Validation of the Depression Anxiety Stress Scale-21 (DASS-21) in a non-clinical sample of South African working adults

This study investigated the psychometric properties of the Depression Anxiety Stress Scale-21 (DASS-21) in a non-clinical sample of working people. Working South African persons (N = 269; females = 62%; mean age = 33, SD = 11.5) completed the DASS-21, as well as the Center for Epidemiologic Studies Depression Scale-Revised (CESD-R) and the Generalized Anxiety Disorder Scale-7 (GAD-7). Results following Confirmatory Factor Analysis and correlational analysis yielded a three-factor structure (depression, anxiety, and stress) for the DASS-21. The evidence for discriminant and convergent validity was strong. Additionally, we found good reliabilities for the overall scale as well as the subscales. The DASS-21 appears a valid and reliable instrument for measuring depression, anxiety, and stress in the workplace. Future studies should investigate differential item functioning and equivalence of items among South African working populations.