This paper features a reply to comments authored by Morgan (2002), Croft (2002) and Parrott (2002) that critiqued a review of MDMA research (Cole et al. 2002a). Focusing on comments made by Parrott, the authors address models of neurotoxicity, and the appropriateness of drawing conclusions about possible neurotoxicity in human users from findings in non-human animals. The authors note that the same cognitive deficits associated with ecstasy use may also be associated with other drugs that are demonstrably not neurotoxic to serotonin axons, such as cocaine and ethanol. The authors contradict claims by Parrott that people attend hot, crowded dance events to enhance the effects of ecstasy and that use is driven only by desire for euphoria. Government permission for conducting studies of therapeutic uses of MDMA is described as an indicator that governmental regulatory agencies are also skeptical of findings of ecstasy-related psychopathology or reduction in verbal memory. However, it should be noted that proposed or ongoing studies do not involve regular MDMA administration, and agencies may be responding to the lack of evidence for harm occurring after the administration of a few spaced doses of MDMA. In referring to findings of reduced cognitive function in ecstasy users, the authors argue that it is important to distinguish clinical significance from statistical significance, and voice concern that people whose everyday function is not impaired may perceive themselves as being impaired after learning about findings of cognitive deficits in ecstasy users. The response does not address issues relating degree of certainty conferred by number of studies versus quality of studies, or the feasibility of conducting prospective studies of ecstasy users.