Reliability of the Beck Depression Inventory and the Self-Rating Anxiety Scale in a sample of South African adolescents.

Objective - This study aimed to assess the reliability of the Beck Depression Inventory (BDI) and the Self-Rating Anxiety Scale for epidemiological investigations of adolescents' symptoms. Method - Self-report questionnaires were administered on two occasions to 104 students in four private high schools in Cape Town, South Africa. Test-retest reliability was assessed using Cohen's kappa and observed agreement. Internal consistency of each scale was assessed using Cronbach's alpha. Resuls - All items of the BDI and all but four of the Self-Rating Anxiety Scale had at least fair Kappa scores. The remaining four items of the Self-Rating Anxiety Scale had reasonable observed agreement and reflect more transient states that are likely to change between administrations. Conclusions - The results give encouraging indication that these instruments may be reliable in developing contexts. However, the study is limited by a sample that is small and not sufficiently representative of the broader South African population. Future studies should include larger and more representative samples, in order to explore item bias in different race and gender subgroups. Validity also needs investigation.