Neuroendocrine abnormalities in recreational ecstasy (MDMA) users: is it ecstasy or cannabis?

Background: The purpose of this study was to investigate neuroendocrine function in ecstasy (3,4-methylenedioxymethamphetamine = MDMA) users and controls. Methods: Prolactin response to d-fenfluramine was assessed in abstinent ecstasy users with concomitant use of cannabis only (n = 24, male/female 13/11) and in two control groups: healthy nonusers (n = 13, female) and exclusive cannabis users (n = 7, male). Results: Prolactin response to d-fenfluramine was slightly blunted in female ecstasy users. Both male user samples exhibited a weak prolactin response to d-fenfluramine, but this was weaker in the group of cannabis users. Baseline prolactin and prolactin response to d-fenfluramine were associated with the extent of previous cannabis use. Conclusions: Endocrinological abnormalities of ecstasy users may be closely related to their coincident cannabis use. Cannabis use may be an important confound in endocrinological studies of ecstasy users and should be looked for more systematically in future studies.