This paper explores how the diagnosis of mental disorder may affect the diagnosed subject’s self-concept by supplying an account that emphasizes the influence of autobiographical and social narratives on self-understanding. It focuses primarily on the diagnoses made according to the criteria provided by the Diagnostic Statistical Manual of Mental Disorders (DSM), and suggests that the DSM diagnosis may function as a source of narrative that affects the subject’s self-concept. Engaging in this analysis by appealing to autobiographies and memoirs written by people diagnosed with mental disorder, the paper concludes that a DSM diagnosis is a double-edged sword for self- concept. On the one hand, it sets the subject’s experience in an established classificatory system which can facilitate self-understanding by providing insight into subject’s condition and guiding her personal growth, as well as treatment and recovery. In this sense, the DSM diagnosis may have positive repercussions on self-development. On the other hand, however, given the DSM’s symptom-based approach and its adoption of the Biomedical Disease model, a diagnosis may force the subject to make sense of her condition divorced from other elements in her life that may be affecting her mental- health. It may lead her frame her experience only as an irreversible imbalance. This form of self-understanding may set limits on the subject’s hopes of recovery and may create impediments to her flourishing.