5. Conclusion
This study demonstrated via confirmatory factor analysis that
the correlated three factor structure of the 30-item USDI was
replicated with the addition of the second order ‘total score’ factor
—demonstrating construct validity. Utilising a larger and more
diverse sample than the original research, the three factors of
lethargy, cognitive–emotional and academic motivation, leading to
a second order ‘total score’ factor was found to be the best fit for
the data. Good internal consistency, temporal stability, as well as
sound convergent and discriminant validity of the USDI was also
demonstrated. Further, the cut-off scores outlined in this study
provide descriptive severity categories to aid interpretation of
USDI scores in individual applications. It is concluded that the
USDI is a valid and reliable tool to aid in the assessment of
depressive symptoms among university students.