Background: Quality of attachment relations between adolescents and their parents and peers may be related to early maladaptive schemas as well as to symptoms of depression. Aims: The aim of the current study was to assess whether schema domains and maladaptive schemas mediate the relation between indices of quality of attachment relationships with parents and peers and symptoms of depression in non-clinical adolescents (N = 222). Method: A battery of questionnaires was completed, including measures of quality of attachment relations, maladaptive schemas, and depression. Results: The schema domains of disconnection and rejection and other-directedness mediated the relation between quality of attachment relationships and symptoms of depression. More precisely, the schemas- mistrust/abuse and social isolation mediated the relation between trust in parents and depressive symptoms, whereas the schemas- social isolation and self-sacrifice mediated the relation between alienation from peers and symptoms of depression. Conclusions: The mediation analyses suggest that treatment of adolescent depression could be focused on both attachment bonds and on changing maladaptive schemas.