Development of health and depressive symptoms among Danish adolescents - Socioeconomic differences and effects of life-style

ABSTRACT
While the existence of social inequality in health in childhood as well as among adults is well es-tablished, research of mechanisms underlying this inequality is still sparse. The study aim was to report on the development of self-rated health and depressive symptoms from age 15 to18 years in a cohort study of Danish adolescents. Methods: The cohort comprised 3,681 individu-als born in 1989, 3058 individuals answered the baseline questionnaire in 2004, and 2400 re-sponded to a follow-up questionnaire in 2007, with 2181 individuals participating in both rounds (59% of the original cohort). Social background information of the participants was derived from a national register. For the analysis two vari- ables indicating change in the two health indi- cators was computed by subtracting the 2007 levels of the variables from the levels experi- enced in 2004. Results: After 3 years, mean self-rated health (SRH) deteriorated slightly in adolescents (-0.24; 95% CI = -0.28 to -0.19) across all socioeconomic status (SES) groups and depressive symptoms increased (0.64; 95% CI = 0.52 to 0.75). High household income was protective for decrease in SRH (0.62; 0.43 - 0.91). Negative life-style changes were associated with poorer SRH and more depressive symptoms. Conclusions: Self-rated health and depressive symptoms changed to the worse among Danish adolescents from age 15 to 18 years. Negative changes in several lifestyle factors were found to accompany the deterioration of health. This result stresses the intrinsic relationship be- tween lifestyle changes and health and the pos- sible positive effect of maintaining and enhanc- ing positive lifestyle factors.