Objective: The (SDQ) is a short questionnaire which addresses positive and negative behavioural attributes of children or adolescents. Being rated by parents or teachers, or as an equivalent self-report version, the 25 SDQ items were designed to include both strengths and difficulties. Although several reports have demonstrated the validity of the German SDQ, normative data have not yet been established.
Methods: In a nationwide representative field study, parent ratings were completed for 930 children and adolescents aged between 6 and 16 years. Following verification of the scale structure by factor analysis, the observed distributions of scores were used to define normal, borderline, and abnormal score ranges. Possible effects of gender, age, and social class were also investigated.
Results: Factor analysis yielded an exact replication of the original scales. Several associations with gender, age, and social status attained statistical significance, but cut-off scores for the five subscales remained stable in different subgroups. Age- and sex-specific bandings for the total problem score reflected small differences between homogeneous subgroups.
Conclusions: After replication and confirming the original scale factors, the availability of normative data further enhances the diagnostic value of the SDQ and facilitates future validation studies. Present evidence suggests that the SDQ may serve as a useful and economical screening measure, and in many other clinical and research settings.