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Scholarly Works (8 results)

  • Thesis
  • Peer Reviewed
UCLA Electronic Theses and Dissertations (2013)

The current project aimed to determine whether a recently developed explanatory model for comorbidity patterns--labeled the Hierarchical-Spectrum Model (HSM)--could serve as a useful organizing framework for research on psychopathology. The HSM accounts for the high co-occurrence of depressive and anxiety disorders by representing them as facets of an overarching Internalizing dimension; likewise, the substance use and antisocial behavior disorders are represented as facets of an Externalizing dimension. In latent variable modeling terms, the HSM parses the shared and unique variance of disorders into transdiagnostic latent factors (i.e., Internalizing and Externalizing dimensions) and diagnosis-specific residuals, respectively. This project integrated the HSM quantitative structure with prominent genetic and psychosocial theories of psychopathology. Results from Study 1 demonstrated that the relationship of early environmental adversity with psychopathology in young adulthood is partly mediated by the transdiagnostic dimensions. At the same time, early adversity was associated with several residual variances of the HSM, signaling the presence of diagnosis-specific pathways from early adversity to mental disorder. Study 2 conceptualized the stress generation hypothesis, which posits that people with a history of depression, relative to their never-depressed counterparts, experience more stressful life events dependent at least in part on their own behavior, through the lens of the HSM. Results revealed stress generating effects of the Internalizing and Externalizing dimensions, suggesting that the stress generation phenomenon is not specific to any one diagnostic category. Yet, the diagnosis-specific components of major depression and dysthymia also contributed to stress generation over and above the effects of the transdiagnostic dimensions, suggesting there is some pathology unique to depression that confers vulnerability to stress exposure. In Study 3, a daily diary methodology was used to examine day-to-day fluctuations of HSM symptoms. Consistent with expectations, elevated daily stress levels predicted increases in both Internalizing and Externalizing symptoms. Further, a widely studied polymorphism in the serotonin transporter gene (5-HTTLPR) moderated the relationship between daily stress and Internalizing, but not Externalizing, symptoms. Together, the current findings suggest that the HSM has the potential to be a useful framework for research, treatment, and classification in clinical psychology.

    Cover page: A Hierarchical-Spectrum Model of Mental Disorders: Genetic, Developmental, and Interpersonal Perspectives
    • Article
    • Peer Reviewed
    UC Davis Previously Published Works (2018)
    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
      Cover page: Borderline Personality Disorder Is Equally Trait-Like and State-Like Over Ten Years in Adult Psychiatric Patients
      • Article
      • Peer Reviewed
      UCLA Previously Published Works (2014)
      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.
        Cover page: Maximizing exposure therapy: An inhibitory learning approach
        • Article
        • Peer Reviewed
        UC Davis Previously Published Works (2019)
        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.
          Cover page: Criterion A of the AMPD in HiTOP
          • Article
          • Peer Reviewed
          UC Davis Previously Published Works (2019)

          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).
            Cover page: Integrating the Hierarchical Taxonomy of Psychopathology (HiTOP) Into Clinical Practice
            • Article
            • Peer Reviewed
            UC Davis Previously Published Works (2019)
            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.
              Cover page: A Hierarchical Taxonomy of Psychopathology Can Transform Mental Health Research
              • Article
              • Peer Reviewed
              UC Davis Previously Published Works (2020)
              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).
                Cover page: Redefining Phenotypes to Advance Psychiatric Genetics: Implications From Hierarchical Taxonomy of Psychopathology
                • Article
                • Peer Reviewed
                UC Davis Previously Published Works (2018)
                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.
                  Cover page: Enhancing Psychosis-Spectrum Nosology Through an International Data Sharing Initiative.
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