Hierarchical taxonomy of psychopathology across development: Associations with personality

A Developmentally Informed Systematic Review and Meta-Analysis of the Strength of General Psychopathology in Childhood and Adolescence

Considerable support exists for higher-order dimensional conceptualizations of psychopathology in adults. A growing body of work has focused on understanding the structure of general and specific psychopathology in children and adolescents. No prior meta-analysis has examined whether the strength of the general psychopathology factor (p factor)-measured by explained common variance (ECV)-changes from childhood to adolescence. The primary objective of this multilevel meta-analysis was to determine whether general psychopathology strength changes across development (i.e. across ages) in childhood and adolescence. Several databases were searched in November 2021; 65 studies, with 110 effect sizes (ECV), nested within shared data sources, were identified. Included empirical studies used a factor analytic modeling approach that estimated latent factors for child/adolescent internalizing, externalizing, and optionally thought-disordered psychopathology, and a general factor. Studies spanned ages 2-17 years. Across ages, general psychopathology explained over half (~ 56%) of the reliable variance in symptoms of psychopathology. Age-moderation analyses revealed that general factor strength remained stable across ages, suggesting that general psychopathology strength does not significantly change across childhood to adolescence. Even if the structure of psychopathology changes with development, the prominence of general psychopathology across development has important implications for future research and intervention.

Structure of psychopathology in adolescents and its association with high-risk personality traits

The present study examined high-risk personality traits and associations with psychopathology across multiple levels of a hierarchical-dimensional model of psychopathology in a large adolescent, general population sample. Confirmatory factor analyses were run using data from two randomized controlled trials of Australian adolescents (N = 8,654, mean age = 13.01 years, 52% female). A higher-order model - comprised of general psychopathology, fear, distress, alcohol use/harms, and conduct/inattention dimensions - was selected based on model fit, reliability, and replicability. Indirect-effects models were estimated to examine the unique associations between high-risk personality traits (anxiety sensitivity, negative thinking, impulsivity, and sensation seeking) and general and specific dimensions and symptoms of psychopathology. All personality traits were positively associated with general psychopathology. After accounting for general psychopathology, anxiety sensitivity was positively associated with fear; negative thinking was positively associated with distress; impulsivity was positively associated with conduct/inattention; and sensation seeking was positively associated with alcohol use/harms and conduct/inattention, and negatively associated with fear. Several significant associations between personality traits and individual symptoms remained after accounting for general and specific psychopathology. These findings contribute to our understanding of the underlying structure of psychopathology among adolescents and have implications for the development of personality-based prevention and early intervention programs.

Defining the p-factor: an empirical test of five leading theories

BACKGROUND

Despite statistical evidence of a general factor of psychopathology (i.e., p-factor), there is little agreement about what the p-factor represents. Researchers have proposed five theories: dispositional negative emotionality (neuroticism), impulsive responsivity to emotions (impulsivity), thought dysfunction, low cognitive functioning, and impairment. These theories have primarily been inferred from patterns of loadings of diagnoses on p-factors with different sets of diagnoses included in different studies. Researchers who have directly examined these theories of p have examined a subset of the theories in any single sample, limiting the ability to compare the size of their associations with a p-factor.

METHODS

In a sample of adults (N = 1833, Mage = 34.20, 54.4% female, 53.3% white) who completed diagnostic assessments, self-report measures, and cognitive tests, we evaluated statistical p-factor structures across modeling approaches and compared the strength of associations among the p-factor and indicators of each of these five theories.

RESULTS

We found consistent evidence of the p-factor's unidimensionality across one-factor and bifactor models. The p-factor was most strongly and similarly associated with neuroticism (r = .88), impairment (r = .88), and impulsivity (r = .87), χ2(1)s < .15, ps > .70, and less strongly associated with thought dysfunction (r = .78), χ2(1)s > 3.92, ps < .05, and cognitive functioning (r = -.25), χ2(1)s > 189.56, ps < .01.

CONCLUSIONS

We discuss a tripartite definition of p that involves the transaction of impulsive responses to frequent negative emotions leading to impairment that extends and synthesizes previous theories of psychopathology.

Meta-analysis of structural evidence for the Hierarchical Taxonomy of Psychopathology (HiTOP) model

BACKGROUND

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a classification system that seeks to organize psychopathology using quantitative evidence - yet the current model was established by narrative review. This meta-analysis provides a quantitative synthesis of literature on transdiagnostic dimensions of psychopathology to evaluate the validity of the HiTOP framework.

METHODS

Published studies estimating factor-analytic models from diagnostic and statistical manual of mental disorders (DSM) diagnoses were screened. A total of 120,596 participants from 35 studies assessing 23 DSM diagnoses were included in the meta-analytic models. Data were pooled into a meta-analytic correlation matrix using a random effects model. Exploratory factor analyses were conducted using the pooled correlation matrix. A hierarchical structure was estimated by extracting one to five factors representing levels of the HiTOP framework, then calculating congruence coefficients between factors at sequential levels.

RESULTS

Five transdiagnostic dimensions fit the DSM diagnoses well (comparative fit index = 0.92, root mean square error of approximation = 0.07, and standardized root-mean-square residual = 0.03). Most diagnoses had factor loadings >|0.30| on the expected factors, and congruence coefficients between factors indicated a hierarchical structure consistent with the HiTOP framework.

CONCLUSIONS

A model closely resembling the HiTOP framework fit the data well and placement of DSM diagnoses within transdiagnostic dimensions were largely confirmed, supporting it as valid structure for conceptualizing and organizing psychopathology. Results also suggest transdiagnostic research should (1) use traits, narrow symptoms, and dimensional measures of psychopathology instead of DSM diagnoses, (2) assess a broader array of constructs, and (3) increase focus on understudied pathologies.

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.

A systematic review of transdiagnostic risk and protective factors for general and specific psychopathology in young people

A large body of research has emerged over the last decade examining empirical models of general and specific psychopathology, which take into account comorbidity among psychiatric disorders and enable investigation of risk and protective factors that are common across disorders. This systematic review presents findings from studies of empirical models of psychopathology and transdiagnostic risk and protective factors for psychopathology among young people (10-24 years). PsycInfo, Medline and EMBASE were searched from inception to November 2020, and 41 studies were identified that examined at least one risk or protective factor in relation to broad, empirically derived, psychopathology outcomes. Results revealed several biological (executive functioning deficits, earlier pubertal timing, genetic risk for ADHD and schizophrenia, reduced gray matter volume), socio-environmental (stressful life events, maternal depression) and psychological (low effortful control, high neuroticism, negative affectivity) transdiagnostic risk factors for broad psychopathology outcomes, including general psychopathology, internalising and externalising. Methodological complexities are discussed and recommendations for future studies of empirical models of psychopathology are presented. These results contribute to a growing body of support for transdiagnostic approaches to prevention and intervention for psychiatric disorders and highlight several promising avenues for future research.