A sample of 96 in-patients with schizophrenia were assessed at the end of a 2-week medication-free period to determine whether rapid eye movement (REM) sleep abnormalities & cortisol response to the dexamethasone suppression test (DST) differentiate between patients with schizophrenia who have or do not have a history of suicidal behaviour. No significant relationship between suicidal behaviour & DST non-suppression were found. However, this study does confirm a previous finding suggesting an association between REM sleep abnormalities & suicidal behaviour in schizophrenia. (LC) (30 refs)