Does the Strengths and Difficulties Questionnaire – self report yield invariant measurements across different nations? Data from the International Child Mental Health Study Group.


Aims. This study evaluated the measurement invariance of the strengths and difficulties questionnaire (SDQ) self-report among adolescents from seven different nations. Methods. Data for 2367 adolescents, aged 13-18 years, from India, Indonesia, Nigeria, Serbia, Turkey, Bulgaria and Croatia were available for a series of factor analyses. Results. The five-factor model including original SDQ scales emotional symptoms, conduct problems, hyperactivity-inattention problems, peer problems and prosocial behaviour generated inadequate fit degree in all countries. A bifactor model with three factors (i.e., externalising, internalising and prosocial) and one general problem factor yielded adequate degree of fit in India, Nigeria, Turkey and Croatia. The prosocial behaviour, emotional symptoms and conduct problems factor were found to be common for all nations. However, originally proposed items loaded saliently on other factors besides the proposed ones or only some of them corresponded to proposed factors in all seven countries. Conclusions. Due to the lack of a common acceptable model across all countries, namely the same numbers of factors (i.e., dimensional invariance), it was not possible to perform the metric and scalar invariance test, what indicates that the SDQ self-report models tested lack appropriate measurement invariance across adolescents from these seven nations and it needs to be revised for cross-country comparisons.