From Molecular Mechanisms to Therapeutic Strategies: Targeting the HPA Axis in Stress-Related Depression

Depression caused by chronic stress is usually characterized by anhedonia and despairing thoughts prevailing worldwide. The hypothalamic-pituitary-adrenal (HPA) axis is necessary in stress response and a major target for depression therapy. This book chapter explores the molecular mechanisms involved in the prognosis of depression and therapeutic strategies. The HPA axis not only regulates stress mechanisms through hormonal modulation but also physical behavior.  Chronic stress impairs this regulating mechanism, causing cortisol imbalance and depressive disorders and several factors, including genetic, neurobiological and neuroendocrinological dysregulation leading to HPA dysfunction. Recent therapeutic interventions include the integration of CRH receptors, glucocorticoid receptors and V1b receptor antagonists in the human system. Novel therapeutic techniques target oxytocin, FKBP5, and neuropeptide Y. Personalized therapy based on exploration of genetic makeup or biomarker guided intervention can be used to enhance efficacy by the use of emerging and new drug delivery approaches such as nanotechnology, gene therapy and optogenetics which also underscores the prospective pathways regarding targeted therapy. Critical challenges include the development of phenotypically relevant animal models that will not only improve translational frameworks but also deal with ethical issues. Prospective directions involve the refinement of personalized and integrated interventions for the holistic treatment of stress-induced depression.