Function of hypothalamo-pituitary thyroid axis in depressed patients.

Nineteen out of 51 depressed patients showed abnormal TSH response to TRH in terms of exaggerated, diminished and delayed responses. The basal value of T3 and its response to TRH were significantly lower in patients with delayed or diminished response than in the normal subjects. These results indicate that the dysfunction of the hypothalamo-pituitary thyroid axis plays an important role in the pathogenesis of depression.