The anterior pituitary responds normally to protirelin in obsessive‐compulsive disorder: evidence to support a neuroendocrine serotonergic deficit

The prolactin and thyroid-stimulating hormone (TSH) responses to protirelin and the prolactin and cortisol responses to d-fenfluramine were measured in 8 outpatients with DSM-III-R obsessive-compulsive disorder (OCD). The results were compared to those in 8 age- and sex-matched healthy controls. The responses to d-fenfluramine were significantly attenuated in the OCD patients, but there was no significant difference between the responses to protirelin in OCD patients and healthy controls. The data suggest that, in OCD, blunting of prolactin responses to the serotonin-releasing agent d-fenfluramine is due to a central abnormality and not due to a pituitary deficit.