[Delusion and understanding (author's transl)].

This paper presents the psychodynamic investigation of a case of schizophrenia, which developed on the basis of a LSD-psychosis. It is a contribution to a treatment of schizophrenia, in which the coexistence of biological and psychological factors is taken into consideration. Biological premises do not invalidate the psychological understanding of many symptoms. Psychodynamic experience permits the psychiatrist to encounter the patient adaquately, even if the possibility for a long psychotherapeutic treatment is absent.