Free triiodothyronine (T3) and thyroxine (T4) in a group of unipolar depressed patients and normal subjects

Abstract We examined levels of free triiodothyronine (fT 3 ) and free thyroxine (fT 4 ) in serum from a group of 32 patients with unipolar major depression and 46 normal control subjects using the Amerlex (Amersham, Arlington Heights, IL) RIA procedures for these hormones. Free T 3 levels were significantly lower ( p 3 levels were lower ( p 3 levels than did the female control subjects (5.09 ± 1.06 pmol/L), but the difference was not statistically significant. Lower fT 3 levels were also observed in melacholic depressed patients when compared with nonmelancholic depressed patients or when compared with normal control subjects. No differences in fT 4 were observed between groups in this study.