Validation and Heritability of the Hierarchical Taxonomy of Psychopathology

The Hierarchical Taxonomy of Psychopathology (HiTOP) model is an empirically based dimensional alternative to current consensus based diagnostic classification systems. The model was developed by synthesizing the findings of decades of empirical studies, but it has never been comprehensively validated using a confirmatory, bottom-up modeling approach within a single sample. We assessed 108 psychopathology phenotypes, including 37 novel components, in 1,394 twins (542 monozygotic pairs, 155 dizygotic pairs) with diverse mental health histories to characterize the hierarchical dimensional structure of psychopathology and quantify its genetic and environmental influences. Confirmatory factor analyses largely replicated the dimensions at the lower tiers of the model. Some dimensions at higher levels of the final 6-tiered model showed evidence of multidimensionality and subthreshold convergent validity, suggesting they may not be cohesive unitary constructs. Our findings provide tentative validation for the HiTOP model while identifying novel psychiatric phenotypes and heritability estimates to guide subsequent biological studies.