One hundred years ago Eugen Bleuler published his book, Dementia praecox or the group of schizophrenias. In it, he proposed the term schizophrenia to describe the most disturbed of his hospital patients, a word literally meaning “split mind” and close in many respects to contemporary conceptions of dissociation. Since that time, while the meaning of the diagnostic entity schizophrenia has changed considerably, its relation to trauma and dissociative disorders remains a complex and confusing one. Here, I want to briefly summarise our current understanding by discussing four important issues bearing on different aspects of the relation between trauma, dissociation, psychotic symptoms, and schizophrenia.