[Hyperthyroidism after lithium withdrawal: coincidence or not?].

A 59 year-old manic-depressive woman treated with lithium for 10 years, developed hyperthyroidism three months after lithium withdrawal. The usual side effects on lithium on thyroid function include hypothyroidism and/or development of a goiter. Hyperthyroïdism occurring during lithium therapy is more rarely described. Hyperthyroidism has been exceptionally reported after lithium withdrawal, as in this case (five cases are recorded). The role of lithium in this pathology is controversial. Well-designed prospective studies are needed to clarify this question. Nevertheless, the effects of lithium on the thyroid metabolism are not always harmless and must prompt the clinicians to control the thyroid hormones before, during and after lithium therapy.