Psychoanalytic theory offers a varied conceptual system for considering psychosis by providing a coherent representation of the anxieties and processes at work in adult patients. But at the practical clinical level, it is not enough simply to ‘think about psychosis’ and have a theoretical system in place. The therapist must also ‘have psychosis in mind’, that is, get to grips with its forms of logic, gain familiarity with its workings, and learn to understand and accept the effects it has on the therapeutic relationship and on their own expectations. Clinicians engaged in this type of work must be able to tolerate getting back in touch with processes deemed archaic at the core of their own psychological functioning, which will impact their ability to listen and think. These chaotic processes demand a change of approach since they cause a ‘desymbolisation’ that perturbs the internal mental structure of the therapist. This ‘desymbolisation’ is therefore the locus of the therapeutic work, which must attempt to render it comprehensible and represent it. A case study illustrates these processes.