The subjective effects of MDMA and mCPP in moderate MDMA users

The present study is part of a research program designed to better understa nd the neurochemical mechanisms underlying the abuse liability of 3,4-methy lenedioxymethamphetamine (MDMA) in humans. In these studies, MDMA will be c ompared to prototypical dopamine (D-amphetamine) and serotonin (meta-chloro phenylpiperazine, mCPP) releasing agents on a variety of measures related t o dependence. In order to determine an acceptable dose range (safe but acti ve) of MDMA and mCPP for these studies, moderate MDMA users were administer ed escalating doses of MDMA (75, 110 and 145 mg/70 kg) and mCPP (17.5, 35 a nd 52.5 mg/70 kg). Each participant received a single dose under controlled laboratory conditions, i.e. this was a six-group design with a separate gr oup for each dose. There were five participants tested in each group. MDMA increased blood pressure and heart rate whereas mCPP had no effect on these physiological measures. MDMA produced increases in subjective effects indi cative of both stimulant (increases in POMS Elation, ARCI Amphetamine, VAS High and Stimulated scale scores) and hallucinogenic effects (increases on five of the six scales of the Hallucinogenic Rating Scale). mCPP produced s imilar stimulant effects (e.g. increases on POMS Elation, VAS High and Stim ulated), as well as hallucinogenic effects (four of the six scales of the H allucinogenic Rating Scale), which has not been observed in previous studie s. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.