Translating the hierarchical taxonomy of psychopathology (HiTOP) from potential to practice: Ten research questions

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a novel diagnostic system grounded in empirical research into the architecture of mental illness. Its basic units are continuous dimensions-as opposed to categories-that are organized into a hierarchy according to patterns of symptom co-occurrence observed in quantitative studies. Previous HiTOP discussions have focused on existing evidence regarding the model's structure and ability to account for neurobiological, social, cultural, and clinical variation. The present article looks ahead to the next decade of applied research and clinical practice using the HiTOP rubric. We highlight 10 topics where HiTOP has the potential to make significant breakthroughs. Research areas include genetic influences, environmental contributions, neural mechanisms, real-time dynamics, and lifespan development of psychopathology. We also discuss development of novel assessments, forecasting methods, and treatments. Finally, we consider implications for clinicians and educators. For each of these domains, we propose directions for future research and venture hypotheses as to what HiTOP will reveal about psychopathology. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Childhood Traumatic Experiences and Negative Alcohol-Related Consequences in Adulthood: A Cross-Cultural Examination of Distress Tolerance and Drinking to Cope

Background: Prior research has established that Adverse Childhood Experiences (ACEs) predict harmful alcohol use outcomes. However, underlying mechanisms that could explain these associations are less clear. The present study examined if ACEs are indirectly related to alcohol negative consequences through their associations with distress tolerance and drinking to cope. Method: A sample of 3,763 (71.9% female) college students who drink alcohol from seven countries (U.S., Argentina, Canada, Uruguay, Spain, South Africa, and England) completed online surveys. Path analysis was performed within the whole sample testing the serial unique associations between ACEs→distress tolerance→drinking to cope→negative alcohol-related consequences. Multi-group analysis was performed to determine if the proposed pathways were invariant across gender and countries. Results: Both distress tolerance and drinking to cope uniquely accounted for the relationship between ACEs and negative alcohol-related consequences. Additionally, a significant double-mediation effect was found illustrating that a higher endorsement of ACEs was associated with lower distress tolerance, which in turn was associated with higher drinking to cope, which in turn was associated with more negative alcohol-related consequences. These effects were invariant across countries and gender groups. Conclusions: These findings provide support for the relevance of distress tolerance and coping motives as potential factors in linking ACEs to problematic alcohol use across nations. Our data are consistent with the idea that intervening on distress tolerance and drinking motives could mitigate downstream alcohol-related consequences related to ACEs in college student populations around the world.

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 Hierarchical Taxonomy of Psychopathology (HiTOP) Primer for Mental Health Researchers

Mental health research is at an important crossroads as the field seeks more reliable and valid phenotypes to study. Dimensional approaches to quantifying mental illness operate outside the confines of traditional categorical diagnoses, and they are gaining traction as a way to advance research on the causes and consequences of mental illness. The Hierarchical Taxonomy of Psychopathology (HiTOP) is a leading dimensional research paradigm that synthesizes decades of data on the major dimensions of psychological disorders. In this article, we demonstrate how to use the HiTOP model to formulate and test research questions through a series of tutorials. To boost accessibility, data and annotated code for each tutorial are included at OSF (https://osf.io/8myzw). After presenting the tutorials, we outline how investigators can use these ideas and tools to generate new insights in their own substantive research programs.

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.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): III. Emotional dysfunction superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a quantitative nosological system that addresses shortcomings of traditional mental disorder diagnoses, including arbitrary boundaries between psychopathology and normality, frequent disorder co-occurrence, substantial heterogeneity within disorders, and diagnostic unreliability over time and across clinicians. This paper reviews evidence on the validity and utility of the internalizing and somatoform spectra of HiTOP, which together provide support for an emotional dysfunction superspectrum. These spectra are composed of homogeneous symptom and maladaptive trait dimensions currently subsumed within multiple diagnostic classes, including depressive, anxiety, trauma-related, eating, bipolar, and somatic symptom disorders, as well as sexual dysfunction and aspects of personality disorders. Dimensions falling within the emotional dysfunction superspectrum are broadly linked to individual differences in negative affect/neuroticism. Extensive evidence establishes that dimensions falling within the superspectrum share genetic diatheses, environmental risk factors, cognitive and affective difficulties, neural substrates and biomarkers, childhood temperamental antecedents, and treatment response. The structure of these validators mirrors the quantitative structure of the superspectrum, with some correlates more specific to internalizing or somatoform conditions, and others common to both, thereby underlining the hierarchical structure of the domain. Compared to traditional diagnoses, the internalizing and somatoform spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and greater clinical applicability. Validated measures are currently available to implement the HiTOP system in practice, which can make diagnostic classification more useful, both in research and in the clinic.

Higher order compulsivity versus grooming dimensions as treatment targets for the DSM-5 obsessive-compulsive and related disorders

BACKGROUND

Transdiagnostic definitions of obsessive-compulsive and related disorders (OCRDs) may represent useful treatment targets. The current study sought to characterize higher order dimensions underpinning the OCRDs in the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition, and examine their course during treatment.

METHODS

Adult patients (N = 407) completed measures of OCRDs, depression, and worry before and after intensive/residential treatment for OCRDs. Structural equation modeling was used to examine the comorbidity structure and temporal course of the symptoms.

RESULTS

Covariation of the symptoms was best represented by three dimensions: distress (depression and worry), compulsivity (obsessive-compulsive disorder, hoarding, and body dysmorphia), and grooming (hair pulling and skin picking). Latent change score modeling revealed significant reduction in the means of all three dimensions across treatment (Cohen's ds = -1.04, -0.62, and -0.23 for distress, compulsivity, and grooming, respectively). There was a strong correlation between change in compulsivity and grooming (r = .67) and change in compulsivity and distress (r = .80), but a small correlation between change in grooming and distress (r = .35).

CONCLUSIONS

The results indicate that OCRDs are underpinned by higher order compulsivity and grooming dimensions that differ in their association with distress. The results further suggest that the two dimensions may reflect promising intervention targets suitable for transdiagnostic treatment protocols.

Developing Preliminary Scales for Assessing the HiTOP Detachment Spectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is an empirical-based classification of psychopathology. Detachment is one of the six spectra in the current HiTOP working model. The aim of this study was to develop preliminary scales for the HiTOP Detachment spectrum that can be used in the next phase of developing a comprehensive measure of HiTOP. We had 456 participants from MTurk (Sample 1) and 266 university students (Sample 2) complete an online survey including a pool of 247 Detachment items assessing 15 consensually defined low-order constructs. Using a stepwise procedure involving factor analyses and ant colony optimization methods, we developed seven 8-item scales that capture unipolar facets of Detachment: anhedonia, suspiciousness, social withdrawal, intimacy avoidance, unassertiveness, risk aversion, and restricted affectivity. Three other 8-item scales emerged that tapped into a Maladaptive Extraversion construct (attention-seeking, thrill-seeking, and domineering), which was mostly unrelated to unipolar Detachment in factor analyses. The 10 scales were unidimensional, reliable, and showed some evidence of convergent and discriminant validity. We discuss challenges of assessing Detachment when moving forward with developing a comprehensive measure of HiTOP.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): II. Externalizing superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is an empirical effort to address limitations of traditional mental disorder diagnoses. These include arbitrary boundaries between disorder and normality, disorder co-occurrence in the modal case, heterogeneity of presentation within dis-orders, and instability of diagnosis within patients. This paper reviews the evidence on the validity and utility of the disinhibited externalizing and antagonistic externalizing spectra of HiTOP, which together constitute a broad externalizing superspectrum. These spectra are composed of elements subsumed within a variety of mental disorders described in recent DSM nosologies, including most notably substance use disorders and "Cluster B" personality disorders. The externalizing superspectrum ranges from normative levels of impulse control and self-assertion, to maladaptive disinhibition and antagonism, to extensive polysubstance involvement and personality psychopathology. A rich literature supports the validity of the externalizing superspectrum, and the disinhibited and antagonistic spectra. This evidence encompasses common genetic influences, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, and treatment response. The structure of these validators mirrors the structure of the phenotypic externalizing superspectrum, with some correlates more specific to disinhibited or antagonistic spectra, and others relevant to the entire externalizing superspectrum, underlining the hierarchical structure of the domain. Compared with traditional diagnostic categories, the externalizing superspectrum conceptualization shows improved utility, reliability, explanatory capacity, and clinical applicability. The externalizing superspectrum is one aspect of the general approach to psychopathology offered by HiTOP and can make diagnostic classification more useful in both research and the clinic.

Distinguishing Transdiagnostic versus Disorder-Specific Pathways between Ruminative Brooding and Internalizing Psychopathology in Adolescents: A Latent Variable Modeling Approach

Rumination is correlated with diverse types of internalizing problems, but the extent to which it relates to a higher-order internalizing spectrum versus disorder-specific pathology is unclear. Using a quantitative model of the internalizing dimension, we compared the strength of transdiagnostic versus diagnosis-specific pathways from brooding-the most depressogenic component of rumination-to major depressive disorder (MDD) in adolescents. Community-recruited mid-adolescents (N = 241, M_age = 15.90 years, 53% female) completed semi-structured interviews of anxiety and depressive conditions and a self-report brooding measure. Confirmatory factor analysis revealed good fit for a one-factor model of internalizing conditions. Results revealed a large, significant factor correlation between brooding and the internalizing factor (r = 0.55), with some evidence for a more modest specific link between brooding and the unique component of the MDD diagnosis (r = 0.17; approximately one-third as large as the transdiagnostic pathway). These cross-sectional associations were generally consistent across two assessment waves separated by 19 months. We concluded that brooding is better conceptualized as a common characteristic of all internalizing problems in adolescence, rather than a specific feature of MDD. Preregistered hypotheses, data analysis code, and correlation matrices for this study are posted at https://osf.io/dax7u/ .

Rethinking the Diagnosis of Mental Disorders: Data-Driven Psychological Dimensions, Not Categories, as a Framework for Mental-Health Research, Treatment, and Training

Generations of psychologists have been taught that mental disorder can be carved into discrete categories, each qualitatively different from the others and from normality. This model is now outdated. A preponderance of evidence indicates that (a) individual differences in mental health (health vs. illness) are a matter of degree, not kind, and (b) broad mental-health conditions (e.g., internalizing) account for the tendency of narrower ones (e.g., depression, social anxiety, panic) to co-occur. With these observations in mind, we discuss an alternative diagnostic system, called the Hierarchical Taxonomy of Psychopathology (HiTOP), that describes the broad and specific components of mental disorder. It deconstructs traditional diagnostic categories, such as those listed in the Diagnostic and Statistical Manual of Mental Disorders, and recasts them in terms of profiles of dimensions. Recent findings support the utility of this approach for mental-health research and intervention efforts. HiTOP has the potential to put mental-health research, training, and treatment on a much sounder scientific footing.

The comorbidity structure of fear, distress and compulsive disorders in an acute psychiatric sample

Body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD), collectively referred to as compulsive disorders, have typically not been included in structural research on the internalizing spectrum due to low prevalence in community samples. The current study examined the higher-order structure of anxiety, depressive and compulsive disorders among patients in a psychiatric partial hospital program (N = 2,178). We applied confirmatory factor analysis to diagnostic data obtained at admission and compared several competing models of the comorbidity structure. A one-factor model accounted well for the co-occurrence of all the disorders. A two-factor model comprised of fear and distress factors, wherein compulsive disorders loaded on fear, also fit the data well. However, a very large factor correlation (r = 0.86) suggested limited discriminant validity of fear and distress in the sample. Alternate models that featured a distinct compulsivity factor were not viable owing to large correlations between fear and compulsive disorders. Overall, our findings indicate that a broad internalizing dimensions underlies not only anxiety and depression, but also compulsive disorders, in an acute psychiatric population. Future studies using symptom-level data are needed to replicate these results and determine the structure of internalizing disorders from the bottom up, starting with narrowly defined symptom components.

The Hierarchical Taxonomy of Psychopathology (HiTOP): A Quantitative Nosology Based on Consensus of Evidence

Traditional diagnostic systems went beyond empirical evidence on the structure of mental health. Consequently, these diagnoses do not depict psychopathology accurately, and their validity in research and utility in clinicalpractice are therefore limited. The Hierarchical Taxonomy of Psychopathology (HiTOP) consortium proposed a model based on structural evidence. It addresses problems of diagnostic heterogeneity, comorbidity, and unreliability. We review the HiTOP model, supporting evidence, and conceptualization of psychopathology in this hierarchical dimensional framework. The system is not yet comprehensive, and we describe the processes for improving and expanding it. We summarize data on the ability of HiTOP to predict and explain etiology (genetic, environmental, and neurobiological), risk factors, outcomes, and treatment response. We describe progress in the development of HiTOP-based measures and in clinical implementation of the system. Finally, we review outstanding challenges and the research agenda. HiTOP is of practical utility already, and its ongoing development will produce a transformative map of psychopathology.

Threat Conditioning and Trait-Based Vulnerability to Personality Disorder

Some personality disorders (PDs) are accompanied by heightened threat sensitivity to benign events, whereas others are associated with minimal reactivity to danger or punishment. Such aberrant patterns of defensive responding may be due to abnormal threat learning processes, analogous to those observed in other fear- and fearlessness-based disorders. We investigated threat learning deficits with a Pavlovian differential conditioning procedure in an undergraduate sample (n = 117) overselected for negative affectivity. Contrary to predictions, maladaptive personality traits, as assessed via the Personality Inventory for DSM-5, were largely unrelated to defensive responding (i.e., subjective and electrodermal reactions to danger and safety cues) during threat conditioning. We discuss the possible boundary conditions of threat learning abnormalities in PD and suggest research designs that could more effectively reveal such deficits, if they exist.

The Structure of Distress Tolerance and Neighboring Emotion Regulation Abilities

Distress tolerance has fuzzy boundaries with neighboring emotion regulation abilities. In the present study, we probed the structure of this domain and examined its link to emotional disorder outcomes. We recruited mental health patient (ns = 225 and 210) and university student (n = 1,525) samples to report on diverse components of distress tolerance, emotion dysregulation, experiential avoidance, and anxiety sensitivity. Confirmatory factor analysis supported a one-factor model of these individual differences; this broad dimension was closely related to depressive symptoms (standardized effect range = .63 to .74) and suicide risk (.42 to .50), and it was almost perfectly associated with a latent dimension representing borderline personality disorder features (.93-.97). We conclude that a reformulation of this domain-with special attention to discriminant validity-would help understand how distress tolerance is so intimately intertwined with emotional health. The data sets and analysis code for this study are published at https://osf.io/8ab2v/.

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).

Maximizing the applied value of structural models of psychopathology: Introduction to a special issue of Personality and Mental Health

Structural models of mental illness delineate the major phenotypic dimensions of psychopathology. These evidence-based models, such as the Hierarchical Taxonomy of Psychopathology, are poised to supplement-and even supplant-categorical diagnostic systems in research, assessment and treatment arenas. This special issue of Personality and Mental Health explores a new wave of research into structural models' utility for theory testing and clinical practice. Can structural approaches advance etiological research by clarifying connections between psychopathology and social, cultural, psychological and biological vulnerability processes? Can dimensional models of mental illness assimilate consensus models of temperament and personality? Can this paradigm identify optimal treatment targets and guide treatment design and selection? The studies compiled here all look beyond nosology to understand how structural models are changing research and clinical landscapes in mental health disciplines. We envision this set of articles as a blueprint for further investigation into the configuration, research utility and clinical application of structural approaches to diagnostic classification. © 2020 John Wiley & Sons, Ltd.

Redefining phenotypes to advance psychiatric genetics: Implications from hierarchical taxonomy of psychopathology

Genetic discovery in psychiatry and clinical psychology is hindered by suboptimal phenotypic definitions. We argue that the hierarchical, dimensional, and data-driven classification system proposed by the Hierarchical Taxonomy of Psychopathology (HiTOP) consortium provides a more effective approach to identifying genes that underlie mental disorders, and to studying psychiatric etiology, than current diagnostic categories. Specifically, genes are expected to operate at different levels of the HiTOP hierarchy, with some highly pleiotropic genes influencing higher order psychopathology (e.g., the general factor), whereas other genes conferring more specific risk for individual spectra (e.g., internalizing), subfactors (e.g., fear disorders), or narrow symptoms (e.g., mood instability). We propose that the HiTOP model aligns well with the current understanding of the higher order genetic structure of psychopathology that has emerged from a large body of family and twin studies. We also discuss the convergence between the HiTOP model and findings from recent molecular studies of psychopathology indicating broad genetic pleiotropy, such as cross-disorder SNP-based shared genetic covariance and polygenic risk scores, and we highlight molecular genetic studies that have successfully redefined phenotypes to enhance precision and statistical power. Finally, we suggest how to integrate a HiTOP approach into future molecular genetic research, including quantitative and hierarchical assessment tools for future data-collection and recommendations concerning phenotypic analyses. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

A Meta-Structural Model of Common Clinical Disorder and Personality Disorder Symptoms

A large and consistent research literature demonstrates the superiority of dimensional models of mental disorder. Factor analytic research has mapped the latent dimensions underlying separate sets of mental disorders (e.g., emotional disorders), but a common framework-unencumbered by arbitrary historical boundaries between disorder groups-requires additional research. Using empirically derived measures of three key domains of psychopathological variation, the overarching goal of the current study was to explicate dimensions connecting internalizing, externalizing, and personality disorders. Participants included 1,144 racially diverse undergraduates. Exploratory structural equation modeling analyses revealed seven latent dimensions: core internalizing, core externalizing, antagonism, impulsivity, dutifulness, detachment, and suspiciousness. This meta-structure reflects a more comprehensive model of the architecture of mental disorders than accounts derived from less inclusive assessment batteries. Future empirical work is needed to evaluate the utility of this structural model in etiological research, assessment, and treatment arenas.

Cross-Domain Assessment of Distress Intolerance: Associations With Borderline Personality Disorder Features

Distress tolerance (DT) is central to major etiological theories of, and popular treatments for, borderline personality disorder (PD), but empirical evidence for the connection between DT and borderline PD is inconclusive. Such inconsistency is partly due to limited concordance across DT indices from different measurement domains (e.g., behavioral, physiological). In a student sample (N = 267), we assessed subjective perceptions of DT capabilities, task performance on a distressing laboratory challenge, and borderline pathology. Subjective and behavioral indices of DT were largely unrelated. Further, borderline PD features were moderately associated with self-perceived DT (r = -.53); in contrast, they were weakly related to performance on the DT task (r = -.09). We conclude that there is mixed evidence for an association between borderline pathology and DT. Further, we propose a systematic approach to examining the construct validity of DT in multimethod, multimeasure research that might resolve the equivocal results from prior work.

Are fit indices used to test psychopathology structure biased? A simulation study

Structural models of psychopathology provide dimensional alternatives to traditional categorical classification systems. Competing models, such as the bifactor and correlated factors models, are typically compared via statistical indices to assess how well each model fits the same data. However, simulation studies have found evidence for probifactor fit index bias in several psychological research domains. The present study sought to extend this research to models of psychopathology, wherein the bifactor model has received much attention, but its susceptibility to bias is not well characterized. We used Monte Carlo simulations to examine how various model misspecifications produced fit index bias for 2 commonly used estimators, WLSMV and MLR. We simulated binary indicators to represent psychiatric diagnoses and positively skewed continuous indicators to represent symptom counts. Across combinations of estimators, indicator distributions, and misspecifications, complex patterns of bias emerged, with fit indices more often than not failing to correctly identify the correlated factors model as the data-generating model. No fit index emerged as reliably unbiased across all misspecification scenarios. Although, tests of model equivalence indicated that in one instance fit indices were not biased-they favored the bifactor model, albeit not unfairly. Overall, results suggest that comparisons of bifactor models to alternatives using fit indices may be misleading and call into question the evidentiary meaning of previous studies that identified the bifactor model as superior based on fit. We highlight the importance of comparing models based on substantive interpretability and their utility for addressing study aims, the methodological significance of model equivalence, as well as the need for implementation of statistical metrics that evaluate model quality. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

A Hierarchical Taxonomy of Psychopathology Can Transform Mental Health Research

For more than 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 co-occurrence among psychological symptoms. 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.

Distress tolerance trajectories following substance use treatment

OBJECTIVE

Distress tolerance (DT), the ability to withstand aversive internal states, represents an important risk factor for substance use relapse and a potential treatment target. Neurobiological research in substance using populations suggests that continued substance use could erode DT, whereas abstinence could bolster it. The current study characterized trajectories of behavioral and self-reported indices of DT and examined the prospective effect of substance use on DT trajectories among those seeking treatment for substance use.

METHOD

Individuals (N = 263, Mage = 42.68, SD = 11.8, 70.7% male, 94.7% African American) in residential substance use treatment completed subjective (Distress Tolerance Scale) and behavioral (Mirror Tracing Persistence Task-computerized version) DT measures, as well as report of daily substance use (timeline follow-back) over 5 assessment time-points from pretreatment to 12 months posttreatment. Latent curve modeling estimated DT trajectories and their associations with substance use behavior, including abstinence duration (days until first use) and substance use frequency (percentage of substance use days between assessments).

RESULTS

Self-reported and behavioral DT indicators both exhibited positive, nonlinear change over time (standardized slope parameter estimates: Distress Tolerance Scale β = 0.61, p < .01; Mirror Tracing Persistence Task β = 0.34, p < .01). Abstinence duration was associated with greater improvement in behavioral (β = .20, p = .03) DT specifically. Frequency of use was statistically significantly associated with attenuated behavioral DT at 6-month (β = -.12, p = .03) and 12-month follow-ups (β = -.08, p = .045).

CONCLUSIONS

DT appears to improve appreciably posttreatment, and return to substance use may shape the degree of this improvement. Collectively, these findings support the conceptualization of DT as a malleable treatment target and emphasize the benefit of abstinence on improvement in DT. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Ecological validity of a quantitative classification system for mental illness in treatment-seeking adults

Quantitative models of mental illness, such as the Hierarchical Taxonomy of Psychopathology (HiTOP), aim to optimize clinical assessment, which conventionally follows categorical diagnostic rubrics. The evidence base for these models is robust, but also uniform; available data come mostly from structured diagnostic interviews in nationally representative samples. It remains to be seen whether HiTOP adequately reflects mental illness as evaluated in routine clinical care, where diagnosis is often unsystematic and incomplete, relative to controlled research conditions. To test the generalizability of a quantitative nosology to real-world assessment contexts, we fit the HiTOP model to diagnoses in a large sample (N = 25,002) of treatment-seeking university students who were seen by health professionals in everyday practice. We then examined the criterion validity of model components in relation to clinically relevant outcomes (i.e., suicide attempts, self-injury, and binge drinking). Three related structures fit the data well: a correlated-factor model with internalizing, externalizing, and eating pathology dimensions; a higher-order model that added a general factor of psychopathology that spanned these 3 first-order factors; and a bifactor model that partitioned diagnostic (co)variance across a general factor and 3 orthogonal group factors. The first-order factors had expected patterns of criterion validity, and the general factor was a strong predictor of suicidality and self-injury, paralleling past research. Bifactor model group factors had interpretative problems, however. Across models, categorical diagnoses consistently offered minimal incremental validity relative to the transdiagnostic factors. We conclude that HiTOP is ecologically valid-explaining comorbidity patterns among diagnoses assigned "in the field"-and is poised to enhance clinical assessment and decision-making in routine care. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Dynamic associations between borderline personality disorder and stressful life events over five years in older adults

The time course of borderline personality disorder (BPD) is far more variable than traditionally assumed. Shifting environmental conditions are theorized to account, at least in part, for fluctuations in symptom presentation over time. In the present study, we evaluated the reciprocal influences of stressful life events and borderline pathology in a representative community sample of 1,630 older adults assessed 3 times over 5 years. An autoregressive cross-lagged model revealed strong, but imperfect, stability in symptoms of BPD over the study time frame. After adjusting for this continuity in BPD, the prospective effect of life stress on borderline pathology was virtually nil, contrary to expectations. On the other hand, borderline pathology was prospectively related to subsequent dependent event (i.e., stressors to which individuals may have contributed), but not independent event (i.e., fateful stressors), exposure. This pattern of associations was consistent with a stress generation effect. We conclude that stressful life events do not substantially redirect the trajectory of BPD in older adults, possibly owing to inertia of borderline pathology at this developmental stage. Instead, symptoms of BPD seem to promote stress exposure, thereby setting the stage for continued social impairment and comorbid psychiatric problems. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Enhancing Psychosis-Spectrum Nosology Through an International Data Sharing Initiative

The latent structure of schizotypy and psychosis-spectrum symptoms remains poorly understood. Furthermore, molecular genetic substrates are poorly defined, largely due to the substantial resources required to collect rich phenotypic data across diverse populations. Sample sizes of phenotypic studies are often insufficient for advanced structural equation modeling approaches. In the last 50 years, efforts in both psychiatry and psychological science have moved toward (1) a dimensional model of psychopathology (eg, the current Hierarchical Taxonomy of Psychopathology [HiTOP] initiative), (2) an integration of methods and measures across traits and units of analysis (eg, the RDoC initiative), and (3) powerful, impactful study designs maximizing sample size to detect subtle genomic variation relating to complex traits (the Psychiatric Genomics Consortium [PGC]). These movements are important to the future study of the psychosis spectrum, and to resolving heterogeneity with respect to instrument and population. The International Consortium of Schizotypy Research is composed of over 40 laboratories in 12 countries, and to date, members have compiled a body of schizotypy- and psychosis-related phenotype data from more than 30000 individuals. It has become apparent that compiling data into a protected, relational database and crowdsourcing analytic and data science expertise will result in significant enhancement of current research on the structure and biological substrates of the psychosis spectrum. The authors present a data-sharing infrastructure similar to that of the PGC, and a resource-sharing infrastructure similar to that of HiTOP. This report details the rationale and benefits of the phenotypic data collective and presents an open invitation for participation.

Evaluating dimensional models of psychopathology in outpatients diagnosed with emotional disorders: A cautionary tale

BACKGROUND

Mental disorders cluster together systematically. Through factor analysis of disorder comorbidity, investigators are establishing the latent dimensions that underlie the development of related syndromes. However, these dimensions have not been validated across diverse patient samples, in which comorbidity patterns vary widely.

METHOD

We assessed 4,928 outpatients seeking treatment for emotional disorders with a semistructured diagnostic interview. This was the largest patient sample as yet for an evaluation of the latent structure of mental disorders. We compared several competing dimensional models of common mental disorders via confirmatory factor analysis.

RESULTS

The hypothesized confirmatory factor model-anchored by internalizing and externalizing spectra-fit the diagnostic data poorly. Neither a one-factor model, reflecting a unitary liability to all mental disorders, nor a three-factor model, wherein the internalizing dimension bifurcated into distress and fear subfactors, fit appreciably better.

CONCLUSIONS

These data provide novel evidence that the internalizing and externalizing spectra are not structurally sound in all clinical contexts. We speculate about the causes of model misfit and advise additional research into the generalizability-with respect to sample, input data, developmental stage, and more-of dimensional models of mental disorder.

Transdiagnostic pathways from early social stress to psychopathology: a 20-year prospective study

BACKGROUND

Adverse family environments confer susceptibility to virtually all psychiatric problems. This study evaluated two possible models to explain this diversity of associations. Stressful family circumstances during childhood could either activate general, transdiagnostic liabilities to mental disorder or promote numerous disorder-specific liabilities.

METHODS

We recruited a high-risk sample of 815 mother-offspring pairs and assessed social stressors in the family context prospectively from the perinatal period through offspring age 5. We factor analyzed offspring mental disorder diagnoses at age 20 to parse transdiagnostic and disorder-specific dimensions of psychopathology.

RESULTS

Structural analyses revealed nearly equivalent prospective effects of early family stress on overarching Internalizing (β = .30) and Externalizing (β = .29) dimensions. In contrast, there was no evidence of disorder-specific effects.

CONCLUSIONS

Social stressors early in life activate transdiagnostic, and not disorder-specific, liabilities to psychopathology. A focus on higher-order dimensions of psychopathology could accelerate etiological research and intervention efforts for stress-linked mental disorders.

Borderline personality disorder is equally trait-like and state-like over ten years in adult psychiatric patients

Borderline personality disorder (PD) has historically been cast as an unabating condition. Longitudinal data, however, support a more variable time course marked by remission and relapse. In the present study, we tested the possibility that borderline PD has both stable (i.e., consistently present across time and situation, as modern diagnostic systems stipulate) and dynamic (i.e., episodic and situational) elements. Participants were 668 patients from the Collaborative Longitudinal Personality Disorders Study who were administered semistructured diagnostic interviews 5 times over a decade. Trait-state-occasion modeling dissected borderline pathology into time-invariant (i.e., trait) and time-varying (i.e., state) components. Contradicting traditional views of PD intransigence, less than half of borderline PD variability (approximately 45%) was time-invariant (i.e., perfectly stable) over the study timeframe. Furthermore, we found that the time-invariant component of borderline pathology, which we termed borderline proneness, was very closely related (r = .81) to a previously validated Five Factor Model trait composite of borderline features. Moreover, the trait versus state components showed a clear pattern of discriminant validity in relation to several putative causal agents for borderline PD (i.e., environmental pathogens, temperament dimensions). We conclude that borderline pathology contains a stable core and sizable situational components, and that both elements relate systematically to normative personality dimensions and known risk factors. These findings have key implications for etiological research, prognosis, and treatment for borderline PD. (PsycINFO Database Record

Criterion A of the AMPD in HiTOP

The categorical model of personality disorder classification in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (5th ed. [DSM-5]; American Psychiatric Association, 2013 ) is highly and fundamentally problematic. Proposed for DSM-5 and provided within Section III (for Emerging Measures and Models) was the Alternative Model of Personality Disorder (AMPD) classification, consisting of Criterion A (self-interpersonal deficits) and Criterion B (maladaptive personality traits). A proposed alternative to the DSM-5 more generally is an empirically based dimensional organization of psychopathology identified as the Hierarchical Taxonomy of Psychopathology (HiTOP; Kotov et al., 2017 ). HiTOP currently includes, at the highest level, a general factor of psychopathology. Further down are the five domains of detachment, antagonistic externalizing, disinhibited externalizing, thought disorder, and internalizing (along with a provisional sixth somatoform dimension) that align with Criterion B. The purpose of this article is to discuss the potential inclusion and placement of the self-interpersonal deficits of the DSM-5 Section III Criterion A within HiTOP.

Core dimensions of anxiety and depression change independently during adolescence

The developmental trajectories of emotional disorder symptoms during adolescence remain elusive, owing in part to a shortage of intensive longitudinal data. In the present study, we charted the temporal course of the tripartite model of anxiety and depression-which posits an overarching negative affect dimension and specific anhedonia and anxious arousal dimensions-over adolescence and emerging adulthood to construct a developmental map of the core dimensions of emotional disorders. We recruited 604 high school juniors, overselecting those at high risk for emotional disorders, and assessed the tripartite symptom domains 5 times annually. Latent curve modeling revealed that negative affect and anxious arousal declined over follow up, whereas anhedonia did not. Moreover, the correlation in rate of change varied across pairs of symptom domains. Change in negative affect was moderately correlated with change in anxious arousal, but change in anhedonia was not significantly related to change in any other domain. Symptom trajectories, and the pattern of covariation among trajectories, were equivalent across gender and comorbidity status. We discuss implications of these findings for developmental models of anxiety and depression, as well as transdiagnostic frameworks for emotional disorders. (PsycINFO Database Record

Stress responsivity and the structure of common mental disorders: Transdiagnostic internalizing and externalizing dimensions are associated with contrasting stress appraisal biases

Biased stress appraisals critically relate to the origins and temporal course of many-perhaps most-forms of psychopathology. We hypothesized that aberrant stress appraisals are linked directly to latent internalizing and externalizing traits that, in turn, predispose to multiple disorders. A high-risk community sample of 815 adolescents underwent semistructured interviews to assess clinical disorders and naturalistic stressors at ages 15 and 20. Participants and blind rating teams separately evaluated the threat associated with acute stressors occurring in the past year, and an appraisal bias index (i.e., discrepancy between subjective and team-rated threat) was generated. A 2-factor (Internalizing and Externalizing) latent variable model provided an excellent fit to the diagnostic correlations. After adjusting for the covariation between the factors, adolescents' threat overestimation prospectively predicted higher standing on Internalizing, whereas threat underestimation prospectively predicted elevations on Externalizing. Cross-sectional analyses replicated this pattern in early adulthood. Appraisals were not related to the residual portions of any diagnosis in the latent variable model, suggesting that the transdiagnostic dimensions mediated the connections between stress appraisal bias and disorder entities. We discuss implications for enhancing the efficiency of emerging research on the stress response and speculate how these findings, if replicated, might guide refinements to psychological treatments for stress-linked disorders. (PsycINFO Database Record

Seven-Year Course of Borderline Personality Disorder Features: Borderline Pathology Is as Unstable as Depression during Adolescence

Borderline personality disorder (PD) historically is construed as an unremitting condition with poor prognosis. The present study takes a new approach to examining stability and change in borderline PD by explaining symptom expression in terms of an unchanging foundation-termed borderline proneness-on one hand, and transitory influences on the other. We monitored borderline PD symptoms annually in a large sample of high-risk adolescent girls (N = 2,450) from ages 14 to 20. Trait-state-occasion modeling revealed that just over half (52-57%) of borderline PD symptom variation was attributable to fixed borderline proneness, whereas the remainder was subject to change across yearly measurement occasions. This degree of stability was no larger than the corresponding estimate for depression, a condition known for its variable course. Our results indicate that, contrary to its reputation, borderline pathology is not set in stone, and it fluctuates in response to situational influences.

Optimizing Prediction of Psychosocial and Clinical Outcomes With a Transdiagnostic Model of Personality Disorder

Transdiagnostic models hold promise for transforming research and treatment practices for personality disorders (PDs), but widespread acceptance and implementation of such approaches will require persuasive evidence of construct validity and clinical utility. Toward that end, the authors examined the criterion-related validity of a transdiagnostic PD model in relation to psychosocial and clinical outcomes in a high-risk community sample of 700 young adults. Participants and their mothers completed semistructured interviews to assess young adults' PD symptomatology, psychosocial functioning, suicidality, and mental health treatment use. Bifactor modeling revealed an overarching dimension of PD severity-capturing symptoms across all PD categories-that strongly predicted all functional and clinical outcomes in multivariate analyses. Effect sizes for lower-order, specific PD processes were comparatively modest for functional outcomes; however, they provided clinically significant information about suicide risk and treatment use. The authors discuss implications of a transdiagnostic perspective for research on PD etiology, classification, and treatment.

PATHOLOGICAL PERSONALITY TRAITS AND THE NATURALISTIC COURSE OF INTERNALIZING DISORDERS AMONG HIGH-RISK YOUNG ADULTS

BACKGROUND

A personality disorder diagnosis signals a negative prognosis for depressive and anxiety disorders, but the precise abnormal personality traits that determine the temporal course of internalizing psychopathology are unknown. In the present study, we examined prospective associations between abnormal personality traits and the onset and recurrence of internalizing disorders.

METHODS

A sample of 371 young adults at high risk for internalizing problems completed the Schedule for Nonadaptive and Adaptive Personality-Second Edition--a measure of 12 abnormal personality traits and three temperament dimensions (i.e., Negative Temperament, Positive Temperament, Disinhibition vs. Control)--and underwent annual diagnostic interviews over 4 years of follow-up.

RESULTS

In multivariate survival analyses, Negative Temperament was a robust predictor of both new onsets and recurrences of internalizing disorder. Further, the Dependency and Self-Harm abnormal personality dimensions emerged as independent predictors of new onsets and recurrences, respectively, of internalizing disorders after statistically adjusting for variation in temperament.

CONCLUSIONS

Our findings suggest that abnormal personality traits and temperament dimensions have complementary effects on the trajectory of internalizing pathology during young adulthood. In assessment and treatment settings, targeting the abnormal personality and temperament dimensions with the greatest prognostic value stands to improve the early detection of enduring internalizing psychopathology.

Chronic environmental stress and the temporal course of depression and panic disorder: A trait-state-occasion modeling approach

Both acute stressful life events and ongoing strains are thought to confer vulnerability to emotional disorders. Unremitting stressful conditions may be particularly pathogenic, but prior research has struggled to delimit chronic versus transient stressful experiences. We aimed to isolate stable stressors-theorized to be indicators of a latent stress proneness trait-and to examine their effects on the temporal course of depression and panic disorder. We recruited 677 patients diagnosed with an emotional disorder and administered interviews for psychopathology and life stress 3 times over 12-month intervals. Trait-state-occasion modeling revealed that 74% of the variance in life stress was stable over the follow-up period. These stable stressors were associated with a more refractory course of depression and, to a smaller degree, panic disorder over time. In addition, neither gender nor participation in cognitive-behavioral therapy affected the persistence of environmental stress over the study time frame. We discuss implications of these findings for explaining depression recurrence, improving psychological interventions for emotional disorders, and the measurement and evaluation of stress proneness.

Adolescent precursors of adult borderline personality pathology in a high-risk community sample

Longitudinal studies of the exact environmental conditions and personal attributes contributing to the development of borderline personality disorder (BPD) are rare. Furthermore, existing research typically examines risk factors in isolation, limiting our knowledge of the relative effect sizes of different risk factors and how they act in concert to bring about borderline personality pathology. The present study investigated the prospective effects of diverse acute and chronic stressors, proband psychopathology, and maternal psychopathology on BPD features in a high-risk community sample (N = 700) of youth followed from mid-adolescence to young adulthood. Multivariate analyses revealed significant effects of maternal externalizing disorder history, offspring internalizing disorder history, family stressors, and school-related stressors on BPD risk. Contrary to expectations, no interactions between chronically stressful environmental conditions and personal characteristics in predicting borderline personality features were detected. Implications of these findings for etiological theories of BPD and early screening efforts are discussed.

Dysfunctional Attitudes and Affective Responses to Daily Stressors: Separating Cognitive, Genetic, and Clinical Influences on Stress Reactivity

Despite decades of research examining diathesis-stress models of emotional disorders, it remains unclear whether dysfunctional attitudes interact with stressful experiences to shape affect on a daily basis and, if so, how clinical and genetic factors influence these associations. To address these issues, we conducted a multi-level daily diary study that examined how dysfunctional attitudes and stressful events relate to daily fluctuations in negative and positive affect in 104 young adults. Given evidence that clinical and genetic factors underlie stress sensitivity, we also examined how daily affect is influenced by internalizing and externalizing symptoms and brain-derived neurotrophic factor (BDNF) genotype, which have been shown to influence neural, endocrine, and affective responses to stress. In multivariate models, internalizing symptoms and BDNF Val66Met genotype independently predicted heightened negative affect on stressful days, but dysfunctional attitudes did not. Specifically, the BDNF Met allele and elevated baseline internalizing symptomatology predicted greater increases in negative affect in stressful circumstances. These data are the first to demonstrate that BDNF genotype and stress are jointly associated with daily fluctuations in negative affect, and they challenge the assumption that maladaptive beliefs play a strong independent role in determining affective responses to everyday stressors. The results may thus inform the development of new multi-level theories of psychopathology and guide future research on predictors of affective lability.

Maximizing exposure therapy: an inhibitory learning approach

Exposure therapy is an effective approach for treating anxiety disorders, although a substantial number of individuals fail to benefit or experience a return of fear after treatment. Research suggests that anxious individuals show deficits in the mechanisms believed to underlie exposure therapy, such as inhibitory learning. Targeting these processes may help improve the efficacy of exposure-based procedures. Although evidence supports an inhibitory learning model of extinction, there has been little discussion of how to implement this model in clinical practice. The primary aim of this paper is to provide examples to clinicians for how to apply this model to optimize exposure therapy with anxious clients, in ways that distinguish it from a 'fear habituation' approach and 'belief disconfirmation' approach within standard cognitive-behavior therapy. Exposure optimization strategies include (1) expectancy violation, (2) deepened extinction, (3) occasional reinforced extinction, (4) removal of safety signals, (5) variability, (6) retrieval cues, (7) multiple contexts, and (8) affect labeling. Case studies illustrate methods of applying these techniques with a variety of anxiety disorders, including obsessive-compulsive disorder, posttraumatic stress disorder, social phobia, specific phobia, and panic disorder.

Daily stress reactivity and serotonin transporter gene (5-HTTLPR) variation: internalizing responses to everyday stress as a possible transdiagnostic phenotype

Background

Recent studies examining the interaction between the 5-HTTLPR locus in the serotonin transporter gene and life stress in predicting depression have yielded equivocal results, leading some researchers to question whether 5-HTTLPR variation indeed regulates depressive responses to stress. Two possible sources of inconsistent data in this literature are imprecise stress assessment methodologies and a restricted focus on depression phenotypes as the outcome of interest, as opposed to transdiagnostic emotional symptoms such as internalizing and externalizing dimensions. The present study aimed to address these critical limitations in prior research by examining how 5-HTTLPR acts in concert with idiographically assessed daily life stress to predict transdiagnostic emotional outcomes.

Results

One hundred and four healthy young adults genotyped for 5-HTTLPR reported on their life stress exposure and internalizing and externalizing experiences for 14 consecutive days. As hypothesized, daily stress levels were associated with severity of internalizing symptoms, but only for 5-HTTLPR S allele carriers. Additional analyses revealed that these interactive effects of 5-HTTLPR and daily life stress on internalizing symptoms extended to both the distress and fear subdomains of internalizing symptoms.

Conclusions

Considered together, these results support the validity of the 5-HTTLPR stress sensitivity hypothesis and suggest for the first time that variation at 5-HTTLPR moderates the effects of daily life stress on broadband symptom profiles.

Transdiagnostic and disorder-specific models of intergenerational transmission of internalizing pathology

BACKGROUND

Numerous studies have supported an association between maternal depression and child psychiatric outcomes, but few have controlled for the confounding effects of both maternal and offspring co-morbidity. Thus, it remains unclear whether the correspondence between maternal and offspring depressive and anxiety disorders is better explained by associations between shared features of maternal and offspring internalizing disorders or by specific effects exerted by unique aspects of individual disorders.

METHOD

Pairs of mothers and offspring overselected for maternal depression (n = 815) were assessed at offspring age 15 years for anxiety and depressive disorders; 705 completed a follow-up at offspring age 20 years. For both mothers and offspring, structural equation modeling was used to distinguish transdiagnostic internalizing pathology--representing the overlap among all depressive and anxiety disorders--from diagnosis-specific forms of pathology. To discriminate between general versus specific pathways of intergenerational transmission of psychopathology, we examined (a) the general association between the maternal and offspring internalizing factors and (b) the correlations between maternal and offspring diagnosis-specific pathology for each disorder.

RESULTS

For mothers and offspring, a unidimensional latent variable model provided the best fit to the correlations among depressive and anxiety disorders. The maternal transdiagnostic internalizing factor strongly predicted the corresponding factor among offspring. In addition, the unique component of post-traumatic stress disorder among offspring was significantly related to the analogous unique component among mothers, but specific components of other maternal disorders, including depression, did not predict corresponding offspring pathology.

CONCLUSIONS

Results suggest that intergenerational transmission of internalizing disorders is largely non-specific.

Gender composition of preadolescents' friendship groups moderates peer socialization of body change behaviors

OBJECTIVE

Peer socialization may be an important contributor to the rising prevalence of diet and muscle gain behaviors (i.e., body change behaviors) in adolescence. The present study longitudinally examined body change behaviors in preadolescents' friendship groups as predictors of preadolescents' own body change behaviors. It was predicted that peer socialization effects would vary according to the gender composition of preadolescents' friendship group.

METHOD

Participants (N = 648, 48.8% female) were in grades 6 through 8 at Time 1 and reported their dieting and muscle-gaining behavior at three time points approximately 1 year apart. Friendship groups were identified from preadolescents' friendship nominations. Body mass index and pubertal timing were included in analyses as control variables. A multiple group latent growth curve model was used to examine hypotheses.

RESULTS

Socialization of body change behaviors in preadolescent friendship groups was observed only under certain conditions. For members of all-male friendship groups, preadolescents' dieting trajectories were predicted from friends' average level of dieting.

CONCLUSION

Peer socialization effects are associated with trajectories of preadolescents' body change behaviors, particularly among all-male groups. Future research would benefit from incorporating the friendship group context into the study of health risk behaviors in preadolescents.

Expanding stress generation theory: test of a transdiagnostic model

Originally formulated to understand the recurrence of depressive disorders, the stress generation hypothesis has recently been applied in research on anxiety and externalizing disorders. Results from these investigations, in combination with findings of extensive comorbidity between depression and other mental disorders, suggest the need for an expansion of stress generation models to include the stress generating effects of transdiagnostic pathology as well as those of specific syndromes. Employing latent variable modeling techniques to parse the general and specific elements of commonly co-occurring Axis I syndromes, the current study examined the associations of transdiagnostic internalizing and externalizing dimensions with stressful life events over time. Analyses revealed that, after adjusting for the covariation between the dimensions, internalizing was a significant predictor of interpersonal dependent stress, whereas externalizing was a significant predictor of noninterpersonal dependent stress. Neither latent dimension was associated with the occurrence of independent, or fateful, stressful life events. At the syndrome level, once variance due to the internalizing factor was partialed out, unipolar depression contributed incrementally to the generation of interpersonal dependent stress. In contrast, the presence of panic disorder produced a "stress inhibition" effect, predicting reduced exposure to interpersonal dependent stress. Additionally, dysthymia was associated with an excess of noninterpersonal dependent stress. The latent variable modeling framework used here is discussed in terms of its potential as an integrative model for stress generation research.

Coaction of stress and serotonin transporter genotype in predicting aggression at the transition to adulthood

Despite consistent evidence that serotonin functioning affects stress reactivity and vulnerability to aggression, research on serotonin gene-stress interactions (G × E) in the development of aggression remains limited. The present study investigated variation in the promoter region of the serotonin transporter gene (5-HTTLPR) as a moderator of the stress-aggression association at the transition to adulthood. Multiple informants and multiple measures were used to assess aggression in a cohort of 381 Australian youth (61% female, 93% Caucasian) interviewed at ages 15 and 20. At age 20, semistructured interviews assessed acute and chronic stressors occurring in the past 12 months. Structural equation modeling analyses revealed a significant main effect of chronic stress, but not 5-HTTLPR or acute stress, on increases in aggression at age 20. Consistent with G × E hypotheses, 5-HTTLPR short allele carriers demonstrated greater increments in aggression following chronic stress relative to long allele homozygotes. The strength of chronic stress G × E did not vary according to sex. Variation at 5-HTTLPR appears to contribute to individual differences in aggressive reactions to chronic stress at the transition to adulthood.