Thyroid hormone levels before unsuccessful antidepressant therapy are associated with later response to T3 augmentation

Abstract

Thyroid function was measured in 24 patients before antidepressant treatment, and following failure of acute desipramine treatment but before triiodothyronine (T3) augmentation. While all measures of thyroid function were within the euthyroid range, eventual T3 augmentation responders were found to have, prior to any antidepressant treatment, lower levels of TSH and higher levels of thyroxine (T4) and free thyroxine index (FTI) than non-responders. This suggests that T3 augmentation may be of particular importance in subjects with comparatively elevated levels of serum FTI.