In the member countries of the Organisation for Economic Co-operation and Development (OECD), about 13% of children and adolescents have at least one mental disorder, i.e. a condition that affects mental health and can take many different forms and expressions. Although the lack of data on the French situation makes it difficult to estimate the numbers involved, it can nevertheless be estimated that around 1.6 million children and adolescents suffer from a mental disorder. As in other OECD countries, the Covid-19 epidemic has resulted in a significant increase in mental health problems in children aged 10 and over and in adolescents. The report published today by the Court of Accounts aims to quantify the need for child and adolescent mental healthcare by assessing the prevalence of disorders and the available provision, and to analyse the organisation of the supply of care, its distribution over the territory and its cost to public finances.