The dexamethasone suppression test in psychiatric disorders: A recent reevaluation | [Test di soppressione al desametazone nella patologia psichiatrica: Una recente rivalutazione]

Aim. The aim of the present study was to review the currently available literature on the role of the dexamethasone suppression test (DST) in psychiatry. DST is a specific test exploring the functionality of the hypothalamic-pituitary-adrenal (HPA) axis by the administration of dexamethasone, a synthetic steroid that in normal conditions inhibits the synthesis of endogemous corticosteroids. Methods. The main studies on the topic were identified with a MEDLINE search (from 1971) including English and non-English journals and books. Results. Several studies showed that a positive DST (indicating non-suppression of the HPA axis), was more frequent in psychiatric disorders, especially in depression, than in healthy patients, although negative results were also reported. Discussion. In the past decades, DST was considered a marker of depression and was used as a screening test for this disorder. At the end of eighties, there was a dramatic reduction in the number of studies carried out on this topic, despite a lack of agreement on the role of the HPA axis in psychiatric disorders. Recently, new evidence on stress-related neuroendocrine changes in animal models has focused attention again on the role of the HPA axis as a central element in the pathogenesis of these conditions. Today DST can still be considered the most appropriate tool for the evaluation of the HPA axis. Measurement of salivary cortisol appears to be a valuable and convenient alternative to the measurement of plasma cortisol.