Accurate phenotyping: Reconciling approaches through Bayesian model averaging.

Genetic research into complex diseases is frequently hindered by a lack of clear biomarkers for phenotype ascertainment. Phenotypes for such diseases are often identified on the basis of clinically defined criteria; however such criteria may not be suitable for understanding the genetic composition of the diseases. Various statistical approaches have been proposed for phenotype definition; however our previous studies have shown that differences in phenotypes estimated using different approaches have substantial impact on subsequent analyses. Instead of obtaining results based upon a single model, we propose a new method, using Bayesian model averaging to overcome problems associated with phenotype definition. Although Bayesian model averaging has been used in other fields of research, this is the first study that uses Bayesian model averaging to reconcile phenotypes obtained using multiple models. We illustrate the new method by applying it to simulated genetic and phenotypic data for Kofendred personality disorder-an imaginary disease with several sub-types. Two separate statistical methods were used to identify clusters of individuals with distinct phenotypes: latent class analysis and grade of membership. Bayesian model averaging was then used to combine the two clusterings for the purpose of subsequent linkage analyses. We found that causative genetic loci for the disease produced higher LOD scores using model averaging than under either individual model separately. We attribute this improvement to consolidation of the cores of phenotype clusters identified using each individual method.

A comparison of passive-aggressive and negativistic personality disorders.

Passive-aggressive personality disorder (PAPD) has historically played an important role in clinical theorizing and was diagnosable prior to the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994), in which the construct was relabeled negativistic (NEGPD), expanded to include negative affective symptoms, and appendicized. In this study we tested the hypothesis that the expansion of PAPD to include content related to negative moods and nonspecific personality pathology compromised its discriminant validity. In an undergraduate sample (N = 1,215), a self-report measure of PAPD was only moderately related to NEGPD and showed less diagnostic overlap with other personality disorders than NEGPD. Furthermore, a conjoint factor analysis yielded a strong first factor (moodiness) that appeared less specific to passive-aggressive behavior than 3 other factors (irresponsibility, inadequacy, and contempt). We conclude that future research on this potentially important clinical construct should focus on core passive-aggressive features and abandon the negativistic content that has been added to it in successive editions of the DSM.

Do aggression and rule-breaking have different interpersonal correlates? A study of antisocial behavior subtypes, negative affect, and hostile perceptions of others.

There is mounting evidence that physical aggression and nonaggressive, rule-breaking delinquency constitute two separable though correlated subtypes of antisocial behavior. Even so, it remains unclear whether these behavioral subtypes have meaningfully different interpersonal correlates, particularly as they are subsumed within the same broad domain of antisocial behavior. To evaluate this, we examined whether hostile perceptions of others (assessed via exposure to a series of neutral unknown faces) were linked to level and type of antisocial behavior aggression vs. rule-breaking, and moreover, whether this association persisted even when also considering the common association with negative affect (as manipulated via written recollection of one's best and worst life experiences). Analyses revealed that aggression, but not rule-breaking, was uniquely tied to hostile perceptions of others. Furthermore, this association persisted over and above the common association of both hostile perceptions and aggression with negative affect (at both trait and state levels). Such results provide additional support for clinically meaningful differences between the behavioral subtypes of aggression and nonaggressive rule-breaking and for the independent role of hostile perceptions in aggressive behavior.

Passive-aggressive (negativistic) personality disorder: a population-based twin study.

The objective of this study was to investigate the familial aggregation of passive aggressive personality disorder (PAPD), and explore issues regarding PAPD raised by the DSM-IV Personality Disorder Work Group. Two thousand seven hundred and ninety-four Norwegian twins from the population-based Norwegian Institute of Public Health Twin Panel were interviewed with the Structured Interview for DSM-IV Personality (SIDP-IV). Because of the rarity of the twins meeting full diagnostic criteria for PAPD a dimensional representation of the disorder was used for the analyses. Overlap with other axis II disorders was assessed by polychoric correlations, while familial aggregation was explored by structural equation twin models. Overlap was highest with paranoid (r = 0.52) and borderline personality disorder (r = 0.53), and lowest with schizoid (r = 0.26). Significant familial aggregation was found for PAPD. The twin correlations and parameter estimates in the full model indicated genetic and shared environmental effects for females, and only shared environmental effects for males, but the prevalence of endorsed PAPD criteria in this community sample was too low to permit us to conclude with confidence regarding the relative influence of genetic and shared environmental factors on the familial aggregation of PAPD.

The validity of DSM-IV passive-aggressive (negativistic) personality disorder.

Passive-Aggressive (Negativistic) Personality Disorder (NEGPD), listed in Appendix B of the DSM-IV, is not an officially recognized personality disorder. Its future as a discrete disorder is uncertain (Widiger, 2003). Yet, NEGPD occupies a role in some theoretical formulations of personality pathology (Millon & Davis, 1996), and many clinicians believe that passive-aggressive traits are not adequately represented by other PDs (Westen, 1997). In this study, 1158 psychiatric outpatients were assessed for Axis I and Axis II disorders. Thirty-five (3.02%) met criteria for NEGPD. Participants with NEGPD did not differ significantly from those without NEGPD on demographic variables. The internal consistency of the DSM-IV's seven NEGPD items was 0.50. Corrected item- total correlations for the 7 criteria averaged 0.27. Participants with NEGPD had higher rates of lifetime anxiety disorders, and almost 90% had an additional PD. An exploratory factor analysis suggested a two- factor solution that accounted for 43.4% of the variance. The first factor reflected the belief that life is unfair, while the second factor seemed to reflect modes of anger expression. A confirmatory factor analysis showed that the two-factor model fit the data better than a unidimensional model. We discuss implications of these results for the future of the NEGPD diagnosis.

Is the appendix a useful appendage? An empirical examination of depressive, passive-aggressive (negativistic), sadistic, and self-defeating personality disorders.

Decisions about whether to include depressive, passive-aggressive, sadistic, and self-defeating disorders in Axis II have been made difficult by a relative dearth of data. We report the results of a study identifying potential defining features of these diagnoses and assessing their distinctiveness from other Axis II personality disorders (PDs). A national sample of experienced psychiatrists and psychologists used the SWAP-200 to describe a patient with a current axis II disorder or an appendix or deleted PD from DSM-II-R. We examined clinicians' descriptions of patients to identify their most characteristic features, and then applied an empirical clustering procedure, Q-factor analysis, to see whether versions of these disorders would emerge empirically. As currently conceptualized, only passive-aggressive PD was distinct from other PDs. When the data were subjected to Q-factor analysis, the first and largest grouping was a dysphoric (depressive) PD. A hostile-negativistic subcategory emerged that resembled passive-aggressive PD, along with a revised dependent diagnosis that included many self-defeating/masochistic features. The results suggest that a depressive or dysphoric personality may represent an internalizing spectrum of personality pathology, and that a hostile-negativistic PD may be distinct from the disorders in the text of DSM-IV. Sadistic and self-defeating PD do not appear to represent distinct disorders, although they include personality traits (sadism and revictimization) associated with distinct developmental histories.

Passive-aggressive personality disorder: the demise of a syndrome.

This article presents an explanation and critique of the rationale for dropping passive-aggressive personality disorder (PAPD) from DSM-IV. The clinical and research literature on PAPD is reviewed along with the historical changes in definition, diagnostic criteria, and usage. PAPD can be reliably diagnosed, is fairly prevalent, and has good internal consistency. Because PAPD is no less valid than other personality disorders, and describes clinical phenomena that are unique among personality disorders, we recommend the reinstatement of PAPD in the official diagnostic nomenclature.

Symptoms of prototypic patients with passive-aggressive personality disorder: DSM-IIIR versus DSM-IV negativistic.

This study examined features of patients that clinicians identified as good examples of Passive-Aggressive Personality Disorder to identify core features of the disorder and to determine which set of criteria (DSM-III-R, two definitions in the DSM-IV Options Book, or DSM-IV Negativistic) best characterized the identified patients. A national sample of licensed psychologists (N = 68) identified a patient who (based on symptoms) was a good example of Passive-Aggressive Personality Disorder. They then rated the patient on a symptom checklist composed of the Passive-Aggressive and Negativistic criteria, as well as other personality-disorder symptoms that overlap with Passive-Aggressive. Clinicians identified patients they considered exemplars for Passive-Aggressive Personality Disorder, and there was moderate consensus about their characteristic symptoms. DSM-III-R symptoms received the highest ratings, and there was little overlap with other personality disorders. Principal-component factor analysis suggested that a general pattern of passive resistance, along with a behavioral manifestation of procrastination and a second group of symptoms suggesting interpersonal difficulties, were the features of these passive-aggressive patients. More male patients were identified as good examples of the disorder, and female patients presented a more heterogeneous diagnostic picture. Implications and directions for future research are discussed, including the need to integrate research findings from the differing perspectives on personality disorders.

Borderline diagnoses.

The author describes the development of the borderline concept and the apparent inaccuracy of the original hypothetical framework. The signs and symptoms used to describe a "borderline syndrome" are often shared with other psychiatric illnesses. The author recommends that clinicians consider patients with only those features as "undiagnosed" until further research determines whether a distinct syndrome exists.