INTRODUCTION: The Strengths and Difficulties Ques-tion-naire (SDQ) is a brief well-validated psychometric instrument for assessment of developmental, behavioural and emo-tional problems in children and adolescents. Versions of the questionnaire covering the 2-17-year age range are an-swered by parents and by pedagogues or teachers. Also, a self-report version can be used from the age of 11 years. The SDQ is well-accepted by informants and is increasingly preferred both internationally and in Denmark for research and evaluation purposes. The questionnaire is also well-suited for clinical use, especially in the primary sector. However, no comprehensive set of Danish norms has been available before this study.

METHODS: Data from an extensive survey in a Danish municipality was used to generate national norms for SDQ scores. These norms were compared with British and Nordic population data.

RESULTS: Across informants, threshold values show some variation with age and often differ between sexes. Therefore, norms are provided both with and without gender stratification. Similarities as well as differences were found between the Danish norms and materials from other countries. The differences may, to some extent, be attributable to methodological issues.

CONCLUSION: We expect that the availability of Danish SDQ norms will further stimulate the use of the instrument.

FUNDING: TrygFonden provided financial support for the development of Danish SDQ norms.

TRIAL REGISTRATION: not relevant.