Journal of Thyroid Disorders & Therapy
Open Access

Abstract

Lithium Therapy and Thyroid Disorders

Daniel Thut and David Cheng

Lithium is a first-line treatment for bipolar disorder and is associated with a variety of thyroid toxicities. The pathophysiology is complex but may include inhibiting the formation and release of thyroid hormones, increasing intrathyroidal iodine content, altering the hypothalamus-pituitary axis, and stimulating various cellular pathways such as insulin-like growth factor, tyrosine kinase, and Wnt/β-catenin signaling. Goiter, the most common manifestation, is noted in up to 50% of patients, which is followed by hypothyroidism seen in approximately 20% of patients. The incidence of hyperthyroidism is less frequent in lithium-treated patients but is still higher than in the general population. By decreasing thyroid hormone release, lithium can be used to treat hyperthyroidism, but limited data supporting its effectiveness and lithium’s associated toxicity limit its use to refractory cases only. Lithium can also increase retention of radioactive iodine in thyroid tissue and therefore has the potential to be an adjunct therapy for hyperthyroidism and thyroid cancer, but more research in this area is needed.