Abnormal neuroendocrine responsivity to acute i.v. clomipramine challenge in depressed patients

The neuroendocrine responsivity to an acute serotonergic challenge with low-dose i.v. clomipramine was studied in seven drug-free depressed patients and seven age-matched healthy control subjects. The depressed patients had higher baseline prolactin concentrations than the healthy subjects, and their prolactin response to clomipramine, assessed as either the percent of baseline or the log-transformed concentration, was significantly different (delayed and blunted peak response) compared to healthy controls. The growth hormone response was exaggerated in the depressed patients, and there were also trends toward blunting in their cortisol and adrenocorticotropic hormone responses. These results are consistent with previous findings of altered neuroendocrine responses to a variety of putative serotonin agonists in depressed patients.