D-fenfluramine-induced prolactin and cortisol release in major depression: response to treatment

In order to test the effects of various biological treatments on serotonergic function in depression, twenty-one patients with a diagnosis of major depression underwent neuroendocrine challenge tests before and after treatment with either ECT, fluoxetine or amitriptyline. The serotonin (5-HT) releasing agent d-fenfluramine was used as a challenge drug and cortisol (CORT) and prolactin (PRL) plasma levels were monitored over a 5-h period. Overall PRL responses were significantly enhanced following pharmacotherapy irrespective of therapeutic outcome. Effective treatment in each case lowered baseline CORT levels but CORT response to d-fenfluramine remained blunted. Hypercortisolaemia may be involved in the impaired pretreatment PRL response as a strong inverse relationship was established, for the combined studies, between basal CORT plasma concentrations and PRL responses.