Zhao Y, Wang N, Wen SW, et al. - Researchers performed a retrospective cohort study in the Second Affiliated Hospital of Xinxiang Medical University between January 2016 and December 2018 to explore the connection between mirtazapine use and hypothyroxinemia in patients affected by major depressive disorder. Patients with major depression disorder who were admitted to the hospital for treatment during the study period and had thyroid tests before and after treatment were included. The final analysis included a total of 220 eligible patients. Findings suggested an association of mirtazapine use with the increased risk of developing hypothyroxinemia. The underlying mechanism could be a change in the central set point of thyroid homeostasis, in which the pituitary was possibly less sensitive to lower levels of thyroid hormones.