Lithium-induced thyroid disorders: a prevalence study.

A group of 116 lithium-treated patients (53 men, 63 women) with predominant diagnoses of affective disorders were systematically examined for the presence of thyroid disorders. Nine (7.8%) patients (2 men, 7 women) were found to suffer from hypothyroidism after a mean of 3.4 years of lithium therapy. An increase in thyroid-stimulating hormone without clinical hypothyroidism was noted in 2 (1.7%) patients (both men). Hyperthyroidism with a full-blown picture of thyrotoxic nodular goiter was noted in 1 woman, and temporary increases in thyroxine and triiodothyronine were noted in another woman. These findings are discussed in light of other studies.