Major depressive disorder (MDD) is a leading cause of global disease burden. Hence, examining the role of risk and protective factors for MDD is an important target in psychological research. Various studies showed that obesity, smoking, and alcohol consumption are related to depressive symptoms. In contrast, physical activity has been found to be a protective factor. The present population-based study tested whether these health-related factors are prospectively associated with incidence of MDD.. To read the full article, log in using your SSSFT NHS OpenAthens details. SSOTP - You can request a copy of this article by replying to this email. Please ensure you are clear which article you are requesting.