High intensity dependence of auditory evoked dipole source activity indicates decreased serotonergic activity in abstinent ecstasy (MDMA) users

Neurotoxic damage of central serotonergic systems has been demonstrated in numerous animal studies after exposure to methylenedioxyamphetamines (ecsta sy). A high intensity dependence of auditory evoked potentials and, particu larly, of the tangential N1/P2 source activity has been associated with low levels of serotonergic neurotransmission in humans. We performed an audito ry evoked potentials study in 28 abstinent recreational ecstasy users and t wo equally sized groups of cannabis users and nonusers and two equally size d groups of cannabis users and nonusers. The ecstasy users exhibited an inc rease of the amplitude of the tangential N1/P2 source activity with higher stimulus intensities; whereas, both control groups failed to exhibit this f eature. These data are in line with the hypothesis that abstinent ecstasy u sers present with diminished central serotonergic activity. This feature of information processing is probably related to the well-recognized neurotox ic potential of ecstasy. Our data indicate that recreational ecstasy use ma y cause long-term alterations in the function (and possibly structure of th e human brain). (C) 2000 American College of Neuropsychopharmacology. Publi shed by Elsevier Science Inc.