Pharmacological modulation of HPA axis in depression New avenues for potential therapeutic benefits

Abstract

One of the most consistent biological findings in major depression (MDD) is the altered activity of the hypothalamic-pituitaryadrenal (HPA) axis. It is not surprising that glucocorticoid receptor (GR), the common mechanism for stress-related changes in brain function, is a potential target of antidepressant drugs and therapies. All effective antidepressant treatments should trigger and maintain GR-related cellular processes necessary for recovery from MDD. Classic antidepressants act indirectly, by affecting the dynamic interplay between serotonin neurotransmission and HPA. On the other hand, certain compounds acting at suprahypothalamic, HPA axis, glucocorticoid receptors, and post-receptor levels are being considered as new therapeutic options with the potential to modulate the aforementioned system in affective disorders directly. Different classes of drugs pharmacologically modify the HPA axis. This article summarizes the efficacy of classic antidepressants, as well as drugs classified as "antiglucocorticoids" (GR agonists, GR antagonists, dehydroepiandrosterone- DHEA, steroid synthesis inhibitors drugs, etc) in their capacity to heal glucocorticoid-mediated damage in depression. New avenues investigating the potential therapeutic benefits of antiglucocorticoids in affective disorders are at the proof-of-concept stage and future developments in this area deserve the full attention of psychiatrists and neuroscientists, as the current pharmacological treatment of MDD is far from perfect. © Medicinska naklada-Zagreb, Croatia.