A short form of the ambiguous scenarios test for depression in adolescents: development and validation

The Ambiguous Scenarios Test for Depression in Adolescents (AST-DA) is a 20-item measure of depressive interpretation bias. It has good face and construct validity and discriminates between clinical and non-clinical samples. However, a shorter measure would reduce burden on young people and make the instrument more useful in clinical settings. The aim of this study was to develop a valid and reliable short-form of the AST-DA. Adolescents recruited from the community (N = 206) completed the 20 item measure. Based on theoretical considerations and statistical analyses we selected 9 items to create a short form of the AST. This 9-item version was tested on a clinical sample of 69 young people referred for depression to a child and adolescent mental health service in the UK. The validity and internal reliability of the Short-AST-DA were confirmed. These data suggest that the Short-AST-DA is a robust measure of depressive interpretation bias in young people. Future work should investigate the measure?s test-retest reliability, sensitivity to change and convergent validity.