This study aimed to examine the psychometric properties of the School Depression Screening Scale (SDSS) and its relationship with the depression subscale of the DASS-21 (DASS-D) among secondary school students in Vietnam. The study sample consisted of 2,511 students aged 11-18 from 3 major regions of Vietnam (Hanoi, Hue, Ho Chi Minh city). Analyses included internal consistency reliability, item analysis, confirmatory factor analysis, measurement invariance testing across demographic groups, and comparisons with the DASS-D. The results indicated that the SDSS demonstrated good reliability, a coherent factor structure, and measurement invariance across gender, educational levels, and regions. The SDSS showed a strong convergent correlation with the DASS-D; however, the two scales did not completely overlap structurally, instead reflecting different aspects of depressive experiences among students. The SDSS emphasizes negative self evaluation, loneliness, and perceived social disconnection within the school context, whereas the DASS-D reflects core depressive symptoms. The findings suggest that the SDSS is an effective instrument for screening school-related depression, particularly when used in combination with the DASS-D to support the early identification of students at risk of depression. This study also proposes T-score conversion table for DASS-D and SDSS for screening school depression among Vietnamese secondary school students.
Ta et al. (Sat,) studied this question.