathology, of comorbidity with Axis I disorders, and of underlying personality trait structure suggested that the borderline diagnosis might be productively studied from the perspective of dimensions of trait expression, in addition to that of the category itself. In Part II, we review the biology, genetics, and clinical course of borderline personality disorder (BPD), continuing to attend to the utility of a focus on fundamental dimensions of psychopathology. Biological approaches to the study of personality can identify individual differences with both genetic and environmental influences. The aspects of personality disorder that are likely to have biologic correlates are those involving regulation of affects, impulse/action patterns, cognitive organization and anxiety/inhibition. For BPD, key psychobiological domains include impulsive aggression, associated with reduced serotonergic activity in the brain, and affective instability, associated with increased responsivity of cholinergic systems. There may be a strong genetic component for the development of BPD, but it seems clear, at least, that there are strong genetic influences on traits that underlie it, such as neuroticism, impulsivity, anxiousness, affective lability, and insecure attachment. The course of BPD suggests a heterogeneous disorder. Predictors of poor prognosis include history of childhood sexual abuse, early age at first psychiatric contact, chronicity of symptoms, affective instability, aggression, substance abuse, and increased comorbidity. For research purposes, at least, biological, genetic, and prognostic studies all continue to suggest the need to supplement categorical diagnoses of BPD with assessments of key underlying personality trait dimensions and with historical and clinical observations apart from those needed to make the borderline diagnosis itself.

Factorial structure of traits delineating personality disorders in clinical and general population samples.

Categorical and dimensional models for classifying personality disorders were evaluated by comparing the structure of personality pathology in a clinical sample (n = 158) with the structure in a general population sample (n = 274). Subjects completed 100 personality scales. Separate factor analyses revealed similar structures in the 2 samples. An underlying structure in a combined sample showed limited agreement with the concepts of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1987). Fifteen factors were retained: Generalized Distress, Rejection, Restricted Expression, Compulsivity, Stimulus Seeking, Insecure Attachment, Diffidence, Intimacy Problems, Oppositionality, Interpersonal Disesteem, Conduct Problems, Cognitive Dysfunction, Affective Reactivity, Narcissism, and Social Apprehensiveness. The results are consistent with a dimensional representation of personality disorder.

Is the genetic structure of human personality universal? A cross-cultural twin study from North America, Europe, and Asia.

This study examined whether universality of the 5-factor model (FFM) of personality operationalized by the Revised NEO Personality Inventory is due to genetic influences that are invariant across diverse nations. Factor analyses were conducted on matrices of phenotypic, genetic, and environmental correlations estimated in a sample of 1,209 monozygotic and 701 dizygotic twin pairs from Canada, Germany, and Japan. Five genetic and environmental factors were extracted for each sample. High congruence coefficients were observed when phenotypic, genetic, and environmental factors were compared in each sample as well as when each factor was compared across samples. These results suggest that the FFM has a solid biological basis and may represent a common heritage of the human species.

Deriving an empirical structure of personality pathology for DSM-5.

The DSM-IV model of personality disorders is composed of trait sets arranged into 10 theoretically distinct, polythetically assessed categories, with little regard for how the traits comprising these disorders are interrelated and structured. Research since the publication of DSM-III has shown that this model is untenable. The question is not whether this model needs revision; rather, the question is how to move from the existing DSM-IV framework to a model better connected with data. Empirically-based models of personality trait variation provide a starting point for DSM-5, and ongoing research will be used to delineate further the empirical structure of personality traits in the pathological range. The ultimate goal is to frame future DSMs in a way that is maximally useful for clinicians as well as researchers. It is also critical to understand that the DSM-5 is intended to be a living document that will facilitate novel inquiry and clinical applications, as opposed to a document designed to promote and perpetuate a fixed set of constructs. Thus, we view a proposed trait system as a first step on a path to a well-validated, clinically-useful structure.

Dimensions of Personality Disorder and Their Relationships to the Big Five Dimensions of Personality.

Researchers have suggested that personality disorders (PDs) could be better understood with a dimensional model than with the DSM-IIII-R categorical system. The authors conceptualized PDs as extreme expressions of personality functioning. Dimensional measures of aspects of PD were developed for the present study on the basis of previous factor-analytic investigations. The authors examined the convergence of these measures with Costa and McCraes «Big Five» factors in a sample of 300 general-population subjects

The borderline diagnosis III: identifying endophenotypes for genetic studies.

Although it is generally acknowledged that borderline personality disorder (BPD) has a complex, multifactorial etiology with interacting genetic and environmental substrates, the specific genetic underpinnings of this disorder have not been extensively investigated. Family aggregation studies suggest the heritability for BPD as a diagnosis, but the genetic basis for this disorder may be stronger for dimensions such as impulsivity/aggression and affective instability than for the diagnostic criteria itself. Family, adoptive, and twin studies also converge to support an underlying genetic component to the disorder. An endophenotypic approach to defining the genetics of this complex disorder may be called for. Twin studies in an epidemiologic, non-clinically ascertained sample using both diagnostic measures and laboratory measures that can be operationalized, including neuropsychologic, psychophysiologic, and operationalized behavioral tests, may be useful. Large-scale family studies of clinically ascertained samples with careful diagnostic demarcation and measurement of endophenotypes in probands and relatives may also prove to be a promising approach. The use of laboratory paradigms for measures of aggression and affective instability are discussed in the context of such endophenotypic approaches.

Genetic and environmental influences on the covariance of facets defining the domains of the five-factor model of personality

Multivariate genetic analyses were applied to the six facets defining each of the five personality domains (Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness) assessed by Costa and McCraes Revised NEO Personality Inventory (NEO-PI-R). The analyses are designed to partition the observed covariance of facets defining each domain into their genetic and environmental bases to determine the basis for their coherence as a domain. The analyses were applied separately to a sample of 253 identical and 207 fraternal twin pairs from Canada and 526 identical and 269 fraternal pairs from Germany. Results showed that each of the NEO-PI-R domains is composed of multiple genetic and environmental factors common to the facets supporting the observed coherence of the NEO-PI-R facet sets. Differences between the German and Canadian sample appeared limited to the magnitude of the genetic and environmental effects on each facet, but not the number or type of genetic and environmental influences.

Sources of structure: Genetic, environmental, and artifactual influences on the covariation of personality traits

The phenotypic structure of personality traits has been well described, but it has not yet been explained causally. Behavior genetic covariance analyses can identify the underlying causes of phenotypic structure; previous behavior genetic research has suggested that the effects from both genetic and nonshared environmental influences mirror the phenotype. However, nonshared environmental effects are usually estimated as a residualterm that may also include systematic bias, such as that introduced by implicit personality theory. To reduce that bias, we supplemented data from Canadian and German twin studies with cross-observer correlations on the Revised NEO Personality Inventory. The hypothesized five-factor structure was found in both the phenotypic and genetic/familial covariances. When the residual covariance was decomposed into true nonshared environmental influences and method bias, only the latter showed the five-factor structure. True nonshared environmental influences are not structured as genetic influences are, although there was some suggestion that they do affect two personality dimensions, Conscientiousness and Love. These data reaffirm the value of behavior genetic analyses for research on the underlying causes of personality traits.

Heritability of social anxiety-related concerns and personality characteristics: a twin study.

Negative evaluation fears figure prominently in the cognitive psychology of patients with social phobia. In this study, we examine the heritability of negative evaluation fears by using a twin sample. The authors also examine the relationships between negative evaluation fears and personality dimensions relevant to social phobia. Scores on the brief version of the Fear of Negative Evaluation Scale (BFNE) were examined in a sample of 437 (245 monozygotic and 192 dizygotic) twin pairs. Biometrical model fitting was conducted by using standard statistical methods. Genetic and environmental correlations with personality dimensions (from the Dimensional Assessment of Personality Pathology-Basic Questionnaire) were also calculated. Broad heritability estimate of the BFNE was 48%. Additive genetic effects and unique environmental effects emerged as the primary influences on negative evaluation fears. Genetic correlations between BFNE scores and the submissiveness, anxiousness, and social avoidance facets of the Dimensional Assessment of Personality Pathology-Basic Questionnaire were high (rg = .78 to .80). A cognitive dimension central to the phenomenology (and, perhaps, cause) of social phobia, the fear of being negatively evaluated, is moderately heritable. Moreover, the same genes that influence negative evaluation fears appear to influence a cluster of anxiety-related personality characteristics. Implications and limitations of these findings are discussed.