The Centre for Psychoanalysis of the Mental Health Association in the 13th district of Paris is part of a community psychiatric public facility. It specializes in non-neurotic pathologies. The Centre offers several forms of psychoanalytic therapy for more than 200 patients, suffering from psychoses or severe borderline personality disorders. This double particularity of the Centre (public mental health facility and type of patients) has led it to develop distinct treatment techniques (for example, psychodrama) and to give special attention to the conditions of countertransference, as the demand for therapy is a challenge for both psychoanalysts and the psychiatric team who care for patients and refer them to the Centre. Over four decades, the analysts of the Centre have elaborated certain theoretical concepts (transference investment, thirdness and the ‘third person’, processual interpretation, ‘presence’ of the analyst, erotomaniac position …) that take into account the necessity of adapting the psychoanalytic approach to working with these categories of patients.