Strengths and Difficulties Questionnaire (SDQ)

Abstract

This study examines whether the German translation of the Strengths and Difficulties Questionnaire (SDQ) is a reliable and valid screening instrument and whether it is as effective a tool for clinical diagnostics and scientific applications as the CBCL / TRF and 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. We examined 543 children and adolescents (147 girls and 396 boys) with ages ranging from 5 to 17 years and correlated the results of the parent and teacher SDQ as well as the CBCL / TRF with clinical diagnoses. Furthermore, the adequacy of the scale structure of the SDQ was tested using confirmatory and exploratory factor analyses. Additionally, a sample from 10 European countries with 1,459 children with ADHD (aged 6–18 years) will be analyzed. It was demonstrated that the scales of the parent and teacher versions were sufficiently homogeneous (.72 - .83). Correlations between SDQ scales and corresponding CBCL / TRF scales showed a high degree of congruence, while an exact replication of the original SDQ scale structure could also be achieved. Parent and teacher versions of both questionnaires presented with good validity, not only with regard to the discrimination between child psychiatric patients and a representative community sample, but also in the identification of different categories of disorders within the clinical sample. The mean total difficulties and SDQ subscale scores of the ADORE sample clearly differed from UK normative data. Younger children were more impaired on different SDQ scales than older children, and girls were more emotionally affected than boys. Differences between countries were found for each SDQ scale, but the investiga! tor type had no significant effect. Correlation coefficients between S DQ scales and other scales used in ADORE ranged from low (r<0.30) to high (r>0.50). The parent and teacher and self-rated version of the SDQ proved to be valid and helpful questionnaires for use in the framework of a multi-dimensional behavioural assessment, and appear to be well-suited for screening purposes, longitudinal monitoring of therapeutic effects, and scientific research purposes. In contrast to investigator type, different cultures had a significant effect on SDQ scores. Correlations with other scales used in the ADORE study underline both separate domains and meaningful associations.