In recent years, prominent experts have urged changes to help end longstanding disparities between physical and mental health care, and to foster wellness. This report builds on that prior work. Child Trends argues that the distinction between physical and mental health is both artificial and harmful, and make a case for re-balancing attention to include wellness in addition to illness. It is important to identify and address the needs of children at risk, while also improving the mental wellness supports and services available to all children and youth. Therefore, Child Trends considered the evidence for interventions, both prevention- and promotion-oriented, that can improve mental wellness at the multiple levels of individual, family, school, and community.