Validation of Children's Depression Scale in the Basque-speaking population

The aim of this study was to validate the Basque version of the CDS (Children's Depression Scale, Lang & Tisher, 1978), one of the most widely used questionnaires for the assessment of childhood depression, which has already been proved to be a valid and reliable tool in different cultures. The questionnaire was administered to a community sample of 886 participants (432 males and 454 females) aged between 8 and 16. A two-factor solution was obtained (Depressive dimension and Positive Dimension), which accounted for 29.86 % of the variance. Reliability with regard to internal consistency level and long-term stability was good (alpha = .95 and .79; and R = .73 and .59 for Depressive and Positive dimensions, respectively). Analysis of Differential Item Functioning with respect to age and gender showed that 91% and 88% of the items, respectively, did not present DIF. External validity evidence for the questionnaire was also obtained. We consider that the present work offers researchers and professionals interested in this area of study a valid and reliable tool for assessing depressive symptoms in Basque-speaking children and adolescents.