This book is the product of my Master's dissertation, which was presented to the Postgraduate Programme of the Faculty of Philosophy and Human Sciences of the Federal University of Minas Gerais. It was born out of some questions raised during my professional career as a psychologist in a public psychiatric hospital in the state of Minas Gerais. In this emergency and inpatient psychiatric service, which is also a teaching hospital and constitutes a space for research, some theoretical-clinical impasses were posed in our clinical practice, which motivated us to confront some existing foundations and diagnostic guidelines in the psychoanalytic field.