Abstract
BACKGROUND: This study examined (1) the factor structure of a depressive symptoms scale (DSS), (2) the sex and longitudinal invariance of the DSS, and (3) the predictive validity of the DSS scale during adolescence in terms of predicting depression and anxiety symptoms in early adulthood. METHODS: Data were drawn from the Nicotine Dependence in Teens (NDIT) study, an ongoing prospective cohort study of 1,293 adolescents. RESULTS: The analytical sample included 527 participants who provided complete data or had minimal missing data over follow-up. Confirmatory factor analysis revealed that an intercorrelated three-factor model with somatic, depressive, and anxiety factors provided the best fit. Further, this model was invariant across sex and time. Finally, DSS scores at Time 3 correlated significantly with depressive and anxiety symptoms measured at Time 4. CONCLUSIONS: Results suggest that the DSS is multidimensional and that it is a suitable instrument to examine sex differences in somatic, depressive, and anxiety symptoms, as well as changes in these symptoms over time in adolescents. In addition, it could be used to identify individuals at-risk of psychopathology during early adulthood.