Strengths and Difficulties Questionnaire: Psychometric Properties and Normative Data for Spanish 5- to 17-Year-Olds.

The Strengths and Difficulties Questionnaire (SDQ) has been extensively used to measure common forms of psychopathology among children and adolescents. However, its psychometric properties vary across countries and several controversial issues warrant further investigation. This study aimed to evaluate whether the Spanish version of the SDQ is a reliable and valid tool for assessing emotional and behavioral problems in a sample of 6,775 students aged 5 to 17 years, as rated by parents, teachers, and youth. We examined the internal consistency of the questionnaire, its factor structure, and measurement invariance across child's gender and age. Criterion validity was tested against the Child Behavior Checklist (CBCL), Teacher's Report Form (TRF), and Youth Self-Report (YSR), and we measured the ability of the SDQ to identify children with specific psychiatric disorders. Finally, we provide, for the first time, Spanish normative data for children aged 5 to 10 and 11 to 17 years, according to gender and each informant. Our results revealed acceptable reliability estimates for all SDQ subscales. Confirmatory factor analysis supported the original five-factor model and full measurement invariance was found. Furthermore, SDQ scores showed a moderate to strong correlation with those on the equivalent CBCL/TRF/YSR scales, and were effective in discriminating individuals with and without clinical diagnoses.