BASE-LINE THYROID-HORMONES IN DEPRESSED AND NONDEPRESSED PRE-PUBERTALAND EARLY-PUBERTAL BOYS AND GIRLS

Objective: To examine baseline thyroid hormones in a large group of we ll-characterized pre-and early-pubertal boys and girls who met criteri a for major depressive disorder (MDD) and a comparison group of normal children without psychiatric disorders. Methods: 45 children with MDD (10.6 years +/- 1.4year) and 56 healthy controls (10.0 +/- 1.7 year) who participated in a large, psychobiologic protocol are included in t his report. As part of the screening for eligibility, baseline samples were drawn for thyroxine (T4), triiodothyronine (T3) uptake, and thyr oid stimulating hormone (TSH). Free thyroxine index (FTI) also was com puted. Results: Between-group analyses were carried out controlling fo r Various demographic variables significantly related to thyroid hormo nes [e.g. age, gender, body mass index (BMI) and their interactions]. For many hormones there were significant effects for age and gender. F or T4, MDD boys had lower T4 compared with boys in the normal group. N o differences were noted between MDD girls and normal girls. For TSH, MDD boys had lower concentrations compared with normal boys while no d ifferences were noted in girls. For T3 uptake, the MDD group had lower uptake compared with the normal group. For Fn, there were no group di fferences. Similar to most studies of adults with depression, all our subjects were euthyroid. Unlike the adult studies, we found lower T4 c oncentrations in the MDD group rather than higher. Group differences i n thyroid hormones were noted primarily in boys. The large sample size of this study allowed for the control of multiple variables, which ha s not been done in past studies. Without such controls, true findings may be masked in other studies of depression. Thus, our findings sugge st the possibility of developmental differences in the relation of thy roid hormone and depression. (C) 1997 Elsevier Science Ltd.