The aim of this article is to offer some thoughts about the place of the pharmacological prescription within the framework of the institutional treatment of children and adolescents who present severe psychological disorders. Far from being a simply technical approach, prescribing medication to an adolescent within an institution corresponds to the construction of a transitional space which is the fruit of the encounter between the adolescent and the staff. The action of the psychotropic drugs must be inscribed in the overall psychical economy of the subject, taking into account the relationship between medication and the question of dependence and the inevitable issues of mastery and control that this engenders in adolescence, which are amplified by the institutional setting. Lastly, it is important to emphasize that this problematic must not be seen as confined to the specific institution which receives the adolescent, but applies more widely to the different institutions and referents which deal with the adolescent in the perspective of a multi-focus treatment among institutions and a longitudinal and parallel conception of treatment.