Depression and anxiety (DA) are important dimensions of mental health (MH) with a significant and growing contribution to the global burden of disease. In resource-poor contexts, DA have also been widely recognized as having important implications for demographic events and behaviors such as mortality, migration and divorce, individual productivity, individual/family-level well-being, and overall economic development. Mature adults, defined here as adults aged 45+, are a rapidly-growing subpopulation with key social and economic roles for whom DA and its implications are poorly understood. But there is a lack of longitudinal data on older individuals in SSA that allow us to study the life-course implications of DA and poor MH. To help fill this gap in our knowledge, the specific aims of this project include: (1) Collect new MLSFH data on DA, mortality, marriage and migration in 2016 that, in combination with already existing 2 rounds (2012–13) MLSFH data, will establish a cohort of 1,200+ mature adults aged 45+ for whom this project will obtain the first-ever SSA longitudinal population-based data on depression, anxiety and related key life-course outcomes. (2) Investigate the effects of DA on mortality, migration and demographic behaviors such as divorce/remarriage among mature adults, including the relationship between DA and mortality, the extent to which DA affects family outcomes, such as separation, divorce, remarriage, and analyses of whether migration is an effective coping strategy for mature adults affected by DA. (3) Investigate the patterns, correlates and determinants of DA among mature adults and possible differentials by age, sex, physical health status, socioeconomic status, and family structure.