Serious depression in parents and caregivers can affect far more than the adults who are ill. It also influences the well-being of the children in their care. Because chronic and severe maternal depression has potentially far-reaching harmful effects on families and children, its widespread occurrence can undermine the future prosperity and well-being of society as a whole. When children grow up in an environment of mental illness, the development of their brains may be seriously weakened, with implications for their ability to learn as well as for their own later physical and mental health. When interventions are not available to ensure mothers’ well-being and children’s healthy development, the missed opportunities can be substantial.