The prolactin response to thyrotropin-releasing hormone in depressed patients and normal subjects.

The prolactin (PRL) response to thyrotropin-releasing hormone (TRH) was studied in depressed patients (while ill or during remission) and in normal volunteers. Depressed women were shown to have lower basal PRL and lower PRL after TRH, but similar proportional PRL responses, compared to normal women. Depressed women also had basal thyroxine levels that were higher than those of the control women. No significant changes in PRL were noted in depressed men; in fact, there was almost complete overlap of all PRL variables between depressed and normal male subjects. Examination of the responses of PRL and of thyrotropin (TSH) to TRH revealed a significant positive relationship between the two in depressed women, but no association in men.