Motherhood is a potentially disruptive experience in the life cycle. When the psychiatric diagnosis is added to this experience, it can become even more complex. Understanding the diagnostic categories as semiotic mediators, the present article seeks to analyze, through a narrative, the ways in which a woman diagnosed with a mental disorder gives meaning to her psychic suffering and the ways she integrates it into her conception of herself. It is proposed that in the case studied, in the face of a situation permeated by ambivalence, the diagnosis appears as a strong generalized sign which, while encompassing a series of personal experiences, inhibits the possibility of new subjective constructions. It is concluded that, as a sign, the psychiatric diagnosis should be analyzed in its various microgenetic semiotic dimensions, in order to better clarify its implications for the experience of the diagnosed person.