A replication and extension of bifactor modelling of perseverative thought in an at-risk community sample: Exploring sex differences in the structure of PT

Background Perseverative thought (PT) is a transdiagnostic construct associated with internalizing disorders. Bifactor models have shown that PT can be split into a general PT factor and lower-order factors for specific forms of PT, such as rumination and worry. No bifactor study to date has investigated if the structure of PT differs across sexes. Methods The study consisted of 280 individuals recruited for a larger study targeting risk factors for suicidal ideation and behaviours. Participants completed a diagnostic interview and self-report questionnaires. Results A two-factor model of PT fit best in males, whereas a bifactor model fit best in females. In a structural equation model, worry was associated with generalized anxiety disorder diagnoses in females, but not males. Rumination was associated with depressive disorder diagnoses in females, but not males. Conclusions The present study contributes to a growing literature on PT; we found that dimensionality of PT varied by sex. We also found that relations between PT factors and generalized anxiety disorder differed by sex. Sex differences in the internalizing spectrum and related risk factors need to be considered when examining the structure and function of risk factors.