The presence of antithyroid antibodies in patients with affective and nonaffective psychiatric disorders.

We determined the frequency of antithyroglobulin and antimicrosomal antibodies in 173 consecutively admitted psychiatric inpatients. (We found antithyroid antibodies in 8% (5/65) of patients with DSM-III major depression, 13% (4/31) with biploar disorder, and in 0% (0/4) of those with schizoaffective disorder.) The rate of antibody occurrence was unrelated to lithium exposure either within individual diagnostic categories or for the sample as a whole. The overall frequency of positive antithyroid antibody titers in patients with DSM-III affective disorder, 9% (9/99), did not differ from that in patients with nonaffective disorders, 10% (7/68). However, patients with bipolar affective disorder-mixed or bipolar affective disorder-depressed had a higher rate of positive antithyroid antibody titers than other patients. Our findings confirm earlier reports that thyroid disorders may be particularly common in patients with bipolar affective disorder, even in the absence of lithium exposure. However, as antithyroid antibodies also occurred at a relatively high rate in nonaffective disorders, the possible psychiatric effects of autoimmune thyroiditis do not appear to be limited to affective dysregulation.