[The psychiatric illness of Vincent van Gogh]

Vincent van Gogh's illness has been the object of much speculation. Explanations as disparate as acute intermittent porphyria, epilepsy and schizophrenia have been proposed. Many of the diagnostic hypotheses, however, are based on partial or incomplete consideration of the biography and of the reports of his subjective experience in his letters to his brother. Karl Leonhard showed, in a detailed analysis of Vincent's biography, that both the course and symptoms of the disorder were consistent with the diagnosis of a cycloid psychosis (anxiety-elation psychosis). In the present paper, the diagnostic judgement of Leonhard is described and discussed in the light of independent research on van Gogh's letters, his works and biography. The bibliographical sources were investigated for information consistent with a cycloid psychosis, but also for information that might contradict this hypothesis. The course and symptoms of the disorder are presented as comprehensively and systematically as possible and are documented with the respective citations. Furthermore, the most important diagnoses proposed in the literature are critically discussed. Based on this investigation, it was possible to show that only the diagnosis of a cycloid psychosis allowed us to connect all the available information to a typical psychiatric syndrome.