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.

Les progrès dans la réalisation de la classification quantitative de la psychopathologie.

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.

The Aspirations for a Paradigm Shift in DSM-5: An Oral History.

The initial plans for the DSM-5 revision envisioned a paradigm shift away from traditional diagnostic categories. However, plans for a major move from descriptive to etiologic diagnoses were quickly abandoned as infeasible. Support was much broader for adding dimensional/spectrum constructs to the categorical diagnoses, although this was interpreted in various ways. Delegation of substantial autonomy to work groups with modest central coordination was seen as problematic by some work groups and positively by others. Controversies emerged around the standards for diagnostic change, and the degree to which the same standards should be used across diagnostic groups. The Summit Group was given the final task of trying to forge a consensus among the various review groups. We conclude with thoughts about the difficulty of trying to revise an entire manual all at once and the desirability of developing clear rules for change at the outset of such a diagnostic project.

APIRE Practice Research Network: accomplishments, challenges, and lessons learned.

The Practice Research Network (PRN) was established in 1993 to bridge the gap between the science base and the clinical practice of psychiatry by expanding the generalizability of findings and involving clinicians in the development and conduct of research. It began as a nationwide network of psychiatrists and has evolved to conduct large-scale, clinical and policy research studies using randomly selected samples of psychiatrists from the AMA Physician Masterfile. This paper provides an overview of major PRN initiatives and the impact of these studies. It describes the benefits to clinicians of participating in PRN research, as well as strategies developed to address key challenges.

A Crosswalk Study of DSM-IV and DSM-5 Criteria for PTSD from the DSM-5 Field Trials.

Objective: Posttraumatic stress disorder (PTSD) is prevalent and sometimes severely disabling. Providing effective treatment for PTSD and addressing its social consequences require accurate diagnosis. PTSD criteria have changed in all editions of the American Diagnostic Criteria since introduction of the diagnosis in DSM-III in 1980. The DSM-5 Field Trials demonstrated very good inter-rater reliability for PTSD, but a crosswalk study comparing DSM-IV and DSM-5 criteria has potential to identify diagnostic differences generated by changed criteria. Methods: A DSM-IV to DSM-5 PTSD crosswalk study was conducted in real-world adult clinical treatment settings in two DSM-5 Field Trials sites, the Dallas (N = 93) and Houston (N = 48) Veterans Affairs medical centers. The crosswalk assessment was conducted by trained clinicians who interviewed the patients and rated both sets of criteria on a combined checklist. Results: PTSD prevalence differed insubstantially between criteria sets (42% vs. 45% and 55% vs. 52% in the Dallas and Houston sites, respectively), with moderate to excellent diagnostic agreement (reliability indicated, respectively, by κ = .53 and .93); however, substantial proportions of individuals diagnosed in one criteria set did not meet criteria in the other. Differences in cross-criteria diagnostic reliability were largely a function of differing definitions of criterion A trauma. Conclusions: Reliability across the two criteria sets was generally good to excellent, and diagnostic discrepancy predominantly reflected the elimination of criterion A2 in DSM-5 with a smaller contribution from changes to the avoidance and numbing criteria.

Obsessive-compulsive behavior spectrum: refining the research agenda for DSM-V.

The American Psychiatric Association, in collaboration with the World Health Organization and the National Institutes of Health, has undertaken a 5-year international research planning effort in preparation for the formal revision of the Diagnostic and Statistical Manual of Mental Disorders. One element of the project was a conference titled "Obsessive-Compulsive Behavior Spectrum," in which participants reviewed an array of disorders that cross current diagnostic categories. Questions raised challenge those responsible for the DSM-V revision to assess the pros and cons of changing definitions, boundaries, or linkages among diverse conditions characterized by obsessive-compulsive behaviors in the revised classification.

Integrating the Hierarchical Taxonomy of Psychopathology (HiTOP) into clinical practice.

OBJECTIVE: Diagnosis is a cornerstone of clinical practice for mental health care providers, yet traditional diagnostic systems have well-known shortcomings, including inadequate reliability, high comorbidity, and marked within-diagnosis heterogeneity. The Hierarchical Taxonomy of Psychopathology (HiTOP) is a data-driven, hierarchically based alternative to traditional classifications that conceptualizes psychopathology as a set of dimensions organized into increasingly broad, transdiagnostic spectra. Prior work has shown that using a dimensional approach improves reliability and validity, but translating a model like HiTOP into a workable system that is useful for health care providers remains a major challenge. METHOD: The present work outlines the HiTOP model and describes the core principles to guide its integration into clinical practice. RESULTS: Potential advantages and limitations of the HiTOP model for clinical utility are reviewed, including with respect to case conceptualization and treatment planning. A HiTOP approach to practice is illustrated and contrasted with an approach based on traditional nosology. Common barriers to using HiTOP in real-world health care settings and solutions to these barriers are discussed. CONCLUSIONS: HiTOP represents a viable alternative to classifying mental illness that can be integrated into practice today, although research is needed to further establish its utility. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Use of depot antipsychotic medications for medication nonadherence in schizophrenia.

OBJECTIVES: To describe factors associated with initiation of depot antipsychotic medications in psychiatric outpatients with schizophrenia and recent medication nonadherence. METHODS: A national sample of psychiatrists reported on adult outpatients with schizophrenia who were nonadherent with oral antipsychotic medications in the last year. RESULTS: In total, 17.6% of psychiatrists initiated depot antipsychotic injections. Initiation was significantly and positively associated with public insurance, prior inpatient admission, proportion of time nonadherent, average or above average intellectual functioning, and living in a mental health residence. Use was inversely associated with using second-generation antipsychotics and other oral psychotropic medications prior to medication nonadherence. Psychiatrists who were male, nonwhite, and more optimistic about managing nonadherence were more likely to initiate depot injections. CONCLUSIONS: Initiation of depot injections is a joint function of patient, physician, treatment, and setting factors. Use of long-acting preparations in this population is uncommon despite clinical recommendations urging their use.

Medicare Part D prescription drug benefits and administrative burden in the care of dually eligible psychiatric patients.

OBJECTIVE: With implementation of Medicare Part D, concerns were raised that patients with severe mental illness who were dually eligible for both Medicaid and Medicare benefits would be at clinical risk. In addition to concerns about medication access and continuity, there were concerns about administrative burden for physicians and their staffs. This study aimed to quantify the amount of administrative burden for psychiatrists and their staff related to Medicare Part D prescription drug plan administration in a national sample of dually eligible psychiatric patients and to identify factors associated with increased burden. METHODS: A total of 5,833 psychiatrists were randomly selected from the American Medical Association's Physicians Masterfile. Responses were obtained from 64% (N=3,247) with a mailed survey using practice-based survey research methods during the first four months of Medicare Part D implementation (January to April 2006); 1,183 psychiatrists met eligibility requirements. RESULTS: Psychiatrists and their staff spent 45 minutes in administrative tasks for every one hour of direct patient care for dually eligible patients. Drug plan features, including prior authorization and preferred drug formularies, and medication access problems were associated with increased administrative time. CONCLUSIONS: Results of this study indicate several drug plan features and medication access problems related to Part D implementation were associated with significant increases in administrative burden for psychiatrists and their staff, which may result in less time for direct patient care. Given the vulnerability of this high-risk population, this increased administrative burden may pose a significant risk to the overall quality of care for psychiatric patients.

Family contact and the management of medication non-adherence in schizophrenia.

We compare psychiatric management of antipsychotic non-adherence among schizophrenia outpatients with high and low levels of family contact. A national survey was conducted among a random sample of psychiatrists treating schizophrenia, providing data on 310 patients. Patients were stratified by level of family contact. Psychiatrists were more likely to use family interventions to manage non-adherence among patients with high family contact. Psychiatrists were significantly more likely to change antipsychotic dosing in patients with high family contact, though less likely to start depot antipsychotic medications. Family interventions appear to be commonly used in the psychiatric management of medication non-adherence in schizophrenia.

Progress in achieving quantitative classification of psychopathology.

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.

Medication access and continuity: the experiences of dual-eligible psychiatric patients during the first 4 months of the Medicare prescription drug benefit.

OBJECTIVE: This study attempted to systematically assess the experiences of Medicare and Medicaid "dual-eligible" psychiatric patients, including evaluating patients' access to medications and the administrative functioning of the program, during the first 4 months of the Medicare Part D prescription drug benefit. METHOD: Psychiatrists (N=5,833) were randomly selected from the American Medical Association's Physicians Masterfile. After exclusion of those not practicing and with undeliverable addresses, 64% responded; 35% met study eligibility criteria of treating at least one dual-eligible patient during their last typical workweek and reported clinically detailed information on one systematically selected patient. RESULTS: A total of 53.4% had at least one medication access problem to report between Jan. 1 and April 30, 2006. Although 9.7% experienced improved medication access, 22.3% discontinued or temporarily stopped taking medication because of prescription drug coverage or management issues, and 18.3% were previously stable but were required to switch medications. Among those with medication access problems, 27.3% experienced a significant adverse clinical event; 19.8% had an emergency room visit. Most drug plan features studied, including preferred drug/formulary lists, prior authorization, medication dosing/number limits, "fail-first" protocols, and requirements to switch to generics, were associated with significantly higher rates of medication access problems. CONCLUSIONS: The findings indicate consequential medication access problems for psychiatric patients during the implementation of Medicare Part D. Although Centers for Medicare and Medicaid Services policies were enacted to ensure access to protected classes of psychopharmacologic medications, the high rates of medication access problems observed indicate further refinement of these policies is needed.

Dimensional approaches to psychiatric classification: refining the research agenda for DSM-V: an introduction.

The American Psychiatric Association (APA) will publish the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V), in 2012. This paper reviews the extended, multi-faceted research planning preparations that APA has undertaken, several in collaboration with the World Health Organization and the U.S. National Institutes of Health, to assess the current state of diagnosis-relevant research and to generate short- and long-term recommendations for research needed to enrich DSM-V and future psychiatric classifications. This research review and planning process has underscored widespread interest among nosologists in the US and globally regarding the potential benefits for research and clinical practice of incorporating a dimensional component into the existing categorical, or binary, classification system in the DSM. Toward this end, the APA and its partners convened an international conference in July 2006 to critically appraise the use of dimensional constructs in psychiatric diagnostic systems. Resultant papers appear in this issue of International Journal of Methods in Psychiatric Research and in a forthcoming monograph to be published by APA.

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. (PsycINFO Database Record

Report by the ACNP Task Force on response and remission in major depressive disorder.

This report summarizes recommendations from the ACNP Task Force on the conceptualization of remission and its implications for defining recovery, relapse, recurrence, and response for clinical investigators and practicing clinicians. Given the strong implications of remission for better function and a better prognosis, remission is a valid, clinically relevant end point for both practitioners and investigators. Not all depressed patients, however, will reach remission. Response is a less desirable primary outcome in trials because it depends highly on the initial (often single) baseline measure of symptom severity. It is recommended that remission be ascribed after 3 consecutive weeks during which minimal symptom status (absence of both sadness and reduced interest/pleasure along with the presence of fewer than three of the remaining seven DSM-IV-TR diagnostic criterion symptoms) is maintained. Once achieved, remission can only be lost if followed by a relapse. Recovery is ascribed after at least 4 months following the onset of remission, during which a relapse has not occurred. Recovery, once achieved, can only be lost if followed by a recurrence. Day-to-day functioning and quality of life are important secondary end points, but they were not included in the proposed definitions of response, remission, recovery, relapse, or recurrence. These recommendations suggest that symptom ratings that measure all nine criterion symptom domains to define a major depressive episode are preferred as they provide a more certain ascertainment of remission. These recommendations were based largely on logic, the need for internal consistency, and clinical experience owing to the lack of empirical evidence to test these concepts. Research to evaluate these recommendations empirically is needed.

Patterns of adult psychotherapy in psychiatric practice.

OBJECTIVE: Psychotherapy has long been recognized as a key component of psychiatric care. However, concerns have been raised about access to psychotherapy as a result of changes in the financing and management of care. This study examined patterns and predictors of receipt of psychotherapy among patients of psychiatrists. METHODS: Data were collected for 587 psychiatrists who participated in the American Psychiatric Institute for Research and Education's Practice Research Network 1999 Study of Psychiatric Patients and Treatments, which generated nationally representative data for 1,589 adult patients. RESULTS: Findings indicate that more than 66 percent of patients of psychiatrists received some form of psychotherapy from the psychiatrist or another provider in the past 30 days--56 percent from their psychiatrist and 10 percent from another clinician. Although 72 percent of patients with depression received psychotherapy, more than half of those with schizophrenia did not. CONCLUSIONS: A majority of patients of psychiatrists received psychotherapy from their psychiatrist. However, these rates varied by demographic, diagnostic, and health plan characteristics and by practice setting. Further research determining if these observed patterns of psychotherapy are related to differential outcomes is needed.

Revised prevalence estimates of mental disorders in the United States: using a clinical significance criterion to reconcile 2 surveys' estimates.

BACKGROUND: Current US mental disorder prevalence estimates have limited usefulness for service planning and are often discrepant. Data on clinical significance from the National Institute of Mental Health Epidemiologic Catchment Area Program (ECA) and the National Comorbidity Survey (NCS) were used to produce revised estimates, for more accurate projections of treatment need and further explication of rate discrepancies. METHODS: To ascertain the prevalence of clinically significant mental disorders in each survey, responses to questions on life interference from, telling a professional about, or using medication for symptoms were applied to cases meeting symptom criteria in the ECA (n = 20,861) and NCS (n = 8098). A revised national prevalence estimate was made by selecting the lower estimate of the 2 surveys for each diagnostic category, accounting for comorbidity, and combining categories. RESULTS: Using data on clinical significance lowered the past-year prevalence rates of "any disorder" among 18- to 54-year-olds by 17% in the ECA and 32% in the NCS. For adults older than 18 years, the revised estimate for any disorder was 18.5%. Using the clinical significance criterion reduced disparities between estimates in the 2 surveys. Validity of the criterion was supported by associations with disabilities and suicidal behavior. CONCLUSIONS: Establishing the clinical significance of disorders in the community is crucial for estimating treatment need. More work should be done in defining and operationalizing clinical significance, and characterizing the utility of clinically significant symptoms in determining treatment need even when some criteria of the disorder are not met. Discrepancies in ECA and NCS results are largely due to methodologic differences.

Concomitant pharmacotherapy among youths treated in routine psychiatric practice.

OBJECTIVES: The aim of this study was to assess rates and correlates of concomitant pharmacotherapy in children and adolescents treated by psychiatrists in a broad range of clinical settings. METHODS: Cross-sectional data on 392 child and adolescent patients aged 2-17 years from the 1997 and 1999 American Psychiatric Practice Research Network Study of Psychiatric Patients and Treatments were used, and weighted estimates are provided. RESULTS: Findings indicate that 84% of child and adolescent patients received one or more psychopharmacologic medications; 52% of patients treated with medications received concomitant pharmacotherapy (i.e., two or more medications). Patients who were treated with psychopharmacologic treatments received a median of 2 medications (range, 1-6). Highest rates of concomitant pharmacotherapy were among patients with bipolar disorder (87%). Correlates of concomitant pharmacotherapy included: (1) having a diagnosis of bipolar disorder, (2) having co-occurring Axis I or II disorders or general medical conditions, and (3) currently receiving treatment in an inpatient setting. CONCLUSIONS: Over 40% of child and adolescent patients of psychiatrists were prescribed two or more psychopharmacologic medications. Patients with chronic and clinically complex conditions were more likely to receive concomitant pharmacotherapy. Most often, efficacy of U.S. Food and Drug Administration (FDA)-approved medications has been examined as monotherapy, and cautions on drug interactions and off-label use derived from multiple sources accompany each product. With high rates of concomitant pharmacotherapy among children and adolescents in psychiatric care, additional research on efficacy and safety of this treatment strategy is necessary.