Abstract
Recent years have seen a shift toward alternative nosologies of psychopathology, which frequently include a dimension of externalizing psychopathology. The Hierarchical Taxonomy of Psychopathology is one such framework. Research using data from the Adolescent Brain and Cognitive Development (ABCD) Study has identified a broad-based externalizing dimension, but no research to date has sought to empirically identify finer-grained externalizing subdimensions despite the research benefits associated with the use of homogenous dimensions. Furthermore, no work to date has examined whether externalizing dimensions are invariant over time. Thus, the current study had two primary aims: Aim 1-identify the hierarchical structure of externalizing psychopathology and examine evidence of discriminant validity of identified dimensions and Aim 2-assess the longitudinal measurement invariance of a broad externalizing dimension in the ABCD Study, as well as specific underlying subdimensions. The results for Aim 1 analyses identified a coherent factor structure comprising a broad externalizing dimension and three subdimensions (conduct problems, irritability, and neurodevelopmental problems), and these factors showed important similarities and differences in relation to external correlates. Aim 2 analyses showed that strong invariance was supported for the conduct problems and irritability dimensions, while partial strong invariance was supported for broad externalizing and neurodevelopmental problems. Quantification of measurement (non)invariance revealed small effect sizes. The results highlight important directions for future research on externalizing psychopathology in the ABCD Study. (PsycInfo Database Record (c) 2025 APA, all rights reserved).