Thyroid abnormalities in lithium-treated patients with bipolar affective disorder

The thyroid functions of 42 subjects with bipolar affective disorder receiving regular lithium therapy were analysed and their thyroid glands were examined by ultrasonography. Following the receipt of lithium therapy (duration 4 - 156 months), three subjects displayed subclinical hypothyroidism (7.1%), three subclinical hyperthyroidism (7.1%) and one hyperthyroidism (2.4%). Moreover, goitre was detected in 16 (38.1%) subjects. An increase in the conversion of free thyroxine (T-4) to free tri-iodothyrosine (T-3), which is an indication of mild thyroid dysfunction, was identified in 20 (47.6%) subjects, and was mostly seen in male subjects under 40 years of age and in those having weight gain. In conclusion, some thyroid dysfunctions were observed in the patients treated with lithium.