Endocrinological Treatment Targets for Depressive Disorder.

Depressive disorder exhibits heterogeneity in clinical presentation, progression, and treatment outcomes. While conventional antidepressants based on the monoamine hypothesis benefit many patients, a significant proportion remains unresponsive or fails to fully recover. An individualized integrative treatment approach, considering diverse pathophysiologies, holds promise for these individuals. The endocrine system, governing physiological regulation and organ homeostasis, plays a pivotal role in central nervous system functions. Dysregulations in endocrine system are major cause of depressive disorder due to other medical conditions. Subtle endocrine abnormalities, such as subclinical hypothyroidism, are associated with depression. Conversely, depressive disorder correlates with endocrine-related biomarkers. Fluctuations in sex hormone levels related to female reproduction, elevate depression risk in susceptible subjects. Consequently, extensive research has explored treatment strategies involving the endocrine system. Treatment guidelines recommend tri-iodothyronine augmentation for resistant depression, while allopregnanolone analogs have gained approval for postpartum depression, with ongoing investigations for broader depressive disorders. This book chapter will introduce the relationship between the endocrine system and depressive disorders, presenting clinical findings on neuroendocrinological treatments for depression.