DO THE ENDOCRINE AND SUBJECTIVE EFFECTS OF D-FENFLURAMINE PREDICT RESPONSE TO SELECTIVE SEROTONIN REUPTAKE INHIBITORS

Thirty drug-free depressed patients underwent double-blind, placebo-co ntrolled, neuroendocrine testing with the serotonin (5-HT) releasing a gent d-fenfluramine prior to receiving treatment with a selective sero tonin reuptake inhibitor (SSRI) for 8 weeks. Compared to placebo, d-fe nfluramine significantly elevated plasma levels of prolactin and corti sol, increased subjective visual analogue ratings of ''light headed'' and decreased ratings of ''desire to eat''. Of the 30 patients studied , 17 responded to treatment but none of the pretreatment responses to d-fenfluramine distinguished patients who responded to SSRI treatment from those who did not. The results suggest that the clinical response to SSRI administration may be independent of pretreatment brain 5-HT function. Another possibility is that the neuroendocrine and subjectiv e effects of d-fenfluramine are mediated by 5-HT mechanisms other than those involved in the antidepressant effect of SSRIs.