Abstract Background Stories written under musical induction allow studying symbolic figures emerging during the psychotherapeutic process. During multimodal arts psychotherapy, based on a combination of active music therapy and the production of stories under musical induction, the archetype of the alter ego frequently appears in texts written by adolescents (Schiltz, 2008). This archetype shows its different facets during the psychotherapeutic process. Methods and research questions With the help of a qualitative study, based on the phenomenological content analysis of the TAT and the stories written under musical induction with N=52 students suffering from emotional (subgroup I) or conduct disorders (subgroup D), we answered the following questions: • Can we recognise in these symbols compensatory features regarding the person’s initial problems? • Do they gradually expand during the therapeutic progress, so that they reflect the integration of the hidden and split parts of the self? • What is generally their role in the adolescents’ search for identity, beyond the realm of the pathology? Results The results of the study opened psychotherapeutic perspectives for tertiary prevention in adolescence.