Use of the Strengths and Difficulties Questionnaire to assess the mental health needs of children and adolescents with intellectual disabilities.

Background Over the last decade increased attention has been paid to identifying and responding to the mental health needs of children and adolescents with intellectual disabilities. There is, however, little information available on the use of self-report scales by young people with intellectual disabilities. This study sought to determine the reliability and validity of the child, carer and teacher versions of the extended Strength and Difficulties Questionnaire (SDQ) when used with this population. Method Secondary analysis was undertaken of a nationally representative survey of the mental health of 4,172 children between 11 and 15 years of age in Great Britain. Data were extracted on an operationally defined sub-sample of 98 children with intellectual disabilities. Results All scales on the SDQ proved to be internally consistent. Acceptable levels of validity were found by examining: (1) correspondence between parallel child, carer and teacher versions of the SDQ; (2) association between SDQ scores and ICD-10 diagnoses. Conclusion The extended SDQ appears to provide a simple robust measure of the mental health needs of children and adolescents with intellectual disabilities