"The phrase “Contraindre est thérapeutique”— constraining is therapeutic— underpins theprinciple of numerous interventions within the field of mental health in France, ranging from traditional psychiatric units to the courthouse to violence management and prevention of dangerousness. The treatment of violence in “difficult and violent adolescents” provides a paradigmatic and revealing example of this tendency.The aim of this article is to understand how the clinical category— contenir, or “to contain”— was formed and is used. The perspective taken is that of the political anthropology of mental health and the article combines a genealogical approach of the notion with a multisite ethnographical study in three facilities for adolescent care'. This study will show how “psychological holding ” is used to justify “physical constraint ” in the treatment of adolescent crisis and violence. Furthermore, we will see how this “dirty work”, delegated to front) line professionals educators, social workers,nurses', is used within a moral economy of suffering that promotes care and control measuresin a population largely from immigrant backgrounds, (udged to be both potentially vulnerableand dangerous"