Thyroid Dysfunction and Bipolar Disorder: A Literature Review Integrating Neurochemical, Endocrine, and Genetic Perspectives

Thyroid disorders are common in medicine, while bipolar disorders (BDs), though less frequent, are significant due to global prevalence, the economic burden on healthcare systems and long-term health implications, and the effects of psychiatric illness on quality of life. Clinical research has suggested thyroid hormone imbalances can cause psychiatric symptoms similar to the clinical features observed in BDs. Despite increased attention in this area of study, much remains unknown regarding how thyroid issues contribute to the development of BDs. This review explores the complex link between thyroid disorders and BDs, focusing on neurochemical dynamics, changes in the hypothalamic-pituitary-thyroid (HPT) axis, and genetic factors. Furthermore, this literature review examines the importance of understanding these factors in linking both conditions and emphasizes the necessity for therapies targeting their shared underlying mechanisms.