RESUMEN
We investigated thyroid function in 46 [20 female and 26 male] psychiatric outpatients on lithium treatment by assessing triiodothyronine, thyroxine and thyroid stimulating hormone [TSH] levels. The presence of thyroid antibodies [anti-thyroid peroxidase and anti-thyroglobulin] was also assessed. Out of the 46 patients, 8 [17%] displayed overt hypothyroidism. Of the remaining patients, subclinical hypothyroidism was found in 16 patients [35%] and euthyroidism in 22 [48%]. Thyroid antibodies were present in 6 patients in the euthyroid group and 5 patients in the hypothyroid group. The Pearsor product-moment correlation results indicated positive association between TSH level and duration of lithium use and age of the patients with subclinical hypothyroidism. Duration of lithium use and age could be a reasonable indicator for screening asymptomatic patients for subclinical hypothyroidism after starting lithium treatment