An international initiative launched in 2018 to improve the consistency and quality of data on adolescent health and well-being worldwide, addressing longstanding gaps in how the needs of young people aged 10–19 are understood and monitored. Developed in collaboration with key UN partners, it establishes a standardized framework of indicators across multiple domains, including health outcomes, behaviours, and social determinants. Its relevance to child and adolescent mental health lies in its holistic approach, which embeds mental health within broader measures of well-being rather than treating it in isolation. By incorporating indicators related to emotional well-being, risk exposure, and environmental influences, GAMA enables more reliable tracking of mental health needs and highlights the complex factors shaping outcomes during adolescence—a critical developmental period when many mental health conditions first emerge. This integrated, data-driven approach supports more effective policy, prevention, and service planning, ultimately strengthening global efforts to promote mental health and well-being among children and adolescents