This critique was written in response to a commentary and critique of MDMA research written by Cole and colleagues (Cole et al. 2002). Parrott draws on evidence from a number of studies that found reduced cognitive function in ecstasy users as indicating MDMA neurotoxicity. His arguments rest on both strong studies, as the prospective study conducted by Zakzanis and Young (2001), and on weaker study designs, as those relying on self-reported memory problems (Heffernan et al. 2001; Rodgers et al. 2001). Parrott discusses research in non-human animals, but does not address issues relating to differences in doses used in these studies and doses typically used in ecstasy users. He also voices support for a specific model of MDMA neurotoxicity without discussing well-known competing models. Because his own studies have failed to find differences in degree of positive mood reported acutely after ecstasy use and positive mood reported in those not using ecstasy, Parrott doubts that people use ecstasy for its mood-elevating acute effects. However, these findings cannot negate peopleÕs stated reasons for using ecstasy, since ecstasy may still produce an increase in positive mood, even if that increase is no greater than the increase produced by other substances (e.g. ethanol) or settings.