Unravelling the relation between physical activity,self-esteem and depressive symptoms among early and late adolescents: A mediation analysis

PurposeDepression is a serious public health issue among adolescents; however, few studies have examined the role of protective factors, such as engagement in physical activity, on depressive symptoms. Preliminary evidence using community samples of mainly adolescent girls suggests that self-esteem may influence the benefits of physical activity on depressive symptoms. Thus, the objective of this study was to test the hypothesis that the inverse relation between physical activity and depressive symptoms would be mediated by self-esteem in both early and late adolescent boys and girls.MethodsSecondary data analysis was conducted using self-reported measures of physical activity, self-esteem, depressive symptoms, and socio-demographic information completed by a sample of girls (n = 2109) and boys (n = 2095) during early (M_age = 14.7) and late (M_age = 16.2) adolescence selected from the National Longitudinal Study of Adolescent Health. Using the method suggested by Baron and Kenny (1986), mediation was tested separately for boys and girls during early and late adolescence.ResultsDuring early adolescence, self-esteem fully mediated the association between physical activity and depressive symptoms for adolescent boys only. Full mediation was obtained for both boys and girls during late adolescence.ConclusionsIn early and late adolescent boys, and only late adolescent girls, associations between physical activity and depressive symptoms were no longer significant once self-esteem was statistically controlled for. The study has important implications for depression prevention initiatives including the inclusion of physical activity components that are effectively structured to reliably enhance self-esteem, especially among early adolescents.