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.

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.

Shortcomings of approaches to classifying psychopathology based on expert consensus have given rise to contemporary efforts to classify psychopathology quantitatively. In this paper, we review progress in achieving a quantitative and empirical classification of psychopathology. A substantial empirical literature indicates that psychopathology is generally more dimensional than categorical. When the discreteness versus continuity of psychopathology is treated as a research question, as opposed to being decided as a matter of tradition, the evidence clearly supports the hypothesis of continuity. In addition, a related body of literature shows how psychopathology dimensions can be arranged in a hierarchy, ranging from very broad "spectrum level" dimensions, to specific and narrow clusters of symptoms. In this way, a quantitative approach solves the "problem of comorbidity" by explicitly modeling patterns of co-occurrence among signs and symptoms within a detailed and variegated hierarchy of dimensional concepts with direct clinical utility. Indeed, extensive evidence pertaining to the dimensional and hierarchical structure of psychopathology has led to the formation of the Hierarchical Taxonomy of Psychopathology (HiTOP) Consortium. This is a group of 70 investigators working together to study empirical classification of psychopathology. In this paper, we describe the aims and current foci of the HiTOP Consortium. These aims pertain to continued research on the empirical organization of psychopathology; the connection between personality and psychopathology; the utility of empirically based psychopathology constructs in both research and the clinic; and the development of novel and comprehensive models and corresponding assessment instruments for psychopathology constructs derived from an empirical approach.

Background Studies of gene-environment (G-E) interplay in the development of psychiatric and substance use disorders are rapidly accumulating. However, few attempts have been made to integrate findings and articulate general mechanisms of G-E influence in the emergence of psychopathology. Objective Identify patterns of G-E interplay between externalizing (EXT; antisocial behavior and substance use) disorders and several environmental risk factors. Design We used quantitative genetic models to examine how genetic and environmental risk for EXT disorders changes as a function of environmental context. Setting Participants were recruited from the community and took part in a day-long assessment at a university laboratory. Participants The sample consisted of 1315 male and female twin pairs participating in the age 17 assessment of the Minnesota Twin Family Study. Main Outcome Measures Multiple measures and informants were employed to construct a composite of EXT disorders and composite measures of 6 environmental risk factors including academic achievement and engagement, antisocial and prosocial peer affiliation, mother-child and father-child relationship problems, and stressful life events. Results A significant G × E interaction was detected between each environmental risk factor and EXT such that greater environmental adversity was associated with increased genetic risk in EXT. Conclusion Our findings demonstrate that in the context of environmental adversity, genetic factors become more important in the etiology of EXT disorders. The consistency of the results further suggests a general mechanism of environmental influence on EXT disorders regardless of the specific form of the environmental risk.

For over a century, research on psychopathology has focused on categorical diagnoses. Although this work has produced major discoveries, growing evidence points to the superiority of a dimensional approach to the science of mental illness. Here we outline one such dimensional system-the Hierarchical Taxonomy of Psychopathology (HiTOP)-that is based on empirical patterns of psychological symptom co-occurrence. We highlight key ways in which this framework can advance mental health research, and we provide some heuristics for using HiTOP to test theories of psychopathology. We then review emerging evidence that supports the value of a hierarchical, dimensional model of mental illness across diverse research areas in psychological science. These new data suggest that the HiTOP system has the potential to accelerate and improve research on mental health problems as well as efforts to more effectively assess, prevent, and treat mental illness.

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a scientific effort to address shortcomings of traditional mental disorder diagnoses, which suffer from arbitrary boundaries between psychopathology and normality, frequent disorder co‐occurrence, heterogeneity within disorders, and diagnostic instability. This paper synthesizes evidence on the validity and utility of the thought disorder and detachment spectra of HiTOP. These spectra are composed of symptoms and maladaptive traits currently subsumed within schizophrenia, other psychotic disorders, and schizotypal, paranoid and schizoid personality disorders. Thought disorder ranges from normal reality testing, to maladaptive trait psychoticism, to hallucinations and delusions. Detachment ranges from introversion, to maladaptive detachment, to blunted affect and avolition. Extensive evidence supports the validity of thought disorder and detachment spectra, as each spectrum reflects common genetics, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, biomarkers, and treatment response. Some of these characteristics are specific to one spectrum and others are shared, suggesting the existence of an overarching psychosis superspectrum. Further research is needed to extend this model, such as clarifying whether mania and dissociation belong to thought disorder, and explicating processes that drive development of the spectra and their subdimensions. Compared to traditional diagnoses, the thought disorder and detachment spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and higher acceptability to clinicians. Validated measures are available to implement the system in practice. The more informative, reliable and valid characterization of psychosis‐related psychopathology offered by HiTOP can make diagnosis more useful for research and clinical care.

Pathological personality is strongly linked with interpersonal impairment, yet, no study to date has examined the relationship between concurrent personality pathology and dysfunction in marriagea relationship most people find central to their lives. In a cross-sectional study of a community sample of married couples (N=82), multilevel modeling was used to estimate the association of self-and spouse reported PD symptoms with levels of marital satisfaction and verbal aggression and perpetration of physical violence. Including self-and spouse report of total PD symptoms resulted in improved model fit and greater variance explained, with much of the improvement coming after the addition of spouse-report. The incremental validity of spouse-report of several of the ten PD scales was supported for marital satisfaction and verbal aggression, particularly for borderline and dependent PD features. Keywords personality disorders; marital adjustment; informants Personality Pathology and Marital AdjustmentThe symptoms that delineate Axis II personality pathology inevitably lead to difficulties in interacting with the interpersonal world. As others have noted, there are aspects of personality disorders (PDs) beyond trouble with relating to others (e.g., chronicity and dysfunction in multiple social roles; Pilkonis, Kim, Proietti, & Barkham, 1999), but a common overriding theme to all disorders is marked impairment in relationships. Indeed, it is well argued that an inability to pursue fundamental adult life tasks, including "close and meaningful intimate relationships" is at the core of the concept of personality disorder (Krueger, Skodol, Livesley, Shrout, & Huang, 2007). There is research linking personality pathology to the most extreme Publisher's Disclaimer:The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors disclaim any responsibility or liabilities for errors or omissions of this manuscript version, any version derived from this manuscript by NIH, or other third parties. The published version is available at http://www.apa.org/journals/ccp/ NIH Public Access forms of maladaptive intimate relationships (i.e., partner violence); yet, there is no study to date that examines more normative measures of marital functioning in relation to PD features. This is a surprising gap considering that these disorders are a collection of cognitive, behavioral, and affective traits which are severe and chronic (American Psychiatric Association, 2000) and that lead to significant impairment in social functioning (Skodol et al., 2002).The current study aims to examine the association between personality disorder symptoms and key features of marital relationships, from satisfaction to verbal conflict and physical violence. Personality pathology is currently represented in the DSM (AP...

Twin studies of personality are consistent in attributing approximately half of the variance in personality to genetic effects, with the remaining variance attributed to environments that make people within the same families different. Such conclusions, however, are based on quantitative models of human individual differences that estimate genetic and environmental contributions as constants for entire populations. Recent advances in statistical modeling allow for the possibility of estimating genetic and environmental contributions contingent on other variables, allowing the quantification of phenomena that have traditionally been characterized as gene-environment interaction and correlation. We applied these newer models to understand how adolescents' descriptions of their relationships with their parents might change or moderate the impact of genetic and environmental factors on personality. We documented notable moderation in the domains of positive and negative emotionality, with parental relationships acting to both enhance and diminish both genetic and environmental effects. We discuss how genetic and environmental contributions to personality might be more richly conceptualized as dynamic systems of gene-environment interplay -systems that are not captured by classical concepts, such as the overall heritability of personality. KeywordsTwin study; Behavior Genetics; Interpersonal Relationships Individual differences are heritable, by which we mean that genetic influences make a substantial contribution to individual differences in peoples' observable characteristics (or "phenotypes"). Indeed, this finding is so universal that Turkheimer (2000) enshrined it as the "first law" of behavior genetics. Turkheimer (2000) went on to propose second and third laws as well. The "second law" states that being raised in the same family has a smaller effect on individual differences than genetic effects. The "third law" is that a nontrivial portion of Correspondence concerning this article should be addressed to Robert F. Krueger, Department of Psychology, University of Minnesota, N414 Elliott Hall, 75 East River Road, Minneapolis, MN 55455−0344. Electronic mail may be sent to krueg038@umn.edu. NIH Public Access NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript individual differences can be attributed to effects unique to each individual person, beyond genetic differences, and also beyond being raised in the same family.These laws are well-supported by an extensive literature, and they clearly apply to personality as much as they apply to other individual differences (for recent reviews of the behavior genetics of personality, see, e.g., Krueger, Johnson & Kling, 2006; Krueger & Johnson, in press). Indeed, these laws have had a fundamental impact on thinking in scientific psychology. Our late colleague David Lykken described the impact of behavior genetic studies as "rearranging the furniture in psychology's house." The "furniture," or the topics of interest in psychology, was not fund...