Background and Objective: Children and adolescents need environments and systems that prevent mental health and developmental disorder problems, comprehensive primary care that is able to respond early to their needs, and methods of compassionate mental health care when other interventions fail. Methods: This paper provides a narrative review of the history of child and adolescent mental health practices and prevailing themes that connect mental health with the wider field of non-communicable disease (NCD) prevention and treatment. Key Content and Findings: Inclusion of mental health as part of the World Health Organization NCD agenda has raised global awareness of mental health issues, including the need for continued de-stigmatization, clinician training, and access to essential medicines. The policy arena for mental health is complex, and we reflect on missed opportunities for meaningful integration of mental health within holistic life-course oriented healthcare delivery systems. We explore bidirectional links between physical and mental health, and the impact of social determinants and early childhood experiences on morbidity and mortality. We examine the prevention of mental health problems, noting risk factors shared with other NCDs, and reflect on mental health treatment-with and without the use of medicines-underlining the importance of universal health coverage (UHC) for children and adolescents' mental health and wellbeing. Conclusions: Considerable work is needed to better integrate mental health and other NCD related care into front-line primary health care delivery and to include a true life-course approach to NCD prevention and treatment for children and youth.