CENTRAL SEROTONERGIC CHANGES FOLLOWING ANTIDEPRESSANT TREATMENT - A NEUROENDOCRINE ASSESSMENT

We employed a neuroendocrine challenge paradigm to study the effects o f antidepressant treatment on serotonergic systems in depressed patien ts. We compared the maximum prolactin response to intravenous clomipra mine (CMI) in depressed patients who responded to antidepressant treat ment to that of nonresponders. Pretreatment baseline prolactin concent rations and pretreatment prolactin responses to clomipramine challenge were not different in responders compared to nonresponders. However, following antidepressant treatment, the 6 responders demonstrated a si gnificant change in their clomipramine challenge test results, as indi cated by an increase in prolactin responses. In contrast, the 7 nonres ponders did not demonstrate a change in their prolactin response to cl omipramine challenge following treatment. These data support the hypot hesis that serotonergic system dysfunction, as manifested by blunted p rolactin response to clomipramine challenge, tends to normalize after successful treatment for depression, and that abnormal serotonergic fu nction may be a state-dependent characteristic.