In the field of public health, mental health has had a great deal of relevance. This concept has been used extensively in the professional, academic, and political fields. Despite that, the different definitions of mental health face significant epistemological and practical problems. These difficulties are encountered by those who try to specify the meaning of "mental", the relationship between "health" and "mental", and, consequently, how research and intervention actions are to be carried out in the field of mental health. In practice, the orientation of actions and research involving mental health is not based on “universal” definitions in the field of public health. It is rather based on conceptions constructed from different approaches to the health-disease issue. This paper discusses the conceptions of mental health that have been configured from the biomedical, behavioral, and socio-economic approaches, the notions of "mind" underlying these conceptions, and their implications for intervention in the field of public health.