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.

Based on their 2011 meta-analysis of the correlates of the Psychopathic Personality Inventory (PPI), Miller and Lynam (An examination of the Psychopathic Personality Inventory's nomological network: A meta-analytic review, Personality Disorders: Theory, Research, and Treatment, 3, 305-326) conclude that its Fearless Dominance (PPI-FD) higher-order dimension exhibits weak construct validity, leading them to question the relevance of boldness to the conceptualization and assessment of psychopathy. We examine their assertions in light of the clinical, conceptual, and empirical literatures on psychopathy. We demonstrate that Miller and Lynam's assertions (a) are sharply at odds with evidence that well-validated psychopathy measures detect both secondary and primary subtypes, the latter of which is linked to social poise and immunity to psychological distress, (b) are inconsistent with most classic clinical descriptions of psychopathy, in which fearless dominance plays a key role, (c) presume an a priori nomological network of psychopathy that leaves scant room for adaptive functioning and renders psychopathy largely equivalent to antisocial personality disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders, (d) are premised on a misunderstanding of the role of Cleckley's "mask" of healthy adjustment in psychopathy, and (e) are contradicted by data-some reported elsewhere by Miller and Lynam themselves-that PPI-FD is moderately to highly associated with scores on several well-validated psychopathy measures, as well as with personality traits and laboratory markers classically associated with psychopathy. A scientific approach to psychopathy requires the question of whether its subdimensions are linked to adaptive functioning to be adjudicated by data, not by fiat.

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.

This article provides a summary and discussion of major challenges and pitfalls in factor analysis as observed in psychological assessment research, as well as our recommendations within each of these areas. More specifically, we discuss a need to be more careful about item distribution properties in light of their potential impact on model estimation as well as providing a very strong caution against item parceling in the evaluation of psychological test instruments. Moreover, we consider the important issue of estimation, with a particular emphasis on selecting the most appropriate estimator to match the scaling properties of test item indicators. Next, we turn our attention to the issues of model fit and comparison of alternative models with the strong recommendation to allow for theoretical guidance rather than being overly influenced by model fit indices. In addition, since most models in psychological assessment research involve multidimensional items that often do not map neatly onto a priori confirmatory models, we provide recommendations about model respecification. Finally, we end our article with a discussion of alternative forms of model specification that have become particularly popular recently: exploratory structural equation modeling (ESEM) and bifactor modeling. We discuss various important areas of consideration for the applied use of these model specifications, with a conclusion that, whereas ESEM models can offer a useful avenue for the evaluation of internal structure of test items, researchers should be very careful about using bifactor models for this purpose. Instead, we highlight other, more appropriate applications of such models. Public Significance StatementThis article discusses important issues for psychological assessment research using a specific form of statistical analysis: factor analysis. Researchers and the practitioners who consume the research are made aware of common challenges and potential pitfalls in using factor analysis in psychological assessment research as well as recommendations for appropriate decision making.

The current study tested hypotheses associated with the triarchic conceptualization of psychopathy (Patrick, 2010b; Patrick, Fowles, & Krueger, 2009), which describes three distinctive, albeit related, phenotypic domains-boldness, meanness, and disinhibition. We used two samples consisting of 209 female prison inmates and 627 undergraduate students whom had been administered a range of psychopathy and psychopathy-relevant measures. Our results indicated that the triarchic domains explained variance in other psychopathy models to degrees consistent with conceptual expectations. We also examined associations between the triarchic domains and personality traits relevant to psychopathy in the female correctional sample. The results showed that boldness was preferentially associated with narcissism, thrill/adventure seeking, and low behavioral inhibition system functioning; meanness with machiavellianism, low empathy, and low behavioral inhibition system; and disinhibition with impulsivity and fun seeking.