This case study originates in the context of the Frankfurt Depression Study (LAC) which investigates long term therapies of chronically depressives. At the centre of the case study is the psychoanalytic therapy of a young woman who, inhibited in the development of her feminity and her autonomy, found herself helpless vis-à-vis her depression. A crises caused by difficulties in adolescent detachment processes and feelings of insufficiency had triggered the depression. The description of the distinctive contents of the treatment and its progression illustrates the orientation of a manual derived from the Tavistock Adult Depression Study (TADS) which served as a conceptual framework to the study. Findings gathered in the course of the therapy are verified by an expert validation based on the Three-Level Model of Chlinical Observation developed by the Clinical Research Group of the International Psychoanalytic Association (IPA). This is compared with the results of the Operationalized Psychodynamic Diagnostic (OPD) system. The Heidelberg Structural Scale (HSCS) is used as an indicator of treatment effectiveness. In this specific case psychoanalytic therapy achieved improved social functionating, higher self-distinction and acceptance, the ability to enter into a partnership, and the reduction of medication together with a decline of absent days.