High incidence of goiter in patients treated with lithium carbonate.

The effects of lithium carbonate on thyroid was evaluated in 40 consecutive psychiatric patients on long-term treatment with this drug. Five patients had clinical and/or biochemical hypothyroidism. Twenty four (60%) subjects showed goiter of different size, including very large glands. A very high prevalence of goiter (87%) was observed in the 15 patients coming from a moderate endemic area. A lower incidence of goiter (44%) was found in subjects coming from non endemic areas. Goiter was associated with significantly elevated serum thyroglobulin concentration similar to that reported in endemic or sporadic nontoxic goiter. None of 25 psychiatric patients not receiving lithium therapy was hypothyroid and only three (12.5%) of them showed a small size goiter. These data indicate a very high prevalence of thyroid enlargement in patients on lithium therapy and suggest the opportunity to institute a prophylactic thyroid hormone treatment at least in subjects coming from endemic areas.