The Hierarchical Taxonomy of Psychopathology (HiTOP) in psychiatric practice and research.

The Hierarchical Taxonomy of Psychopathology (HiTOP) has emerged out of the quantitative approach to psychiatric nosology. This approach identifies psychopathology constructs based on patterns of co-variation among signs and symptoms. The initial HiTOP model, which was published in 2017, is based on a large literature that spans decades of research. HiTOP is a living model that undergoes revision as new data become available. Here we discuss advantages and practical considerations of using this system in psychiatric practice and research. We especially highlight limitations of HiTOP and ongoing efforts to address them. We describe differences and similarities between HiTOP and existing diagnostic systems. Next, we review the types of evidence that informed development of HiTOP, including populations in which it has been studied and data on its validity. The paper also describes how HiTOP can facilitate research on genetic and environmental causes of psychopathology as well as the search for neurobiologic mechanisms and novel treatments. Furthermore, we consider implications for public health programs and prevention of mental disorders. We also review data on clinical utility and illustrate clinical application of HiTOP. Importantly, the model is based on measures and practices that are already used widely in clinical settings. HiTOP offers a way to organize and formalize these techniques. This model already can contribute to progress in psychiatry and complement traditional nosologies. Moreover, HiTOP seeks to facilitate research on linkages between phenotypes and biological processes, which may enable construction of a system that encompasses both biomarkers and precise clinical description.

A critical examination of disparities in eating disorder symptoms by sexual orientation among US adults in the NESARC-III.

OBJECTIVE: Sexual minoritized persons evidence higher prevalence of eating disorders than heterosexual persons, yet it is unclear which specific symptoms drive these disparities. Empirical evidence also documents the importance of considering subclinical eating disorder presentations, as well as potential differentiation in expression of eating disorder symptoms based on gender. The current study complements that of Kamody et al. (2020), who examined sexual orientation-based disparities in eating disorder diagnoses using a nationally representative sample of the US adult population. METHOD: Using the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III), we compared the prevalence of eating disorder symptoms across sexual minority status separately for men and women. RESULTS: Sexual minoritized men were more likely than heterosexual men to report body mass index (BMI) < 18.5 kg/m2 (odds ratio [OR] = 1.76), thus, being screened into questions about restrictive eating. Sexual minoritized women were more likely than heterosexual women to endorse ever engaging in a binge-eating episode (OR = 2.25) and engaging in weekly binge eating for at least 3 months (OR = 1.58), thus, being screened into follow-up questions about binge eating. Sexual minoritized men were more likely than heterosexual men to fear gaining weight even when at their lowest weight (OR = 4.35) and experience a loss of control when overeating (OR = 3.13). DISCUSSION: Sexual orientation-based disparities in eating disorder symptom endorsement were nuanced when stratifying the entire sample by gender. Findings expand previous research on disparities in clinical/diagnosed eating disorders, highlighting the importance of assessing symptomology beyond diagnosis, as well as the intersectional influence of sexual orientation and gender, in both research and practice.

Exploring the Optimal Factor Structure of the Five Facet Mindfulness Questionnaire: Associations Between Mindfulness Facets and Dimensions of Psychopathology.

Recent studies of the Five Facet Mindfulness Questionnaire (FFMQ) and its condensed version (FFMQ-SF) fail to replicate the initially proposed five-factor structure in clinical samples. Failure to adequately understand the dimensionality of common mindfulness measures within clinical samples, therefore, represents an important gap in the current literature. The increasing popularity of mindfulness-based interventions warrants further investigation of differential associations between facets of mindfulness and different forms of psychopathology. We examined (a) the underlying structure of the FFMQ and FFMQ-SF, and (b) associations between FFMQ and FFMQ-SF facets and dimensions of psychopathology (i.e., internalizing and substance use disorders) in two large clinical samples (N = 2,779). Results from bass-ackwards analyses suggested similarly defensible five- and six-factor model solutions in terms of fit. The five-factor model was optimal when factoring in parsimony. Exploratory structural equation modeling revealed that all FFMQ facets with the exception of observe were negatively associated with the internalizing factor. Associations with substance use disorders were more complex. In both samples, five-factor FFMQ and FFMQ-SF models were determined to best represent these data. Whereas deficits in all FFMQ facets with the exception of observe correspond with lower internalizing psychopathology, a more nuanced association was observed with substance use disorders.

Physical Health Disparities Across Dimensions of Sexual Orientation, Race/Ethnicity, and Sex: Evidence for Increased Risk Among Bisexual Adults.

Accumulating evidence suggests that sexual minority individuals are at increased risk for physical health conditions compared to heterosexual individuals. However, we know little about physical health disparities affecting bisexual individuals, a population at increased risk for psychiatric and substance use conditions compared to both heterosexual and lesbian/gay populations. Using a large, nationally representative sample, we examined physical health disparities for bisexual individuals. To advance research on sexual minority health disparities, we further: (1) compared prevalence rates of physical health conditions across three dimensions of sexual orientation (i.e., identity, attractions, behavior) and (2) examined whether disparities differed by sex and race/ethnicity. Results indicated that sexual minority individuals were at increased risk for many physical health conditions. Notably, individuals with bisexual identity, attractions, and/or behavior were at increased risk for more physical health conditions than other sexual minority groups. The number and types of physical health disparities affecting bisexually identified individuals and individuals with same- and opposite-sex attractions and/or sexual partners varied across sex and race/ethnicity, with the most consistent disparities emerging for individuals who reported same- and opposite-sex sexual partners. Our findings highlight the substantial physical health disparities affecting sexual minorities and the heightened risk conferred by all facets of bisexuality.

Structural hierarchy of autism spectrum disorder symptoms: an integrative framework.

BACKGROUND: In an attempt to resolve questions regarding the symptom classification of autism spectrum disorder (ASD), previous research generally aimed to demonstrate superiority of one model over another. Rather than adjudicating which model may be optimal, we propose an alternative approach that integrates competing models using Goldberg's bass-ackwards method, providing a comprehensive understanding of the underlying symptom structure of ASD. METHODS: The study sample comprised 3,825 individuals, consecutive referrals to a university hospital developmental disabilities specialty clinic or a child psychiatry outpatient clinic. This study analyzed DSM-IV-referenced ASD symptom statements from parent and teacher versions of the Child and Adolescent Symptom Inventory-4R. A series of exploratory structural equation models was conducted in order to produce interpretable latent factors that account for multivariate covariance. RESULTS: Results indicated that ASD symptoms were structured into an interpretable hierarchy across multiple informants. This hierarchy includes five levels; key features of ASD bifurcate into different constructs with increasing specificity. CONCLUSIONS: This is the first study to examine an underlying structural hierarchy of ASD symptomatology using the bass-ackwards method. This hierarchy demonstrates how core features of ASD relate at differing levels of resolution, providing a model for conceptualizing ASD heterogeneity and a structure for integrating divergent theories of cognitive processes and behavioral features that define the disorder. These findings suggest that a more coherent and complete understanding of the structure of ASD symptoms may be reflected in a metastructure rather than at one level of resolution.

Mental disorder comorbidity and treatment utilization.

OBJECTIVE: Effective interventions have been developed for myriad common psychological and substance use disorders, though they remain highly underutilized. Previous research has shown that the likelihood of treatment utilization varies across disorder diagnosis. However, studies that focus on individual disorders have resulted in a large, piecemeal literature that neglects the high rates of multivariate comorbidity. The current study investigated the association between treatment utilization and transdiagnostic comorbidity factors. METHODS: In a nationally representative sample of the United States adult population (N=34,653), we applied the internalizing-externalizing latent comorbidity model to examine its association with lifetime utilization of various treatments for mood, anxiety, and substance use disorders. RESULTS: Both internalizing and externalizing transdiagnostic factors were positively associated with all forms of treatment utilization. Stronger within-domain domain (e.g., internalizing's association with mood or anxiety treatment) than between-domain (e.g., internalizing's association with substance use disorder treatment) associations were found. Significant antagonistic internalizing-by-externalizing interactions were also observed. CONCLUSIONS: These results underscore the importance of applying a nuanced approach to modeling comorbidity when predicting treatment utilization. Clinical implications are discussed.

Transdiagnostic psychopathology mediates the relationship between childhood sexual abuse and HIV/AIDS and other sexually transmitted infections in adulthood.

Exposure to childhood sexual abuse (CSA) is associated with elevated rates of mental disorders, sexual risk behavior, and sexually transmitted infections (STIs) in adulthood. Mental disorders themselves are associated with an increased risk for HIV/AIDs and STIs as well, and thus may mediate the association between CSA and HIV/AIDS and other STIs. The links among CSA, disorders, and STIs are unclear, however. The current study tested the hypothesis that the association of CSA with STIs is mediated by adult transdiagnostic psychopathology. We examined the potential mediating role of transdiagnostic psychopathology factors-internalizing (INT) and externalizing (EXT)-in the association between CSA and receiving a past-year diagnosis of HIV, AIDS, or another STI in a large, national probability sample of adults (N=34,653). Using indirect effects modeling, we found that 54.4% of the association between CSA and subsequent HIV/AIDS/STI diagnosis operated through transdiagnostic psychopathology. The proposed mediation model was supported, indicating that individuals reporting CSA had higher estimated levels of latent general liabilities for INT and EXT disorders, and it was largely these liabilities that accounted for the link between CSA and heightened risk of adult HIV, AIDS, and STI diagnoses.

Transdiagnostic factors of psychopathology and substance use disorders: a review.

PURPOSE: Research on the structure of mental disorders and comorbidity indicates that many forms of psychopathology and substance use disorders are manifestations of relatively few transdiagnostic latent factors. These factors have important consequences for mental disorder research and applied practice. METHODS: We provide an overview of the transdiagnostic factor literature, with particular focus on recent advances. RESULTS: Internalizing and externalizing transdiagnostic factors have been well characterized in terms of their structures, links with disorders, stability, and statistical properties (e.g., invariance and distributions). Research on additional transdiagnostic factors, such as thought disorder, is quickly advancing latent structural models, as are integrations of transdiagnostic constructs with personality traits. Genetically informed analyses continue to clarify the origins of transdiagnostic factor levels, and links between these factors and important environmental exposures provide promising new avenues of inquiry. CONCLUSIONS: Transdiagnostic factors account for the development and continuity of disorders and comorbidity over time, function as the primary links between disorders and important outcomes such as suicide, mediate associations between environmental exposures and disorders, provide an empirically supported classification system, and serve as foci for efficient, broadband intervention approaches. Overall, transdiagnostic factor research indicates the paramount importance of understanding these constructs and, thereby, broadening our understanding of mental disorder in general.

How Transdiagnostic Factors of Personality and Psychopathology Can Inform Clinical Assessment and Intervention.

Research suggests that many mental disorders-mood and anxiety, substance use, and personality psychopathology-are related through relatively few latent transdiagnostic factors. With regard to the comorbidity of personality disorders and common mental disorders, factor structures such as internalizing-externalizing have been replicated in numerous samples, across the life span, and around the globe. One critical feature of transdiagnostic factors is that they serve as a point of intersection between personality and psychopathology, making them particularly relevant phenomena for applied clinical work. Although numerous studies have supported the significance of transdiagnostic factors for research and classification purposes, there has been comparatively less articulation of how such factors might be of benefit to practicing assessment clinicians. Herein, we present an overview of transdiagnostic factor research findings, and we apply these findings to the clinical topics of assessment, diagnosis, and treatment. For clinicians as well as researchers, the use of transdiagnostic constructs presents positive implications for efforts to understand, characterize, and ameliorate psychopathology-including its manifestations as personality disorder-in a valid, effective, and efficient way.

Investigating differential item functioning among borderline personality disorder diagnostic criteria and internalizing/externalizing domains based on sexual orientation.

Borderline personality disorder (BPD) is more frequently diagnosed among sexual minority (SM) populations. SM populations also report higher levels of internalizing and externalizing psychopathology, two core domains of clinical problems that are highly comorbid with BPD. Contextual factors (e.g., group-specific norms) might affect endorsement of BPD items for reasons other than an underlying liability to experience BPD or internalizing and externalizing psychopathology. Therefore, BPD items may be "easier" to endorse (i.e., be associated with lower indicator thresholds) for SM populations relative to non-SM populations. We tested this hypothesis in a large, nationally representative sample of the U.S. population (N = 35,723, SM n = 1,150) using an item response theory approach. Several BPD indicators demonstrated differential item functioning of indicator thresholds, though these results varied based on impairment and sex. Endorsement of impulsive sex and chronic suicidality were consistently associated with lower indicator thresholds among SM groups; lower BPD, internalizing and externalizing factor levels were necessary for item endorsement for SM individuals. Chronic suicidality and impulsivity criteria may conflate BPD-related variance with SM-specific factors, such as potentially nonpathological SM group norms and minority stress processes. Implications for equitable diagnosis and future research on the BPD syndrome in SM populations are discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

An evaluation of measurement invariance of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition borderline personality disorder criteria across heterosexual, lesbian, gay, and bisexual adults.

There is a robust, yet poorly understood relationship between nonheterosexual orientation and borderline personality disorder (BPD), with lesbian, gay, and bisexual individuals evidencing greater BPD symptoms compared to heterosexual individuals. Recent evidence suggests possible psychometric bias in BPD diagnostic criteria leading to greater endorsement among sexual minority individuals, which hinders researchers' ability to make valid group comparisons. The present study utilized an epidemiological sample of 35,995 men and women to evaluate the extent of differential item functioning (DIF) among BPD criteria across sexual orientation groups using a multiple indicators multiple causes approach. All criteria except affective instability and emptiness indicated DIF for at least one sexual minority focal group, although both demonstrated DIF in sensitivity analyses. DIF was most consistently indicated for suicidality, efforts to avoid abandonment, and impulsivity. Contrary to predictions, DIF was mostly nonuniform with greater item discrimination for sexual minority groups compared to their heterosexual counterparts. Finally, all estimated effect sizes were small, suggesting that DIF was not practically meaningful and unlikely to impact the validity of group comparisons for BPD criteria across heterosexual and nonheterosexual men and women. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Examining Measurement Invariance in the Personality Inventory for DSM-5 Brief Form Across Sexual and Gender Minority Status.

The Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Brief Form (PID-5-BF) was developed with an assumption of invariance across sexual and gender minority (SGM) individuals. This assumption has yet to be tested empirically. Using multigroup confirmatory factor analysis, we examined measurement invariance in the PID-5-BF across the SGM status in clinical (N = 1,174; n = 254 SGM) and nonclinical (N = 1,456; n = 151 SGM) samples. Measurement invariance was supported for the PID-5-BF structure, item thresholds, and factor loadings, but not at the item intercept level. SGM individuals endorsed higher negative affectivity, antagonism, disinhibition, and psychoticism domains in both samples. In the clinical sample, adjusting for partial invariance decreased detachment and antagonism levels for SGM persons. In the nonclinical sample, adjusting for partial invariance reduced antagonism disparities in the SGM group, even rendering original group differences null. Our results support the use of the PID-5-BF in SGM populations but indicate that some measurement bias may drive observed disparities in maladaptive trait domains and, in turn, personality disorder diagnosis.

Measurement invariance of the Child Behavior Checklist (CBCL) across race/ethnicity and sex in the Adolescent Brain and Cognitive Development (ABCD) study.

There are numerous studies examining differences in the experience of disorders and symptoms of psychopathology in adolescents across racial or ethnic groups and sex. Though there is substantial research exploring potential factors that may influence these differences, few studies have considered the potential contribution of measurement properties to these differences. Therefore, this study examined whether there are differences across racial or ethnic groups and sex in the measurement of psychopathology, assessed in mother-reported behavior of 9-11 year old youth from the Adolescent Brain Cognitive Development study sample using updated Child Behavior Checklist scales (CBCL; Achenbach & Rescorla, 2001). Tests of measurement invariance of the CBCL utilized the higher order factor structure identified by Michelini et al. (2019) using this same Adolescent Brain Cognitive Development cohort. The dimensions include internalizing, somatoform, detachment, externalizing, and neurodevelopmental problems. The configural model had a good-to-excellent fit on all subscales of the CBCL across racial or ethnic groups and sex. The metric and scalar models fit just as well as the configural models, indicating that the scales are measuring the same constructs across racial or ethnic groups and sex and are not influenced by measurement properties of items on the CBCL, although some high-severity response options were not endorsed for youth in all racial or ethnic groups. These findings support the use of the CBCL in research examining psychopathology in racially or ethnically diverse samples of youth. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

State of the Science: The Hierarchical Taxonomy of Psychopathology (HiTOP).

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a dimensional framework for psychopathology advanced by a consortium of nosologists. In the HiTOP system, psychopathology is grouped hierarchically from super-spectra, spectra, and subfactors at the upper levels to homogeneous symptom components and maladaptive traits and their constituent symptoms, and maladaptive behaviors at the lower levels. HiTOP has the potential to improve clinical outcomes by planning treatment based on symptom severity rather than heterogeneous diagnoses, targeting treatment across different levels of the hierarchy, and assessing distress and impairment separately from the observed symptom profile. Assessments can be performed according to this framework with the recently developed HiTOP-Self-Report (HiTOP-SR). Examples of how to use HiTOP in clinical practice are provided for the internalizing spectrum, including the use of the Unified Protocol and other modularized treatments, measurement-based care, psychopharmacology, and in traditionally underserved populations. Future directions are discussed in this State of the Science review including HiTOP's use in further developing transdiagnostic treatments, extending the model to include other information such as environmental factors, establishing the treatment utility of clinical assessment for the HiTOP-SR, developing new treatments, and disseminating the model.

Personality disorders research and social decontextualization: What it means to be a minoritized human.

Models of personality disorders have overwhelmingly developed in a socially decontextualized manner. Some historical models of personality pathology formally embraced the interactions between the individual and their environment. However, the field of personality disorder theory, research, and treatment has evolved in a manner that situates dysfunction within intraindividual deficiency processes. By doing so the field limits its applicability to populations that do not represent the norm in clinical psychological science (e.g., sexual/gender minority [SGM] persons for our purposes). Assumptions about personality disorders conflict with evidence-based ways of understanding psychosocial dysfunction among minoritized populations. Using research on SGM populations, and the detrimental impact of minority stress, we demonstrate how sociocultural context is inextricably linked to psychosocial functioning, which remains at odds with personality disorder theory and research. We first briefly review the historical roots of personality disorder theory; explore how sociocultural context is currently instantiated in official nosologies as the Diagnostic and Statistical Manual of Mental Disorders and the Psychodynamic Diagnostic Manual; and illustrate how intraindividual personality disorder conceptualization fails to align with the accepted understanding of how minority stress impacts the health of SGM populations. Finally, we end with a few recommendations for (a) future research on personality disorders and (b) clinical work with SGM individuals who might demonstrate behaviors typically associated with a personality disorder diagnosis. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Is there a bias in the diagnosis of borderline personality disorder among racially minoritized patients?

Empirical evidence documents disparities in the diagnosis of severe forms of psychopathology among racial/ethnic minority persons. However, research on diagnostic differences in personality disorders is equivocal: Some suggest higher prevalence of personality disorders among racial/ethnic minority persons, whereas other results suggest the opposite. The goal of the current study was to investigate (a) differences in the diagnosis of borderline personality disorder (BPD) in a mostly cisgender, heterosexual sample among racial/ethnic minority patients compared with non-Hispanic White patients and (b) whether any observed differences were attributable to differences in underlying maladaptive personality domains. Using data from partial hospital patients (N = 2,657), we found few differences in the diagnosis of BPD based on racial/ethnic group membership. We also conducted measurement invariance analyses of the Personality Inventory for DSM-5-Brief Form (PID-5-BF), finding evidence of invariance across White and non-White participants in these data. Any instances of diagnostic disparity were explained by group differences in maladaptive personality domains. These results provide context to the extant literature documenting mixed results about racial/ethnic differences in prevalence of personality disorders. In addition, they suggest relative specificity in BPD diagnostic bias related to sexual minority populations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Moderators of LGBQ-affirmative cognitive behavioral therapy: ESTEEM is especially effective among Black and Latino sexual minority men.

OBJECTIVE: Lesbian, gay, bisexual, and queer (LGBQ)-affirmative cognitive behavioral therapy (CBT) focused on minority stress processes can address gay and bisexual men's transdiagnostic mental and behavioral health concerns. Identifying moderators of treatment outcomes may inform the mechanisms of LGBQ-affirmative CBT and subpopulations who may derive particular benefit. METHOD: Data were from a clinical trial in which gay and bisexual men with mental and behavioral health concerns were randomized to receive Effective Skills to Empower Effective Men (ESTEEM; an LGBQ-affirmative transdiagnostic CBT; n = 100) or one of two control conditions (n = 154): LGBQ-affirmative community mental health treatment (CMHT) or HIV counseling and testing (HCT). The preregistered outcome was a comorbidity index of depression, anxiety, alcohol/drug problems, and human immunodeficiency virus (HIV) transmission risk behavior at 8-month follow-up (i.e., 4 months postintervention). A two-step exploratory machine learning process was employed for 20 theoretically informed baseline variables identified by study therapists as potential moderators of ESTEEM efficacy. Potential moderators included demographic factors, pretreatment comorbidities, clinical facilitators, and minority stress factors. RESULTS: Racial/ethnic minority identification, namely as Black or Latino, was the only statistically significant moderator of treatment efficacy (B = -3.23, 95% CI [-5.03, -1.64]), t(197) = -3.88, p < .001. Racially/ethnically minoritized recipients (d = -0.71, p < .001), but not White/non-Latino recipients (d = 0.22, p = .391), had greater reductions in comorbidity index scores in ESTEEM compared to the control conditions. This moderation was driven by improvements in anxiety and alcohol/drug use problems. DISCUSSION: Black and Latino gay and bisexual men experiencing comorbid mental and behavioral health risks might particularly benefit from a minority stress-focused LGBQ-affirmative CBT. Future research should identify mechanisms for this moderation to inform targeted treatment delivery and dissemination. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Sociocultural context and the DSM-5 alternative model of personality disorder: Comment on Widiger and Hines (2022).

Widiger and Hines (2022) provide a brief overview of the development of the alternative model of personality disorder (AMPD) housed within Section 3 of the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 2013). They highlight 8 issues and controversies related to the AMPD in need of resolution for improvement of both the AMPD model itself as well as the field of personality disorders more broadly. In this brief commentary, I add a 9th issue in need of attention both with respect to the AMPD but also within the field of personality disorders more broadly: (9) How is sociocultural context to be accommodated in AMPD-and more generally personality disorder-theory, research, and treatment? The historical intraindividual, deficit-based models for conceptualizing personality disorders linger in current personality disorder discourse. However, failure to appropriately consider sociocultural context that systematically predisposes wide swaths of the population to unequal access to resources and exposure to psychological stressors, which can impact the appearance of personality pathology, serves to stigmatize minoritized individuals. The personality disorder field, and the AMPD discourse, must appropriately contend with sociocultural context in its models otherwise it risks developing models with limited generalizability and that hold potential to adversely affect sexual and gender minoritized populations, among others. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

HiTOP Assessment of Externalizing Antagonism and Disinhibition.

This article outlines the Phase 1 efforts of the HiTOP Measure Development group for externalizing constructs, which include disinhibited externalizing, antagonistic externalizing, attention deficit hyperactivity disorder, substance use, and externalizing/maladaptive behaviors. We provide background on the constructs included and the process and issues involved in developing a measure for this diverse range of psychopathology symptoms, traits, and behaviors.

Answering questions about the Hierarchical Taxonomy of Psychopathology (HiTOP): Analogies to whales and sharks miss the boat.

This commentary discusses questions and misconceptions about HiTOP raised by Haeffel et al. (2021). We explain what the system classifies and why it is descriptive and atheoretical, highlighting benefits and limitations of this approach. We clarify why the system is organized according to patterns of covariation or comorbidity among signs and symptoms of psychopathology, and we discuss how it is designed to be falsifiable and revised in a manner that is responsive to data. We refer to the body of evidence for HiTOP's external validity and for its scientific and clinical utility. We further describe how the system is currently used in clinics. In sum, many of Haeffel et al.'s concerns about HiTOP are unwarranted, and for those concerns that reflect real current limitations of HiTOP, our consortium is working to address them, with the aim of creating a nosology that is comprehensive and useful to both scientists and clinicians.