Helping Adolescents Thrive (HAT) is a joint WHO-UNICEF initiative to strengthen programming and policy responses for adolescents, to promote positive mental health, prevent mental health conditions, and prevent self-harm and other risk behaviours. The vision of HAT is a world in which all adolescents, their caregivers, civil society and communities unite with governments to protect and promote adolescent mental health. This means taking action routinely to implement and monitor evidence-informed and human rights-based strategies for improving mental health, and to prevent and reduce mental health and substance use conditions in adolescents in order to improve lifelong well-being