A cross-sectional study examining the reliability and invariance of the Depression, Anxiety, and Stress Scale-21 (DASS-21) across ten countries/regions.

Background: The Depression, Anxiety, and Stress Scale-21 (DASS-21) is widely used to assess psychological symptoms among university students. However, its factor structure remains inconsistent, and few studies have employed advanced modeling approaches such as exploratory structural equation modeling (ESEM), particularly in cross-cultural contexts. Objectives: The present study evaluated the factor structure of the DASS-21 by comparing five models: unidimensional, oblique three-factor, bifactor, three-factor ESEM, and bifactor ESEM. For the best-fitting model, internal consistency and measurement invariance across cultural, linguistic, and demographic groups were further examined. Methods: Using secondary data from an international mental health project, this cross-sectional study analyzed responses from 12,059 university students ( Results: The three-factor ESEM model showed the best fit across the ten countries/regions with acceptable fit indices, satisfactory internal consistency (McDonald's Conclusions: These findings support the DASS-21's robust internal structure and reliability across diverse student populations, while emphasizing caution in cross-cultural comparisons.