Psychometric properties of the strengths and difficulties questionnaire

Objective: To describe the psychometric properties of the Strengths and Dif ficulties Questionnaire (SDQ), a brief measure of the prosocial behavior an d psychopathology of 3-16-year-olds that can be completed by parents, teach ers, or youths. Method: A nationwide epidemiological sample of 10,438 Briti sh 5-15-year-olds obtained SDQs from 96% of parents, 70% of teachers, and 9 1% of 11-15-year-olds. Blind to the SDQ findings, all subjects were also as signed DSM-IV diagnoses based on a clinical review of detailed interview me asures. Results: The predicted five-factor structure (emotional, conduct, h yperactivity-inattention, peer, prosocial) was confirmed. Internalizing and externalizing scales were relatively "uncontaminated" by one another. Reli ability was generally satisfactory, whether judged by internal consistency (mean Cronbach alpha: .73), cross-informant correlation (mean: 0.34), or re test stability after 4 to 6 months (mean: 0.62). SDQ scores above the 90th percentile predicted a substantially raised probability of independently di agnosed psychiatric disorders (mean odds ratio: 15.7 for parent scales, 15. 2 for teacher scales, 6.2 for youth scales). Conclusion: The reliability an d validity of the SDQ make It a useful brief measure of the adjustment and psychopathology of children and adolescents.