Revista de Psiquiatria do Rio Grande do Sul Print version ISSN 0101-8108

BACKGROUNDS: A diagnostic simulation exercise was carried out using John Nash's case (the 1994 Mathematics Nobel Prize winner and described as suffering from schizophrenia) to introduce the Operational Criteria Checklist for Psychotic Illness (OPCRIT) and discuss the uncertain boundaries between some of the diagnostic categories presented by the instrument, as well as the use of dimensional diagnosis in psychiatry. METHODS: Data were obtained from John Nash's biography (written by Sylvia Nasar) and from the movie A Beautiful Mind. The authors discussed the symptoms shown in both the biography and the movie and then entered data into the OPCRIT program. Because consensus was not reached in some items, two additional simulations were carried out. In these, three items were modified, in order to investigate the effects of these changes on diagnosis: thoughts racing (31st item), increased sociability (53rd item), and relationship psychotic/affective symptoms (52nd item).