Evaluation of the self-reported SDQ in a clinical setting: Do self-reports tell us more than ratings by adult informants?

Abstract
The aim of this study was to evaluate the German self-reported Strengths and Difficulties Questionnaire (SDQ) in a clinical setting. We also investigated whether this additional information gathered directly from older children and adolescents improves the prediction of clinical status when external ratings from their parents and/or teachers are already available. SDQ self-reports were collected from 214 in- and outpatients (81 girls and 133 boys) aged 11 to 17 years who were seen at the department of child and adolescent psychiatry of the University of Göttingen. Results obtained with the self-rated questionnaire were compared with the parent and teacher SDQs, corresponding CBCL/YSR scores, and the clinical diagnostic classification. Finally, the additional diagnostic benefits of the self-reports were examined. The scales of the SDQ self-report proved to be sufficiently homogeneous, and acceptable correlations were found with the equivalent parent and teacher ratings. The self-rated version of the SDQ demonstrated good validity with respect to the differentiation between clinically defined cases and non-cases and in detecting various subcategories of psychiatric disorders within the clinic sample. SDQ self-reports significantly contributed to the prediction of diagnostic status, specifically if only parent or teacher ratings were available. The self-rated version of the SDQ was shown to be a reliable and valid method for the assessment of behavioural problems in children and adolescents. In the absence of adult informant reports from parents and teachers, the diagnostic value of self-ratings was also demonstrated.