Factor structure of the Zung Self-rating Depression Scale in first-year university students in Japan.

The Zung-Self-rating Depression Scale (SDS) was distributed to 28,588 first-year university students. Factor analysis using PROMAX rotation revealed three factors interpretable as affective, cognitive, and somatic symptoms. The confirmatory factor analysis showed a goodness-of-fit index of 0.976 and an adjusted goodness-of-fit index of 0.967. The two sexes exhibited virtually the same factor structure. The result suggests that studies with this scale should use these three subscales rather than a total score.