In this article, the author shows how the concept of subjectivation grew out of clinical work on psychotic states in adolescence. These are related to a melancholic core that is sometimes difficult to discern beneath the drive conflicts of puberty. Using a clinical case of adolescent-onset psychosis, the problem of the fundamental relation between psychosis, temporality and melancholy is restated in a way that can account for “ borderline ”-looking symptomotologies, within a post-Freudian theoretical framework and with reference to certain contributions of Green and Racamier.