background Traumatic events were a risk factor for the former diagnosis 'hysterical psychosis'. Nowadays psychoses are rarely associated with trauma. Nonetheless research shows a relationship between psychoses and reported trauma.
aim To discuss research of trauma, posttraumatic stress symptoms and dissociative symptoms in combination with psychoses.
method Literature study by means of a Medline search, using as keywords 'psychosis and dissociation', 'psychosis and PTSD', 'dissociative psychosis', 'hysterical psychosis' and 'schizophrenia and dissociation'.
results The prevalence of trauma and posttraumatic stress disorder is high among psychotic patients and the prevalence of dissociation is substantial. Traumatic experiences can immediately precede a psychosis and complicate its course. Experiencing a psychosis can lead to posttraumatic stress disorder. Delusions and hallucinations occur more often in psychotic patients who report trauma than in psychotic patients who don't.
conclusion Research into the relationship between trauma, trauma-related psychopathology and psychosis serves the development of theories on psychotic disorders as well as the diagnosis and treatment. Dissociative and posttraumatic stress symptoms are difficult to distinguish from psychotic symptoms. More research is indicated for the proposed diagnostic category 'reactive dissociative psychosis'.