Hypothalamus-pituitary-adrenal system regulation and suicidal behavior in depression

Background: One of the most demanding tasks in psychiatry is to protect patients from suicidal attempts. Preventive strategies could be improved by increasing our knowledge on the pathophysiologic disturbances underlying this behavior. More than 70-80% of suicides occur in the context of depressive disorders, in which dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis is one of the most prominent neurobiological findings. So far data on the involvement of the HPA axis in the pathophysiology of suicidal behavior in depressed patients are controversial. Methods. In this retrospective study, we administered the combined dexamethasone-suppression/CRH stimulation (Dex/CRH) test to 310 patients with a depressive syndrome characterized at admission for acute and post suicidal behavior within the first 10 days after hospitalization. Results. Suicidal behavior in depressed patients, including past and recent suicide attempts as well as suicidal ideation was associated with a lower adrenocorticotropin and cortisol response in the combined Dex/CRH test, with lowest hormone levels observed in patients with a recent suicide attempt. Discussion: The findings suggest that suicidal behavior may alter HPA axis regulation in depressed patients, Large-scale prospective studies assessing neuroendocrine changes may help to develop predictors for an early identification of patients at risk, for committing suicide.