Comparison of fluorescent polarization immunoassay and radioimmunoassay in measuring cortisol levels in prepubertal depressed children.

Cortisol levels of 21 hospitalized prepubertal depressed children given the dexamethasone suppression test (DST) were measured by radioimmunoassay and by fluorescent polarization immunoassay, a new assay method. Correlation analyses demonstrated a highly significant linear relationship between the two methods of measuring cortisol. Thus, it may be possible to use fluorescent polarization immunoassay to measure cortisol levels in children undergoing the DST.