This paper discusses two aspects from the diagnostic discussion of a clinical case treated in a Centre for Psychosocial Care (CAPS). The case was analysed in accordance with the assumptions of the DSM-IV-TR and later under a psychoanalytic perspective. We present a discussion on the rationale adopted by psychiatric diagnosis that has a tendency to replace the major diagnostic categories specified by description of phenomena operationalised goals. On the other hand, we present the psychoanalytic logic which attempts to go beyond objective phenomena in order to bring the subject from his speech. In this article, we intend to highlight the consequences ensued in treatment conducted with both different diagnostic logics.