Lithium-Carbonate-Induced Myxedema

After six months of lithium carbonate maintenance therapy, a myxedematous state was induced in a middle-aged manic-depressive man in whom results from basal thyroid function studies were found to be normal. The diagnosis was missed because it was assumed that his mental state and psychomotor retardation were manifestations of a shift to the depressive phase. The diagnosis of myxedema should be considered when a manic-depressive patient maintained with lithium carbonate develops sluggish mentation, apathy, and facial edema in the absence of the subjective experience of depression.