The objective of this article is to demonstrate, from the hermeneutics of the Political Charter of 1988, the existence of the fundamental social right to mental health. In this sense, the path taken in the construction of the legal argumentation will present historical and institutional aspects of the Brazilian public health field, in accordance with the health debates and the incorporation of the Unified Health System (SUS). With the advent of the Law on Psychiatric Reform (Law No. 10,216/01), a legal norm of an infra-constitutional nature, the National Mental Health Policy was established, which presented, in a broad way, care in the mental field and the political reinforcement of constitutional norms related to fundamental civil and social rights for all citizens, including people in psychological distress. Finally, another legal device in the country's legal system, with the status of Constitutional Amendment, which also ratifies the existence of the category social right to mental health, is the International Convention on the Rights of Persons with Disabilities (2006), which presented numerous protective amendments to promote the emancipation of persons with disabilities, including mental, for political participation.