Brief and Valid? Testing the SDQ for Measuring General Psychopathology in Children.

Background: The general psychopathology factor (p factor) is central to understanding the shared variance across mental disorders, offering a dimensional alternative to traditional diagnostic models. The early identification of this factor in childhood is key for improving prevention and intervention strategies. This study evaluated the Strengths and Difficulties Questionnaire (SDQ) as a brief measure to assess p factor in children. Methods: A community sample of 284 children, ages 6 to 12, was assessed using parent-reported SDQ and the Child Behavior Checklist (CBCL). Confirmatory Factor Analyses compared two models of psychopathology: a higher-order model and a first-order bifactor model. Results: Results showed that the bifactor model provided a better fit for both instruments, with the SDQ showing particularly strong fit indices. Moreover, SDQ-derived p factor scores were strongly correlated with key CBCL scales, particularly attention and externalizing problems, supporting its concurrent validity. Conclusions: These findings suggest that the SDQ, due to its brevity and psychometric robustness, is a valid alternative to the CBCL for assessing general psychopathology in children.