Jennifer L. Tackett

The Hierarchical Taxonomy of Psychopathology (HiTOP) : A Dimensional Alternative to Traditional Nosologies

The reliability and validity of traditional taxonomies are limited by arbitrary boundaries between psychopathology and normality, often unclear boundaries between disorders, frequent disorder co-occurrence, heterogeneity within disorders, and diagnostic instability. These taxonomies went beyond evidence available on the structure of psychopathology and were shaped by a variety of other considerations, which may explain the aforementioned shortcomings. The Hierarchical Taxonomy Of Psychopathology (HiTOP) model has emerged as a research effort to address these problems. It constructs psychopathological syndromes and their components/subtypes based on the observed covariation of symptoms, grouping related symptoms together and thus reducing heterogeneity. It also combines co-occurring syndromes into spectra, thereby mapping out comorbidity. Moreover, it characterizes these phenomena dimensionally, which addresses boundary problems and diagnostic instability. Here, we review the development of the HiTOP and the relevant evidence. The new classification already covers most forms of psychopathology. Dimensional measures have been developed to assess many of the identified components, syndromes, and spectra. Several domains of this model are ready for clinical and research applications. The HiTOP promises to improve research and clinical practice by addressing the aforementioned shortcomings of traditional nosologies. It also provides an effective way to summarize and convey information on risk factors, etiology, pathophysiology, phenomenology, illness course, and treatment response. This can greatly improve the utility of the diagnosis of mental disorders. The new classification remains a work in progress. However, it is developing rapidly and is poised to advance mental health research and care significantly as the relevant science matures.

A unifying perspective on personality pathology across the life span: Developmental considerations for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders

Proposed changes in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) include replacing current personality disorder (PD) categories on Axis II with a taxonomy of dimensional maladaptive personality traits. Most of the work on dimensional models of personality pathology, and on personality disorders per se, has been conducted on young and middle-aged adult populations. Numerous questions remain regarding the applicability and limitations of applying various PD models to early and later life. In the present paper, we provide an overview of such dimensional models and review current proposals for conceptualizing PDs in DSM-V. Next, we extensively review existing evidence on the development, measurement, and manifestation of personality pathology in early and later life focusing on those issues deemed most relevant for informing DSM-V. Finally, we present overall conclusions regarding the need to incorporate developmental issues in conceptualizing PDs in DSM-V and highlight the advantages of a dimensional model in unifying PD perspectives across the life span.

Symptom-based subfactors of DSM-defined conduct disorder: evidence for etiologic distinctions.

Past research investigating the structure of conduct disorder (CD) symptoms has provided evidence of a phenotypic distinction between aggressive and rule-breaking subfactors of CD. However, evidence of etiologic distinctions between these subfactors has not been reported to date. In the current study, the authors investigated this issue in a sample of 1,151 male twins who were 17 years of age. The results indicate that aggressive and rule-breaking CD subfactors have both common and distinct etiologic influences, with shared environmental influences playing a significant role in rule-breaking behaviors. The authors discuss implications of these findings for the assessment and treatment of CD.

A dimensional model of personality disorder: incorporating DSM Cluster A characteristics.

The authors articulate an expanded dimensional model of personality pathology to better account for symptoms of DSM-defined Cluster A personality disorders. Two hundred forty participants (98 first-degree relatives of probands with schizophrenia or schizoaffective disorder, 92 community control participants, and 50 first-degree relatives of probands with bipolar disorder) completed a dimensional personality pathology questionnaire, a measure of schizotypal characteristics, and Chapman measures of psychosis proneness. Scales from all questionnaires were subjected to an exploratory factor analysis with varimax rotation. A 5-factor structure of personality pathology emerged from the analyses, with Peculiarity forming an additional factor to the common 4-factor structure of personality pathology (consisting of Introversion, Emotional Dysregulation, Antagonism, and Compulsivity). These results support a 5-factor dimensional model of personality pathology that better accounts for phenomena encompassed by the Cluster A personality disorders in DSM-IV-TR (4th ed., text revised; American Psychiatric Association, 2000). This study has implications for the consideration of a dimensional model of personality disorder in DSM-V by offering a more comprehensive structural model that builds on previous work in this area.

Subfactors of DSM-IV Conduct Disorder: Evidence and Connections with Syndromes from the Child Behavior Checklist

Is conduct disorder (CD) as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 1994) a unitary entity, or do variants of CD exist? We addressed this question, using data collected from the parents of 1,669 Australian boys, aged 6–17. Parents were interviewed to assess DSM-IV Conduct Disorder (DSM-IV CD) criteria. Results revealed 2 subfactors of DSM-IV CD symptoms, made up of overt behaviors (e.g., initiating physical fights) and covert behaviors (e.g., stealing without confrontation). Ordinary least squares regressions showed the 2 CD subfactors to be significantly and uniquely predicted by Child Behavior Checklist (CBCL; T. M. Achenbach, 1991a, 1991b) syndromes labeled Aggressive Behavior and Delinquent Behavior, respectively. The results are discussed in terms of the utility of differentiating these 2 variants of CD in future editions of the DSM.

The hierarchical structure of childhood personality in five countries: continuity from early childhood to early adolescence.

Childhood personality is a rapidly growing area of investigation within individual differences research. One understudied topic is the universality of the hierarchical structure of childhood personality. In the present investigation, parents rated the personality characteristics of 3,751 children from 5 countries and 4 age groups. The hierarchical structure of childhood personality was examined for 1-, 2-, 3-, 4-, and 5-factor models across country (Canada, China, Greece, Russia, and the United States) and age group (3-5, 6-8, 9-11, and 12-14 years of age). Many similarities were noted across both country and age. The Five-Factor Model was salient beginning in early childhood (ages 3-5). Deviations across groups and from adult findings are noted, including the prominent role of antagonism in childhood personality and the high covariation between Conscientiousness and intellect. Future directions, including the need for more explicit attempts to merge temperament and personality models, are discussed.

Additional Evidence for a Quantitative Hierarchical Model of Mood and Anxiety Disorders for DSM-V: The Context of Personality Structure

Recent progress toward the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders includes a proposed quantitative hierarchical structure of internalizing pathology with substantial, supportive evidence (D. Watson, 2005). Questions about such a taxonomic shift remain, however, particularly regarding how best to account for and use existing diagnostic categories and models of personality structure. In this study, the authors use a large sample of psychiatric patients with internalizing diagnoses (N = 1,319) as well as a community sample (N = 856) to answer some of these questions. Specifically, the authors investigate how the diagnoses of obsessive-compulsive disorder (OCD) and bipolar disorder compare with the other internalizing categories at successive levels of the personality hierarchy. Results suggest unique profiles for bipolar disorder and OCD and highlight the important contribution of a 5-factor model of personality in conceptualizing internalizing pathology. Implications for personality-psychopathology models and research on personality structure are discussed.

The Hierarchical Structure of the Dimensional Assessment of Personality Pathology (DAPP-BQ)

Hierarchical personality models have the potential to identify common and specific components of DSM-IV personality disorders (PDs), and may offer a solution for the re-tooling of personality pathology in future versions of the DSM. In this paper, we examined the hierarchical structure of the Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ; Livesley & Jackson, 2009) and the capacity of various trait components at different levels to predict DSM-IV PD symptoms. Participants were 275 psychiatric outpatients and 365 undergraduate students. Goldbergs (2006) bass-ackwards method was used to investigate the hierarchical structure of the DAPP-BQ. The predictive capacity of hierarchy components was assessed. We found that Level 5 of the hierarchy enhanced the capacity of the DAPP-BQ for predicting DSM PD symptoms beyond a four-factor structure, particularly for borderline PD.

Etiology and measurement of relational aggression: A multi-informant behavior genetic investigation

Although the study of relational aggression is gaining attention in the literature, little is known about the underlying causes of this behavior and the relative validity of various informants. These issues were addressed in a sample of 1,981 6- to 18-year-old twin pairs (36% female, 34% male, 30% opposite-sex). Relational aggression was assessed via maternal and self-report using a structured interview. Univariate models estimated genetic and environmental influences by informant and examined evidence for gender differences. A psychometric model combined data from both informants to estimate etiologic influences that were both common to the informants and informant specific. In both sexes, the latent variable reflecting the mothers and childs shared perception of the childs relational aggression was substantially influenced by both additive genetic (63%) and shared environmental (37%) influences, although this latent variable accounted for much greater variance in the maternal report (66%) than it did in the youth report (9%). In addition, informant-specific additive genetic and shared environmental influences were found only for the youth report, with all remaining variance in the mothers report attributed to nonshared environmental influences. Results are discussed in the context of measuring relational aggression and the importance of multiple informants.

Shared Genetic Influences on Negative Emotionality and Major Depression/Conduct Disorder Comorbidity

OBJECTIVE To investigate whether genetic contributions to major depressive disorder and conduct disorder comorbidity are shared with genetic influences on negative emotionality. METHOD Primary caregivers of 2,022 same- and opposite-sex twin pairs 6 to 18 years of age comprised a population-based sample. Participants were randomly selected across five regions in Tennessee, with stratification by age and geographic location. Face-to-face structured interviews were conducted with the primary caregiver of a representative sample of twins. RESULTS After accounting for genetic influences on negative emotionality, genetic influences on major depressive disorder/conduct disorder comorbidity were nonsignficant, but only in male twins. Specifically, 19% of the variance in the two disorders was accounted for by genetic factors shared with negative emotionality in male twins. Although the full hypothesis could not be tested in female twins, 10% to 11% of the variance in the two disorders was also accounted for by genetic factors shared with negative emotionality. Common shared environmental and nonshared environmental influences were found for major depressive disorder/conduct disorder comorbidity in male and female twins. CONCLUSIONS Negative emotionality represents an important dispositional trait that may explain genetic influences on major depressive disorder/conduct disorder comorbidity, at least for boys. Models of major depressive disorder/conduct disorder comorbidity must simultaneously measure common and specific genetic and environmental factors for a full understanding of this phenomenon. Gender differences require specific research attention in dispositional factors and developmental progression.