Screening for depressive symptoms in adolescence: A Rasch analysis of the short-form childhood depression inventory-2 (CDI 2:SR[S])

BACKGROUND: Screening for depressive symptoms during adolescence is of high clinical significance. The shorter 12-item version of the Children's Depression Inventory (CDI 2:SR[S]) was specifically developed for this purpose. Evaluations of the CDI 2:SR[S] psychometrics are limited, however. The purpose of this study was to validate the CDI 2: SR[S] for use as a screening measure using Rasch analysis. METHODS: The CDI 2: SR[S] was administered online to 1513 10-17 year old Western Australian adolescents (635 males, 878 females) from 11 schools. Overall fit, individual item fit, local response dependence, dimensionality, operation of response categories, and differential item functioning (DIF) were examined. RESULTS: The Rasch analysis demonstrated the CDI 2: SR[S] has good reliability. Thresholds for all items were ordered, showing its three response categories functioned as intended. One item (I have to push myself to do schoolwork) showed misfit. No items were locally dependent. Two items (I am sad) and (I have to push myself to do schoolwork) showed DIF for gender. At the same level of depression, females reported being sad more than males, while males pushed themselves more to do schoolwork than did females. Adolescents (14-17 years) reported significantly higher mean depressive symptom scores than early adolescents (10-13 years). LIMITATIONS: Sole reliance on adolescent's self-report and limited data about cultural backgrounds are limitations. CONCLUSIONS: The results support the interval scale measurement properties of the CDI 2: SR[S] and provides educators, clinicians and researchers with a screening measure to assess depressive symptoms in adolescents.