The Factor Structure and Measurement Invariance of Parent-Report Strengths and Difficulties Questionnaire During a Public Health Crisis.

The parent-report Strengths and Difficulties Questionnaire (SDQ) is a widely used child and adolescent mental health screening tool. However, challenging environments, such as public health crises, may influence the construct validity of measures. To assess this, we examine SDQ measurement invariance, internal consistency, convergent and discriminant validity, composite, test-retest, and interrater reliability across parents from the United Kingdom (n = 9,001) and Japan (n = 365). We replicate the five-factor structure, which held across children's age, gender, and between parent- and adolescent-report. We provide new evidence of SDQ invariance for special educational needs (SEN), across 6- and 1-month reporting windows, over different periods of restrictions, and between English (UK) and Japanese versions. Taken together, our findings suggest that parents interpreted the SDQ items in similar ways to pre-pandemic norms. Yet relatively low reliability of the conduct and peer relationship subscales, in particular, indicates a need for caution and scale revisions, especially when used for screening and diagnosis.