<p>This study sought to build knowledge on adolescents’ optimism and social connectedness as potential pathways linking mother- and father-child relationships in middle childhood to young adults’ depressive symptoms. Using the low-income Future of Families and Child Wellbeing cohort (N = 4741), we tested hypotheses that optimism and social connectedness at age 15 will partially explain the associations among mothers’ and fathers’ closeness to children and harsh parenting at age 9 and depressive symptoms at age 22. Results did not support hypotheses that young adults will report fewer depressive symptoms when mothers and fathers have closer relationships with their offspring and engage in less harsh parenting during middle childhood. However, sex differences emerged, with mothers’ harsh parenting at age 9 having a significantly stronger direct association with girls’ depressive symptoms at 22 than on boys depressive symptoms. There were significant indirect effects of mother-child closeness and father-child closeness at age 9 on depressive symptoms at 22. Specifically, higher levels of mother and father closeness to 9-year-olds were associated with 15-year-olds’ reports of greater social connectedness, which in turn was related to fewer depressive symptoms at age 22. In addition, social connectedness was a significantly stronger mediator of the association between mothers’ closeness and depressive symptoms among young adult girls than young adult boys. This article discusses implications of the study results for programs that seek to help parents to form and maintain close and warm relationships with children that may help to reduce the risk of mental health problems during young adulthood.</p>