This review combines hypotheses concerning ecstasy use and serotonin syndrome with a more general review of MDMA/ecstasy related research, and was probably written for the medical and scientific audience. The review briefly discusses serotonin syndrome and its relevance to ecstasy use, particularly in a club or rave environment. Parrott states, without presenting confirming evidence, that symptoms of mild serotonin syndrome are common among ecstasy users and that high ambient temperature and crowded spaces increase serotonin syndrome. The review is poorly organized, and no attempt is made to relate findings from each type of MDMA research (subjective effects, potential neurotoxicity) to serotonin syndrome. Most of the same criticisms concerning an earlier review by the same author appearing in Human Psychopharmacology (Parrott 2001) apply to this paper as well. These include treating some speculations as if they were fact, failure to understand the intent of those wishing to use MDMA in psychotherapy and incomplete coverage of the range of models explaining MDMA neurotoxicity. However, the author does make a few interesting observations, such as that concerning a strong correlation between nicotine (cigarette) consumption and ecstasy use.