A thorough investigation of the bifactor model of psychopathology in a representative birth cohort: Testing internal and predictive validity to inform models of comorbidity.

This study used symptom dimensions reflecting DSM-V internalizing, externalizing, eating disorders, and substance use (SU) and related problems to thoroughly investigate the structure of psychopathology in mid-adolescence (15 and 17 years, N = 1,515, 52% female). Compared to other hierarchical configurations (unidimensional, correlated factors, or higher-order model), a bifactor model of psychopathology wherein all first-order symptom dimensions loaded onto a second-order general psychopathology factor (P factor) and one of three, second-order specific internalizing, externalizing, or SU factors, best captured the structure of the psychopathology in mid-adolescence. This bifactor model was then used to predict several distinct mental health disorders and alcohol use disorder (AUD) at 20 years, via a structural equation model (SEM). The P factor (bifactor model) was associated with all but one outcome (suicidal ideation without an attempt), at 20 years. Controlling for the P factor, there were no additional, positive, temporal cross-associations (i.e., between mental health (mid-adolescence) and AUD at 20 years, or between SU (mid-adolescence) and mental health problems at 20 years). These results are bolstered by findings from a well-fitting correlated factors model. Namely, when mid-adolescent psychopathology was modeled using an adjusted correlated factors model, associations with outcomes at 20 years were largely masked, with no significant partial, temporal cross-associations. Thus, collectively, findings indicate that comorbidity between SU and mental health in youth may be largely attributable to an underlying liability to experience both problems (i.e., P factor). Ultimately, results support targeting the common liability to psychopathology in the prevention of later mental health problems and AUD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).