Factor structure of the Strengths and Difficulties Questionnaire (SDQ) in preschool aged children

Factor analytic studies assessing the construct validity of the Strengths and Difficulties Questionnaire (SDQ) have shown mixed findings in the past. Given the thirteen year age range of the questionnaire and all the developmental changes children undergo during that time, an accurate assessment of the questionnaire's construct validity across age is crucial. Research on the developmental trajectories of pathology indicate that internalizing and externalizing psychosocial maladaptation as well as normative development is heterogeneous during the preschool years. An especially important time for the identification, prevention and intervention of psychosocial maladaptation. In the present study, the construct validity of the SDQ is assessed, by comparing the three models that have been hypothesized to represent the latent factors of the SDQ. Since development during the preschool years is especially capricious, age effects are further inspected in the model that shows the best fit. The sample under study is a fairly large, representative community sample of 851 Icelandic children, four to six years old, attending preschool. The original five-factor structure of the SDQ showed a good fit on the selected indices, and a better fit of the two proposed models. The five-factor model also showed good fit on the fit indices in a multigroup CFA across age, showing desirable psychometric properties pertaining to measurement invariance, but indicated population heterogeneity through different means on the latent variables. Together, these results support that the SDQ has similar psychometric properties for preschoolers as for older children, nevertheless narrower age gaps might be needed for clinical cut-off scores due to population heterogeneity at least for the youngest subjects