Thyroid function and bipolar affective disorder.
Thyroid function tests and life course of illness were evaluated in 42 patients with bipolar affective disorder who had received at least 3 months of lithium carbonate treatment. Eight of 42 patients (19%) required thyroid replacement or had evidence of subclinical hypothyroidism associated with lithium treatment. Abnormalities of thyroid function were related to female sex and duration of lithium treatment but not to a rapid-cycling course of illness.